: 62mm Operation pressure: 12kg Length after use: 75FT, 23M Expansion ratio: 1:3 Elastic resilience: 1. As a rule, their modern design assumes use of carbon-carbon materials without regenerative cooling. Utilisation - 10 litres tank. The focus of the study is on the structure of the fluid and wave phenomena associated with the flow separation. 72 expansion ratio, while a 7. (2) The effect of a surfactant on the water/concentrate solution; allows the water. Each nozzle has a carbon cloth liner that erodes and chars during firing. During 1973-76, extensive calibration testing of the Helley-Smith sampler was conducted in the field. The self-educting function is not available on these Hydro-Chem nozzles. The nozzle expansion ratio of each booster beginning with the STS-8 mission is 7-to-79. 62 and the diameter of throat was 77. Nozzle expansion conditions •Three cases are possible: 1) p e < p a → over-expanded nozzle 2) p e = p a → adapted nozzle 3) p e > p a → under-expanded nozzle •In cases (1) and (3), pressure adjusts to ambient conditions through shock waves outside the nozzle •For a given nozzle geometry, thrust is maximum when nozzle is adapted. A relatively high nozzle expansion ratio was chosen for most Warp-9 motors not only to maximize delivered propellant specific impulse but also to help produce thrust levels as high as possible. c ¼ 6:28 MPa, a ratio of specific heats of c ¼ 1:17, and a nozzle expansion ratio yielding an exit value of e e ¼ 0:017. Nozzle expansion ratio increased from 9. The abrupt expansion was formed, by inserting, into the main tube, a perspex nozzle block with the nozzle contours shaped to a standard ASME long-radius profile. Chapter Eleven/Normal shock in converging–diverging nozzles ----- 3-6 ch. Its use in 9-5/8" cased wells is being investigated. 0 lbm/lb-mol. In both situations, high nozzle expansion ratios (ERs) are created, and shockwaves may be produced from the nozzles. Medium expansion foams may be used to suppress the vaporization of hazardous chemicals. During 1973-76, extensive calibration testing of the Helley-Smith sampler was conducted in the field. JET Color: Red Package includes: 1 x Garden Water Hose 1 x Squirt Gun 1 x User Manual Specifications: Material: Natural latex tube. 5 shows the actual expansion of steam through nozzle. You can change the shape of the diverging section by clicking the area shaded with '+' signs close to the line representing the diverging section. 02 Nozzle spray type: 1. The file planar_moc. In the present work, the feasibility of an arc-based design method for generation of. er_from_p (p_c, p_e, gamma) ¶ Find the nozzle expansion ratio from the chamber and exit pressures. performance of plug nozzles is then compared to that of linear-walled nozzles for equal pressure ratios, Reynolds numbers, and expansion ratios. • When the number of full range pressure cycles is greater than 7000 and the nozzle is subject to external loads. ber, the nozzle losses were sufficiently large to result in measured thrust coefficients. 62 and the diameter of throat was 88. The expansion ratio is the amount of finished expanded foam that will be produced using the correct nozzle. #: return the tuple (IspAmb, mode) #: Use throat gam to run ideal separation calculations. FOAMJET can be quickly attached to any TFT QUADRAFOG, ULTIMATIC 125, MIDMATIC, MID-FORCE, HANDLINE, DUAL-FORCE, METRO 0, METRO 1, OR METRO 2 series of TFT nozzles; When used with AFFF and Class A foams, the FOAMJET can develop expansion ratios of 6:1; Lightweight, low-expansion foam-making, air-aspirating attachment; Simple, rugged and dependable. For these reasons, fixed convergent nozzles are well suited to subsonic applications. National Foam’s HI-EX® Water Powered High Expansion Foam Generators are designed to achieve expansion rates of 350 to 600 gallons of foam for every one gallon of foam solution, depending on the. The all-axis gimbaling capability is 8 degrees. Specific impulse is the total impulse per unit weight of. Questions? Can this nozzle ever produce a supersonic flow in the. Each device will produce a specific foam quality, such as finished-foam expansion ratio and foam blanket 25 percent drain time. Finally, suggestions for when, where, and how to apply foams for vapor control are presented. nozzle-expansion ratio. The pressure ratio is the pressure at the nozzle exit to the combustion chamber pressure. Fixed or automatic fog nozzles, air aspirating attachments and high-expansion foam generators introduce different volumes of air into foam solution to create various finished-foam blanket qualities. The ratio between the jet exit and ambient static pressures is called the under-expansion ratio. A stream of foam solution is sprayed at high speed to an expansion net, drawing into the body the air required and producing foam with an expansion ratio of about 1:20. 3mm, representations of A/B power setting on ground labeled as type A; b) the nozzle expansion ratio was 1. Chamber pressure 61. 5 on command for optimized propellant utilization during the mission. The all-axis gimbaling capability is 8 degrees. 1: UHP P-19 Ultra High Pressure flow characterization results. If you want to go beyond the critical expansion ratio in a converging diverging nozzle, the. The expansion ratio varies but a 10:1 expansion ratio is a good number to. The Mach number at the nozzle exit is given by the perfect gas expansion expression (2. The higher the expansion ratio, the more efficient the nozzle is. 62 and the diameter of throat was 77. The best Nozzle Pressure Ratio (NPR) values are found to be 24. In many propulsive applicat ions, the squared area ratio e e varies between 0. Ratio of the cross-sectional area for gas flow at the exit of a nozzle to the cross-sectional area available for gas flow at the throat. How to find nozzle exit pressure? the user to apply an efficiency factor to account for all of the factors that effect the overall efficiency of the nozzle. As the ambient pressure is reduced further the effective expansion ratio optimally increases. Nomenclature A = nozzle cross-sectional area e = internal energy H = nozzle height h = enthalpy M = Mach number NPR = nozzle pressure ratio, P0 =P a P = pressure P0 = total pressure at the nozzle inlet R = gas constant T = temperature u, v, w = velocity components x = axial direction y = normal direction = ratio of specific heats = flow angle = viscosity. , RL-10B-2 on Delta IV 2nd stage • Plug/aerospike and ED nozzles -requires full aerodynamic model to help determine nozzle boundaries • plug: outer boundary • ED: inner boundary -full aerospike: high performance but cooling difficult. An aerospike nozzle with an expansion ratio of 200:1 to 300:1 can increase the thrust and specific impulse by five to six percent. Fire suppression jet accumulation characteristics exhibited a strong dependence on nozzle pressure, flow rate, and AFFF concentration for the jet flow conditions investigated. Note that is not limited to the nozzle expansion ratio. The nozzle is gimbaled for thrust vector (direction) control. nozzles as follows: a) the nozzle expansion ratio was 1. From that, using equation 9, you can find that for a nozzle with that expansion ratio, the mach number at exit is equal to 3. Experiments were conducted at plenum pressures 30, 40, and 45 psia to ensure the thruster. • Ratio of downstream to upstream pressure >= 0. This is the ratio of the blade velocity and the isentropic gas velocity that would be obtained in its isentropic expansion through the stage pressure ratio. When considering an annular nozzle, the area of the centerbody (A plug) must also be. 7 psia) #: MR is only used for ox/fuel combos. Thrust is calculated according to the relationship: FmvexitPexitPambAexit (1). Experiments were conducted in a facility with 1. Effects: 1. High velocity is achieved through adiabatic expansion of motive steam across a convergent/divergent steam nozzle. N2 - Expansion Deflection nozzles present an attractive proposition as a replacement for conventional nozzles on launch vehicles, due to their reduced length, and altitude compensating. 46 for air and expansion gas. p c / p 1 = ( 2 / (n + 1) ) n / (n - 1) (1) where. Insulating expansion foam ("spray foam") is measured by how much the liquid form of it expands once it's dispensed out of its container (hence the terms "high expansion" and "low expansion" foam). The valve body turns extremely cold to the point ice accumulates. Degree of reaction: It is defined as the ratio of isentropic heat drop in the moving blade. Gas properties at nozzle area ratio can be obtained from a property of the gas called the ratio of specific heat capacities. Matlab code for simulation of performance for hybrid rocket engines. The relation between expansion ratio and pressure ratio can be found from mass conservation and the isentropic relations:. The study is about a supersonic jet flow (perfect expansion), from a C-D Mach 2. 50 NOZZLE THEORY AND THERMODYNAMIC RELATIONS 1) To and P0 designate the stagnation values of the temperature and pressure. The valve body turns extremely cold to the point ice accumulates. Slang The human nose. Fortunately, AeroTech has at its disposal a number of phenolic nozzle "blanks" that were designed with high as-molded. 10 Nominal foam production is the volume of foam produced per time unit, i. 5 MPa with a increment of 0. Net Type Foam Nozzle, Fire Foam Sprinker, Foam Sprinkler manufacturer / supplier in China, offering Net Type Foam Nozzle for Fire Foam System, High Quality Low Noise Oil-Free Air Compressor, Factory Price Water Mist Nozzle for Machine Cooling System and so on. The nominal thrust, in vacuum, of the engine is 116,000 kgf with a specific impulse of 436 seconds, with a 40:1 nozzle expansion ratio. Certain results obtained from a thermodynamic analysis of the ejectors have been confirmed in a wide range of geometrical. 9 Nominal foam expansion ratio is the ratio of the volume of foam to the volume of foam solution from which it was made. [ICEM] Aspect Ratio, Mesh Expansion Factor -- CFD Online Discussion Forums [ Sponsors ]. Note: As expansion ratio is increased, the reach of the stream will be decreased due to the greater. air-aspirating foam nozzles, medium and high expansion devices and compressed air foam systems (CAFS). n Foam expansion ratio approx* 40:1 40:1 40:1 40:1 n Dimensions A 710 mm 710 mm 830 mm 850 mm n Dimensions B 240 mm 240 mm 380 mm 380 mm n Connection 50 DIN PN 16 or 2” ANSI 150 lbs 50 DIN PN 16 or 2” ANSI 150 lbs 65 DIN PN 16 or 2½” ANSI 150 lbs 80 DIN PN 16 or 3” ANSI 150 lbs. Easy of usage. Expansion of Steam at 100 o F. lee march, 1963 ;a company inc huntsville, alabama ots price xerox $ // / o^l microfilm $ /' ^/ technical note r-41 fortran programs for plug nozzle design march, 1963 prepared for advanced propulsion section propulsion and. 1 Table 1 summarizes. The flow separates by the action of a lambda shock, followed by a succession of expansion and compression waves. Both uniform and non-uniform fuel-filling schemes were investigated. Antonyms for nozzle. throat x exit pressure, p throat exit} subsonic throughout} shock in nozzle back pressure} oblique shocks in exit jet} reservoir pressure, p0 sonic pressure. After the throat, the flow area of nozzle has to expand to become the mass flux corresponding to the outlet pressure ratio of design. Design considerations for an optimum nozzle shape with a specific expansion ratio is that the gas flow at the nozzle exit must be uniform and axial for obtaining maximum momentum vector with minimum separation and negligible losses. Furthermore, the AWJ eliminates the problem of thermal distortion or reflectivity due to the material coatings. com All trademarks/service marks referenced on this site are properties of their respective owners. It will use 21. N2 - Expansion Deflection nozzles present an attractive proposition as a replacement for conventional nozzles on launch vehicles, due to their reduced length, and altitude compensating. High-expansion (greater than 250:1 for the ratio of foam volume to initial liquid volume), medium-expansion (20-250:1) and low-expansion (less than 20:1) foams are discussed. If the combustion pressure is 20 atmospheres, the gases undergo an expansion ratio of 20 and this corresponds roughly to a nozzle area ratio of 4. In these relations, A* is the throat area, so if there's an expansion ratio of 5, A/A* is equal to 5. Also, currently in the game the plume of a (vacuum/low pressure optimized) 2nd stage engine expands much less than the plume of the previous (low altitude optimized) stage (at roughly the same high altitude) - as though the game takes nozzle expansion ratio as a big factor in calculating the expansion of the plume. An orifice with diameter D2 = 50 mm is inserted in a pipe with diameter D1 = 114 mm. Certain results obtained from a thermodynamic analysis of the ejectors have been confirmed in a wide range of geometrical. The gas properties have an effect as well. The nominal thrust, in vacuum, of the engine is 116,000 kgf with a specific impulse of 436 seconds, with a 40:1 nozzle expansion ratio. The nozzle expansion ratio of 1. Gas velocities from 2 to 4. Expansion 5 Δpressureavailablefor Turbine Exit Pressure 5 T Combustor Inlet Ambient Pressure pressure available for expansion across Exhaust Nozzle 0 2 1 h W P =Δ Note: 1) Flight Mach = 0 2) P =P Compression 3 Lines of Constant Pressure 2) P t2 = P amb 3) P = power 4) W = mass flow rate 5) h 0 = total enthalpy 2 Compressor Inlet 6 S. And we can set the exit Mach number by setting the area ratio of the exit to the throat. The inlet port carries all structure of the equipment while housing a brass spray nozzle. Answers: 0. nozzle-expansion ratio. The convergent parts of the nozzle are sharp and frictionless. upon the nozzle expansion aree ratio. The lightweight design, which evolved from Pratt's conventional balanced-beam nozzle, allows independent control of nozzle expansion ratio and vectoring capability up to 20 degrees in any direction. All of our foam equipment is designed with safety and ease-of-use in mind for quick fire suppression during any emergency. Of particular note, the ASME standard is limited to pressure ratios greater than the critical pressure ratio and does not cover choked flow through an orifice. Nozzle exit pressure 3 psia. Any help?. Equation #5. This is an easy way to acquire a thicker finished foam blanket. Let us discuss about the Conical nozzle and bell nozzle. Additionally, it produces a foam blanket which provides an insulating barrier between the fuel and air. 25:1 expansion ratio but actual RS-27 A q exit = 30. As shown in. 0, to compare with the circular nozzle. Engine nozzle has an ablative extension that increases it's expansion ratio from 13:1 to 49. Chamber pressure 61. Most large rocket engines use bell-shaped nozzles, which start with a large divergent angle right after the throat, and gradually decrease the angle, ending in a shallow divergent angle at the nozzle exit. The results that are presented in Figures 4, 5 and 6 serve as a useful tool to select those parameters. Learning and information shared in this paper will be useful to anyone interested in using high expansion ratio plugs for wellbore isolation treatments. As an industrial natural-g as burner , the de vice offers ad-vantages over simple nozzles of equi valent capacity. Medium expansion ratio of 30 to 1. 2) to derive the first analytical model capable of providing closed-form solutions for the two-dimensional distributions of the plasma potential, density, and ion Mach number in the expansion region of the nozzle (Fig. Some upper stage engines: Merlin 1D Vacuum (Falcon 9) 165:1. Mach number is the ratio of the gas velocity to the local speed of sound. In both situations, high nozzle expansion ratios (ERs) are created, and shockwaves may be produced from the nozzles. Note that is not limited to the nozzle expansion ratio. Rao's parabolic approximation of a bell nozzle given the. 3 - 4 Reversible adiabatic (isentropic) expansion producing power output. At low altitude the nozzle is overexpanded with exit pressure lower than the ambient pressure, whereas at high altitudes the nozzle is underexpanded with exit pressure higher than ambient pressure. Here it's 0. Nozzle Expansion Ratio. When Outlet pressure p 2 equal to or less than p c, i. The higher the expansion ratio, the more efficient the nozzle is. For the ideal rocket in Problem #1, calculate the mass flow, thrust, specific impulse, and nozzle expansion ratio. Hussaini 2013-2014 decreasing the shock strength (Figure 11. You can change the shape of the diverging section by clicking the area shaded with '+' signs close to the line representing the diverging section. Engine nozzle has an ablative extension that increases it's expansion ratio from 13:1 to 49. The valve body turns extremely cold to the point ice accumulates. It has higher Expansion Ratio – as addition of divergent portion produces steam at higher velocities. What is De-Laval nozzle? De Laval nozzles is a mechanical device used to convert the thermal and pressure energy into useful kinetic energy. Also, the nozzle pressure ratio is generally less than 2 so that expansion ratio variation provides insignificant benefit. The nozzle pressure ratio here is 0. LOW EXPANSION FOAM: Foam aerated to an expansion ratio of between 2 to 1 and 20 to 1. , the ratio of the nozzle outlet static pressure P e to atmospheric pressure. Standard Nozzles. 09063 as per their definition and it would be 1/0. The only existing test that must be passed by a hand-held carbon dioxide extinguisher is. The study is about a supersonic jet flow (perfect expansion), from a C-D Mach 2. In theory, the only important parameter in rocket nozzle design is the expansion area ratio (e), or the ratio of exit area (A exit) to throat area (A throat). This gives us an expansion ratio of 3. In this paper, the influence of the circular and the rectangular cross-section nozzle are taken into account, considering the CFD and experiments. Note: As expansion ratio is increased, the reach of the stream will be decreased due to the greater. As the expansion ratio remains above its critical value, the fl ow stays below the critical fl ow. By definition an ideal nozzle expands the throat flow isentropically and produces a parallel uniform exit flow at a prescribed exit Mach number, \(M_2\) , or ε. Most large rocket engines use bell-shaped nozzles, which start with a large divergent angle right after the throat, and gradually decrease the angle, ending in a shallow divergent angle at the nozzle exit. CFD: Super Sonic Diverging Rocket Nozzle CFD Solver: Ansys Fluent Chamber Pressure: 50 bar Chamber Temperature: 1200 K Nozzle Angle: 15 deg Nozzle Expansion Ratio: 9. with an increase of the pressure ratio; this ratio increases when the value of the chamber pressure Pl increases or when the exit pressure P2 decreases, corre- sponding to high altitude designs. Mostly class B fires Medium expansion- ratio of 20-1 to 200-1 through hydraulic operated nozzle 30-1 and 55-1 for hazardous materials High expansion - ratio of 200-1 to 1000-1 typically confined spaces. ht8 = h8 + V8 ^2 / 2 / nn. The ratio, for a perfect gas, remains constant throughout the expansion process. 15 synonyms for nozzle: nose, proboscis, beak, snoot, schnoz, schnozzle, snout, nose, hooter, schnoz. 4 and then decreased gradually to 8. This lightweight aluminum foam nozzle features a durable Viper ball valve and is available in 60 or 90 gpm. 3 times the nozzle exit diameter in the base region. Additionally, it produces a foam blanket which provides an insulating barrier between the fuel and air. neptunium (Np) [nep-too´ne-um] a chemical element, atomic number 93, atomic weight 237. Low expansion nozzles (expansion up to 20:1) Low expansion nozzles produce wet or fluid foam that is most effectively used for exposure protection, direct attack and overhaul. single-expansion ramp nozzle (SERN), a linear expansion nozzle, where the gas pressure transfers work only on one side and which could be described as a single-sided aerospike nozzle. 202 Elements of Heat Engines Vol. download the script: Nozzle and Diffuser For more analyses of compressible flow through nozzles and diffusers, click the topic "Gas Dynamics" please: Gas Dynamics A nozzle is a device which accelerates fluid. The nozzle expansion ratio of 1. This article provides calculation methods for correlating design, flow rate and pressure loss as a fluid passes through a nozzle or orifice. • Medium expansion nozzles. For this reason, we restudied the nozzle design process, hoping that the engine performance can be significantly improved only by the nozzle design. The area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied are 2. Any help?. Having the higher expansion ratio will cause the foam blanket to last longer or not break down as fast, preventing the need to reapply as often and reducing the amount of water and concentrate needed. Note that said fire fighting substance represents combine foam jet with low expansion ratio of 7 to 20 and medium expansion ratio. Certain results obtained from a thermodynamic analysis of the ejectors have been confirmed in a wide range of geometrical. full text of "fortran programs for plug nozzle design" see other formats technical note r-41 fortran programs for plug nozzle design f^fi5^ c-^^ ^ f^^^ prepared by c. This can cause the flow to accelerate as it passes into the nozzle (Helley and Smith, 1971). Using a k-factorial statistic test, the performance of the aerospike nozzle will be compared to the control (conventional) nozzle to find if a statistically significant difference in maximum altitude can be achieved with. According to Spaceflight 101, the chamber pressure is the same, but the expansion ratio (throat area to end-of-nozzle area) is 7 times larger in the vacuum variant, which (if correct) implies about 2. as a result of the expansion of the exhust we see a drop in pressure from 37 atm to 1 atm, a drop of ~97. The nozzle cone exit diameter (De) can now be calculated. Each of these allows the supersonic flow to adapt to the ambient pressure by expanding or contracting, thereby changing the exit ratio so that it is at (or near. 2:1 Turbine exhaust is ducted through a swiveling nozzle to provide Stage II roll control. It can be easily removed in seconds for a water-only or non-aspirated stream. The study recommended that conical nozzle be used at sea-level and that the contour nozzle be used at higher altitudes since for a given nozzle length, greater expansion ratio is required at higher altitudes [5]. Axial velocity distribution on the nozzle for different NPRs At low Nozzle pressure ratios (NPR 2), effect of cowl is least significant. This study reveals that the addition of a nozzle to the PDE combustor has the. The variable expansion ratio geometry did not provide the expected improvements in discharge coefficient and system thrust ratio throughout the flight envelope of typical a supersonic aircraft. EXPANSION RATE: Volume of finished foam divided by the volume of foam solution used to create the finished foam; i. 30 and R = 66 ft-lbf/lbm- R at a chamber pressure of 300 psia and a constant chamber temperature of 5300 R against a back atmospheric pressure of 10 psia. (Proportioner) and the Low Expansion Foam Nozzle. The nozzle is gimbaled for thrust vector (direction) control. For this reason, we restudied the nozzle design process, hoping that the engine performance can be significantly improved only by the nozzle design. Nozzle efficiency: It is the ratio of useful heat drop to the isentropic heat drop. An early design for the F-1 thrust chamber had a completely regeneratively-cooled nozzle, all the way to the 16:1 expansion plane, which incorporated two bifurcation joints. rapidly with pressure decrease. Rotating the nozzle shaper forward to straight stream (clockwise), will produce lower expansion ratios, but with increased stream reach. Expansion ratios are broken into three categories: low, medium. Discharge coefficient. • When the number of full range pressure cycles is greater than 7000 and the nozzle is subject to external loads. 648 expansion ratio. Design of a specific nozzle requires the following data: throat diameter D t, axial length of the nozzle from throat to exit plane L n (or the desired fractional length, L f, based on a 15-degree conical nozzle), expansion ratio , initial wall angle of the parabola n, and nozzle exit wall angle e. Insulating expansion foam ("spray foam") is measured by how much the liquid form of it expands once it's dispensed out of its container (hence the terms "high expansion" and "low expansion" foam). Rocket Nozzle Design: Optimizing Expansion for Maximum Thrust. At high altitude the flaps are closed and sealed such that the multiple engines have a single expansion nozzle 12 feet or more in diameter giving the maximum possible expansion ratio. During 1973-76, extensive calibration testing of the Helley-Smith sampler was conducted in the field. The gas properties have an effect as well. High velocity is achieved through adiabatic expansion of motive steam across a convergent/divergent steam nozzle. nozzle synonyms, nozzle pronunciation, nozzle translation, English dictionary definition of nozzle. In this article series, we'll break the foam family into two primary branches: One is detergent-based, and the other is protein. Expansion factor Y for Venturi tubes and nozzles can be calculated as follows (ISO 5167):. Thanks not sure if its 752 m/s or 649 m/s for the answer. 55 Notes: An additional center segment was added to the current 4-segment RSRB, along with a new nozzle to handle the increased mass flow rate. Answers: 0. The diameter ratio can be calculated to. For these reasons, fixed convergent nozzles are well suited to subsonic applications. The expansion ratio, nozzle cross sectional area at exit divided by area at throat, would be 6. Nozzle exit pressure 3 psia. Active control in the form of micro jets are used as an active control of 1 mm orifice diameter located at 900 intervals along a pitch circle diameter of 1. Since both engines have the same throat of 226mm (8. Results show that the extent of influence of the expansion ratio depends on the densimetric Froude number, grain size of the bed material and tailwater conditions. For turbines, the value of ηT is typically 0. p c / p 1 = ( 2 / (n + 1) ) n / (n - 1) (1) where. Nozzles and orifices are often used to deliberately reduce pressure, restrict flow or to measure flow rate. Bronze, Aluminum. In nozzle design: all the calculations are. If, however, you wish to turn this into a theoretical. I've been looking, and find many references to 'very high temperatures' and lots of other characteristics of the rocket engine. Considering a rocket nozzle, we can set the mass flow rate by setting the area of the throat. The expansion ratio also allows the nozzle designer to set the exit pressure. , Norfolk, VA 23529, United States b KosKom Technologies LLC, Menasha, WI 54952, United States c University of Wisconsin - Platteville, Mechanical and Industrial Engineering Department, Menasha, WI 54942, United States. Answers: 0. This position will produce the maximum expansion ratio (approximately 8-1). 4 and a downstream contour area ratio 1:64. Gas velocities from 2 to 4. Amongst the variations are: a) Extendable nozzles. 4 and then decreased gradually to 8. 09063 as per their definition and it would be 1/0. These tools are standard equipment on Engine Companies. For about $5,000 to $10,000, foam rigs can be outfitted with a “fault-interruption ratio” (when the mix goes off ratio, the rig shuts down) and a temperature monitor and will also produce printouts as proof of proper ratio. Fluid is blowing thrue a nozzle at the bottom of the plenum and impinges to the plate. 3 kN of axial thrust at an expansion ratio of ε = 2,941. An aerospike nozzle expands the rocket motor exhaust gases around a center body rather than internally in the exit cone of a conventional nozzle. The selection of an optimum nozzle shape for a given expansion ratio is generally influenced by the following design considerations and goals: (1) uniform, parallel, axial gas flow at the nozzle exit for maximum momentum vector, (2) minimum separation and turbulence losses within the nozzle, (3) shortest possible nozzle length for minimum space. 25 mm is attached to the rear of the nozzle assembly with a rubber “O. In all cases, the ratio of inlet total pressure to exit static pressure, which is called nozzle pressure ratio, are set to be 7. 2) Subsonic and Supersonic Nozzles 3) Rocket C-D Nozzles 4) Generation of thrust 5) Over Expanded and Under Expanded Nozzles I hope you take away some new concepts in fluid mechanics after this video. The optimal design of traditional bell-type nozzles for given operating conditions (i. The nominal thrust, in vacuum, of the engine is 116,000 kgf with a specific impulse of 436 seconds, with a 40:1 nozzle expansion ratio. The Mach number at the nozzle exit is given by a perfect gas expansion expression P c is the pressure in the combustion chamber and P atm is atmospheric pressure, or 14. Keywords- Nozzle expansion Ratio, Ansys, Air fuel Ratio, Dynamo meter, Back pressure Draw the half portion of the CD nozzle with the specified dimensions given in Table 1. TIP, EXPANSION (part #LX-MX-95) Lightweight and easy to use tip attachment. Thermal engineering by rk rajput chapter 18 STEAM FLOW THROUGH NOZZLE8 The steam now through the noule may be assumed as adiabatic flow alnoe during the expansion of atoun in nozzle neithar any heat is supplied nor rejected, work, however, is per formed hy Increasing the kinetic energy of the steam. • Low expansion nozzles (expansion up to 20:1) Low expansion nozzles produce wet or fluid foam that is most effectively used for exposure protection, direct attack and overhaul. 46 for air and expansion gas. Design considerations for an optimum nozzle shape with a specific expansion ratio is that the gas flow at the nozzle exit must be uniform and axial for obtaining maximum momentum vector with minimum separation and negligible losses. (See Appendix 6. 5645; 3470 ft/sec; 14; and 8570 ft/sec. MEDIUM EXPANSION FOAM: Expansion ratio between 20 to 1 and 200 to 1. The nozzle converts the slow moving, high pressure, high temperature gas in the combustion chamber into high velocity gas of lower pressure and temperature. An orifice with diameter D2 = 50 mm is inserted in a pipe with diameter D1 = 114 mm. If the steam floe rate is 1 kg/s and the initial velocity of steam is negligible, find the minimum area of the nozzle. 09063 as per their definition and it would be 1/0. The highest possible velocity of argon gas at the nozzle exit is? Someone that is good at solving these problems, need help. If, for some reason, the designer provides a nozzle area less than that needed for complete expansion, the exhaust gases emerge from the nozzle exit at greater than ambient pressure. Synonyms for Nozzles in Free Thesaurus. Linear-walled nozzle. Equation #5. Nozzle exit pressure 3 psia. The expansion ratio is the amount of finished expanded foam that will be produced using the correct nozzle. Zinc plated inlet connection; AISI 304 / AISI 316 stainless steel inlet connection; UNI / DIN, ANSI / ASA flanged inlet connection; Flow rate 233lpm, 378 lpm; Expansion ratio 816:1, 820:1. 62 and the diameter of throat was 88. methane dual expander aerospike nozzle rocket engine. Size and expansion ratio analysis of micro nozzle gas flow☆ Omer Sana, Ilhan Bayraktarb, Tuba Bayraktarc,⁎ a Old Dominion University, Aerospace Eng. The first is an attachment for the typical fog nozzle. 5 as the nozzle L/D was increased to 10. Expansion factor Y for Venturi tubes and nozzles can be calculated as follows (ISO 5167):. As the ambient pressure is reduced further the effective expansion ratio optimally increases. LTN Long Throw Nozzles with flow rates: 900 - 3300 lpm Foam Expansion Ratio: Typically. I'm talking expansion nozzles like the valve on a SCUBA tank for example. Ethylene ethyl acrylate (EEA) Ethylene vinyl acetate (EVA). The all-axis gimbaling capability is 8 degrees. Expand, slowly with temperature rise, or. 0 mm and an exit diameter of 7. Converging-Diverging Nozzle The behaviour is governed by the ratio of back pressure to total pressure, p B expansion shocks downstream/ p 0, and the area expansion ratio A exit / A throat. concluded that entrainment ratio and coefficient of performance of the ejector increase with increase in expansion ratio and area ratio and also increase with decrease in compression ratio. The expansion ratio of the extrusion‐cooked starch increased from 4. The nominal thrust, in vacuum, of the engine is 116,000 kgf with a specific impulse of 436 seconds, with a 40:1 nozzle expansion ratio. Initially, during launch and low subsonic operation, all four divergent flaps would fixed in a closed position thus providing a low nozzle expansion ratio. The rangeability is 4 to 1. The inability to control the throat gap leads to using multiple thrusters which are then expanded over a ramp (in the linear case) or annular plug nozzle. The high expansion foam generator are suitable for installation in warehouse, flammable liquid stores, tunnels and marine engine and pump rooms. For the ideal rocket in Problem #1, calculate the mass flow, thrust, specific impulse, and nozzle expansion ratio. The required upstream diameter is 10 to 30. Average molecular mass 21. The study recommended that conical nozzle be used at sea-level and that the contour nozzle be used at higher altitudes since for a given nozzle length, greater expansion ratio is required at higher altitudes [5]. 62 and the diameter of throat was 88. Nozzle Expansion Ratio. Used on Ariane 5 launch vehicle. For example, if an air-aspirating nozzle draws in nine units of air for each unit of foam solution discharged, this equates to a 10:1 expansion ratio of finished foam to foam solution. The fluid does not contract any further as it leaves the nozzle and the pressure loss created is. Mach number Nm is the ratio of the gas velocity to the local speed of sound. • When the number of full range pressure cycles is greater than 7000 and the nozzle is subject to external loads. As air pressure decreases with altitude, the exhaust pressure gradually pushes the flaps closed. Fortunately, AeroTech has at its disposal a number of phenolic nozzle “blanks” that were designed with high as-molded. that the flow fills the nozzle and is supersonic to the exit. But this situation produces over-expansion of the flow, resulting in significant thrust loss. The objective of this work is to develop guidelines to identify the optimum nozzle geometry that maximizes critical pressure ratio while minimizing pressure drop across the nozzle. However, the flow is deflected by a plug, or centerbody, that forces the gases away from the. Under these conditions, the nozzle is said to be choked and the nozzle outlet pressure remains at the critical pressure. 92 to at least 0. 5 and for a range of nozzle pressure ratios. Antonyms for nozzle. This position will produce the maximum expansion ratio (approximately 8-1). The foam with expansion ratio between 1:2 and 1:20 is called low expansion foam. The thrust chamber was tubular-walled and regeneratively fuel-cooled to the 10:1 expansion ratio plane. Fixing all other variables (primarily the chamber pressure), there exists only one such ratio that optimizes overall system performance for a given altitude (or ambient pressure). MID-EXPANSION – Expansion ratio from 20:1 to 200:1. Design Mach number, number of expansion waves, ratio of specific heat are supplied by user. 0%, provides for longer surface wetting with reduced risk of ignition/re-ignition. full text of "fortran programs for plug nozzle design" see other formats technical note r-41 fortran programs for plug nozzle design f^fi5^ c-^^ ^ f^^^ prepared by c. Expansion ratios are broken into three categories: low, medium. "We developed a ton of data on thrust vectoring in F-15 S/MTD and the F-22 Advanced Tactical Fighter program, both of which had two-dimensional. Core stage engines with an operation time of up to 10 minutes feature a medium-range expansion ratio, whereas upper stage engines. Based on the success of the pilot project, the technique will be deployed in all applicable 7" cased wells. By definition an ideal nozzle expands the throat flow isentropically and produces a parallel uniform exit flow at a prescribed exit Mach number, \(M_2\) , or ε. A vehicle using an aerospike nozzle also saves 25-30% more fuel at low altitudes. An a erospike nozzle with an expansion ratio of 200:1 to 300:1 can i ncrease the thrust and specific impulse by five to six percent. Nozzle flow chemical kinetics: Re-association of relatively unstable (high positive heat of formation) molecules as gas cools in the nozzle. If I change the COL to 2. air-aspirating foam nozzles, medium and high expansion devices and compressed air foam systems (CAFS). 5 and for a range of nozzle pressure ratios. The diameter ratio can be calculated to. 46 for air and expansion gas. The nozzle efficiency is greatly affected by the nozzle contour. For verified definitions visit AcronymFinder. The selection of an optimum nozzle shape for a given expansion ratio is generally influenced by the following design considerations and goals: (1) uniform, parallel, axial gas flow at the nozzle exit for maximum momentum vector, (2) minimum separation and turbulence losses within the nozzle, (3) shortest possible nozzle length for minimum space. Expansion factor Y for Venturi tubes and nozzles can be calculated as follows (ISO 5167):. Solid propellant rocket stage. 2b), until eventually the isentropic case, curve f, is reached If the receiver pressure is below the third critical point, an expansion takes place outside the nozzle. I'm talking expansion nozzles like the valve on a SCUBA tank for example. For these reasons, fixed convergent nozzles are well suited to subsonic applications. This research consists of a base line test of the factory nozzle, as well as testing of three 15-degree conical nozzles with different expansion ratios. Synonyms for Nozzles in Free Thesaurus. Engine nozzle has an ablative extension that increases it's expansion ratio from 13:1 to 49. In all cases, the ratio of inlet total pressure to exit static pressure, which is called nozzle pressure ratio, are set to be 7. Each of these allows the supersonic flow to adapt to the ambient pressure by expanding or contracting, thereby changing the exit ratio so that it is at (or near) optimal exit pressure for the corresponding altitude. Some upper stage engines: Merlin 1D Vacuum (Falcon 9) 165:1. 2 delivers gases at k = 1. The gas properties have an effect as well. The nozzle expansion ratio of each booster beginning with the STS-8 mission is 7-to-79. 0338 if we follow your definition. [AR] Parabolic Nozzle Approximation Function. nozzle: Shouldn't all hydrants be equipped with hoses and nozzles?, BIB VALVE, PNEUMATIC WEIGHING SYSTEM, NOZZLE-MIX GAS BURNER, NOZZLE-EXPANSION RATIO, NOZZLE EXIT AREA. Nozzles synonyms, Nozzles pronunciation, Nozzles translation, English dictionary definition of Nozzles. American Institute of Aeronautics and Astronautics 12700 Sunrise Valley Drive, Suite 200 Reston, VA 20191-5807 703. 5 shows the actual expansion of steam through nozzle. However, construction of the valve that holds high pressure on one side, and facing low pressure on the other, determines the way refrigerant liquid expands. The specific impulse would be 151 s (1480 N·s/kg). It is the shape of this nozzle that is key to the expansion process. The all-axis gimbaling capability is 8 degrees. There was a great reduction for the T g by HP-DSC test and decrease for the viscosity by high pressure capillary test, which indicated that it is feasible for PSU to foam by supercritical CO 2. Fire suppression jet accumulation characteristics exhibited a strong dependence on nozzle pressure, flow rate, and AFFF concentration for the jet flow conditions investigated. Segment of a radial compressor and vaned diffuser plate Vanes shorten the flow path through the diffuser, reducing frictional losses and controlling the radial velocity component of the gas. The expansion ratio of the bell nozzle being compared to the aerospike nozzle. Coefficient of nozzle: It is the ratio of actual enthalpy drop to isentropic enthalpy drop. The study is about a supersonic jet flow (perfect expansion), from a C-D Mach 2. If the nozzle expansion ratio was reduced to 1. 30 and R = 66 ft-lbf/lbm- R at a chamber pressure of 300 psia and a constant chamber temperature of 5300 R against a back atmospheric pressure of 10 psia. - Maximum resistance to internal corrosion by foam compounds and to weather conditions. The worksheet output image for this group is given in Figure 1. ) is a typical value for injection of 2. In all cases, the ratio of inlet total pressure to exit static pressure, which is called nozzle pressure ratio, are set to be 7. Epoxy, castings resins & compounds, unfilled. Baseline operation was at a mixture ratio of 5. Reference: Rocket Propulsion Elements, 8th Edition, Equation 3-25. A perfectly expanded nozzle is only possible using a variable throat area or variable exit area nozzle to counteract the ambient pressure decrease with gaining altitude. The flow of steam through nozzles may be takenas adiabatic expansion. Lightweight nozzles are better for high power-to-weight ratio, higher wall temperatures allows for higher exhaust velocity and less regenerative cooling requirements, while lower expansion ratios allow for shorter, lighter nozzles. The results are compared with available experimental data in a nozzle of the same geometry. Determine the critical pressure ratio, the gas velocity at the throat, the expansion area ratio, and the theoretical nozzle exit velocity. 1 MPa or 1 atm), temperature of 502 K at the nozzle exit. ID PVC pipelines and a 30 ft. Reference: Rocket Propulsion Elements, 8th Edition, Equation 3-25. A comparison is made between momentum balance and pressure integral methods of calculating the ideal vacuum thrust coefficient, and the results used to examine how corrections should be made for nozzle divergence, skin friction and two-phase flow to obtain the real thrust coefficient of the motor U~Y~j-4. Nozzle Outlet Velocity Equation. 15 synonyms for nozzle: nose, proboscis, beak, snoot, schnoz, schnozzle, snout, nose, hooter, schnoz. Buy the C & S Supply Viper Foam Nozzle from eDarley. Nomenclature A = nozzle cross-sectional area e = internal energy H = nozzle height h = enthalpy M = Mach number NPR = nozzle pressure ratio, P0 =P a P = pressure P0 = total pressure at the nozzle inlet R = gas constant T = temperature u, v, w. Antonyms for nozzle. However, efficiency drops off rather quickly as nozzle opening is reduced or increased from a mid-vane opening position, Figure 3 [2641]. 2 expansion ratio is used for RSRMV Throat diameter, exit diameter, and length all increased in order to control the volume and velocity of the gases that are generated in the RSRMV design 20. Low expansion nozzles (expansion up to 20:1) Low expansion nozzles produce wet or fluid foam that is most effectively used for exposure protection, direct attack and overhaul. According Equation 4 should following a mass flow rate fall. This trend is plotted in Figure 3. 1 bar) and greater Application ANSUL KR-S/M dual-expansion foam handline nozzles can be. Convergent – Divergent (c-d nozzle) : The nozzle which converges to throat and diverges afterwards. Design the nozzle expansion ratio using the compressible flow equations. If you want to go beyond the critical expansion ratio in a converging diverging nozzle, the. The ratio of the nozzle total to static pressure ratio is called the nozzle pressure ratio NPR. The pressure loss is medium. Thermal expansion relates with the expansion and contraction of particles in a substance function of temperature. At high altitude the flaps are closed and sealed such that the multiple engines have a single expansion nozzle 12 feet or more in diameter giving the maximum possible expansion ratio. I can envision the corrugated nozzle described above resuming its bell shape, and I can envision a similar folding around the nozzle circumferentially to reduce its length but I'm at a. p c = critical pressure (Pa) p 1 = inlet pressure (Pa) n = index of isentropic expansion or compression - or polytropic constant. Worked Example #3 Example #4 - Calculate nozzle flow exit velocity for a rocket motor operating at 68 atmospheres chamber pressure, expanding to ambient air, using KNSB as propellant. For both gradual-expansion and minimum-length nozzles, the flow can be divided into simple and non-simple regions. 1 Notable is the low expansion ratio of booster engines due to the comparable short duration time. Depending on the foam manufacturer, you will see expansion rates ranging from 7:1 clear up to 15:1. Effects: 1. Also, currently in the game the plume of a (vacuum/low pressure optimized) 2nd stage engine expands much less than the plume of the previous (low altitude optimized) stage (at roughly the same high altitude) - as though the game takes nozzle expansion ratio as a big factor in calculating the expansion of the plume. The inability to control the throat gap leads to using multiple thrusters which are then expanded over a ramp (in the linear case) or annular plug nozzle. P out = H/s = m c p (T 3-T 4) 4 - 1 Constant pressure cooling back to the original state requiring heat removal. The nozzle is gimbaled for thrust vector (direction) control. The purpose of this research is to develop new nozzles for the HYDROSTM thruster, a pulsed chemical thruster, to improve the current flight performance. 15 synonyms for nozzle: nose, proboscis, beak, snoot, schnoz, schnozzle, snout, nose, hooter, schnoz. Assume the intersection of the centerline and the exit plane of the nozzle is the origin of our coordinate system. And from the Mach number and temperature we can determine. Expansion of Steam at 100 o F. Medium Expansion Foam Tubes • Designed to quickly attach to pattern bumper of Crestar nozzles • Ideal for use with all types of foam • Constructed of stainless steel for extended life • Foam ratio up to 50:1. An a erospike nozzle with an expansion ratio of 200:1 to 300:1 can i ncrease the thrust and specific impulse by five to six percent. Hussaini 2013-2014 nozzle outlet and further reduction of the receiver pressure will have no effect on the flow conditions inside the nozzle. sea level=14. In this study, taking the 750N engine as an example, we made a simple and effective modification on Rao’s method. 5 and 2 times, giving a highly collimated hypersonic exhaust jet. Rao's parabolic approximation of a bell nozzle given the. If you do know the expansion ratio of your nozzle, or nozzle attachment, this factor can be added. MID-EXPANSION - Expansion ratio from 20:1 to 200:1. download the script: Nozzle and Diffuser For more analyses of compressible flow through nozzles and diffusers, click the topic "Gas Dynamics" please: Gas Dynamics A nozzle is a device which accelerates fluid. With a variety of brands to choose from, you can find the precise foam firefighting equipment for your department's needs. Copper, Beryllium 25. The ratio between critical pressure and initial pressure for a nozzle can expressed as. instability of the separated flow in convergent–divergent nozzles of moderate expansion ratio. Results are reported from a recent study of the effects of Space Shuttle Main Engine expansion ratio modifications, in the cases of both single-stage and two-stage systems. [ICEM] Aspect Ratio, Mesh Expansion Factor -- CFD Online Discussion Forums [ Sponsors ]. These shocks reduce turbine efficiency and can cause high cycle fatigue (HCF) damage to the downstream rotor blades. Fixed or automatic fog nozzles, air aspirating attachments and high-expansion foam generators introduce different volumes of air into foam solution to create various finished-foam blanket qualities. then the ratio is called critical pressure ratio. The actual length of the nozzle is up to the creator, but the nozzle I created ended with a total length of 2. Also, the nozzle pressure ratio is generally less than 2 so that expansion ratio variation provides insignificant benefit. Downstream of the nozzle exit, oblique shock cells are formed. 5, oxidizer to fuel, with the capability to operate at mixture ratios of 5. Worked Example #3 Example #4 - Calculate nozzle flow exit velocity for a rocket motor operating at 68 atmospheres chamber pressure, expanding to ambient air, using KNSB as propellant. NASA CEA online was used to calculate the ratio of specific heats (γ) at the throat (γ*t) and at the nozzle exit (γe), the temperature in the combustion chamber (Tc), the molar mass of the products at the exit (M), and the pressure at the exit with the expansion ratio of 16 (Pe*), across pressures from 8. UNIT - 4 Flow Through Nozzles Velocity and heat drop, Mass discharge through a nozzle, Critical pressure ratio and its significance, Effect of friction, Nozzle efficiency, Supersaturated flow, Design pressure ratio. CFD: Super Sonic Diverging Rocket Nozzle CFD Solver: Ansys Fluent Chamber Pressure: 50 bar Chamber Temperature: 1200 K Nozzle Angle: 15 deg Nozzle Expansion Ratio: 9. Each of these allows the supersonic flow to adapt to the ambient pressure by expanding or contracting, thereby changing the exit ratio so that it is at (or near. 10 Chamber Pressure Nominal 9 bar Inlet Pressure Range 10 … 23 bar Throat Diameter (inner) 2. Synonyms for nozzle in Free Thesaurus. A comparison is made between momentum balance and pressure integral methods of calculating the ideal vacuum thrust coefficient, and the results used to examine how corrections should be made for nozzle divergence, skin friction and two-phase flow to obtain the real thrust coefficient of the motor U~Y~j-4. Finally, suggestions for when, where, and how to apply foams for vapor control are presented. Theoretical calculations of specific impulse to determine the separate effects of increasing the combustion-chamber pressure and the nozzle expansion ratio on the performance of the propellants, hydrogen-fluorine, hydrogen-oxygen, ammonia-fluorine and AN-F-58 fuel - white fuming nitric acid (95 percent). Furthermore, the AWJ eliminates the problem of thermal distortion or reflectivity due to the material coatings. Bronze, Aluminum. 46 for air and expansion gas. The nozzle converts the slow moving, high pressure, high temperature gas in the combustion chamber into high velocity gas of lower pressure and temperature. 2:1 Turbine exhaust is ducted through a swiveling nozzle to provide Stage II roll control. High velocity is achieved through adiabatic expansion of motive steam across a convergent/divergent steam nozzle. American Institute of Aeronautics and Astronautics 12700 Sunrise Valley Drive, Suite 200 Reston, VA 20191-5807 703. Mach number Nm is the ratio of the gas velocity to the local speed of sound. The inability to control the throat gap leads to using multiple thrusters which are then expanded over a ramp (in the linear case) or annular plug nozzle. 4 and then decreased gradually to 8. For these reasons, fixed convergent nozzles are well suited to subsonic applications. The Arnhem and Helley-Smith samplers have an expansion ratio (ratio of exit area to entrance area) of 3. Example #3 - Calculate nozzle Optimum Expansion ratio for a rocket motor operating at 65 atmospheres chamber pressure expanding to ambient air. As an industrial natural-g as burner , the de vice offers ad-vantages over simple nozzles of equi valent capacity. Using the isentropic relations , we can determine the pressure and temperature at the exit of the nozzle. Segment of a radial compressor and vaned diffuser plate Vanes shorten the flow path through the diffuser, reducing frictional losses and controlling the radial velocity component of the gas. Nozzle efficiency: It is the ratio of useful heat drop to the isentropic heat drop. My question is how is this a perfect expansion ? wouldn't perfect expansion ratio be p/p0=1=po/p?. engine performance. Bronze, Aluminum. 1 Notable is the low expansion ratio of booster engines due to the comparable short duration time. ID PVC pipelines and a 30 ft. Change in fluid head. The flow separates by the action of a lambda shock, followed by a succession of expansion and compression waves. The expansion upto throat is taken to be isentropic. Each nozzle has a carbon cloth liner that erodes and chars during firing. The valve body turns extremely cold to the point ice accumulates. ) The relatively stagnant region in the center of the nozzle can possibly be used for installation of gas generators, turbopumps, tanks, auxiliary equipment, and turbine gas discharges. LTN Long Throw Nozzles with flow rates: 900 - 3300 lpm Foam Expansion Ratio: Typically. For example, a Task Force Tip (TFT) will aerate, or expand, the foam solution at the nozzle by a factor of 4 (4:1). 5 shows the actual expansion of steam through nozzle. m generates characteristic net and the contour of nozzle. The area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied are 2. performance of plug nozzles is then compared to that of linear-walled nozzles for equal pressure ratios, Reynolds numbers, and expansion ratios. Optimum expansion occurs when the pressure of the exhaust gasses at the exit plane of the nozzle is equal to the ambient pressure. Assume the intersection of the centerline and the exit plane of the nozzle is the origin of our coordinate system. Nozzle Angle: 15 deg Nozzle Expansion Ratio: 9. Rockets depend for their action on Newton's Third Law of Motion that: "For every action there is an equal and opposite reaction. if the fluid is steam, then the nozzle is called as Steam nozzle. The actual length of the nozzle is up to the creator, but the nozzle I created ended with a total length of 2. An a erospike nozzle with an expansion ratio of 200:1 to 300:1 can i ncrease the thrust and specific impulse by five to six percent. The article presents the results from experimental investigations of supersonic gas ejectors equipped with a conical mixing chamber having different lengths carried out for a number of values of the basic geometrical parameter and the active gas nozzle expansion ratio. Active control in the form of micro jets are used as an active control of 1 mm orifice diameter located at 900 intervals along a pitch circle diameter of 1. Looking for nozzle-expansion ratio? Find out information about nozzle-expansion ratio. If a manufacturer tells you a specific expansion ratio for their nozzle ask them to provide you with the brand of foam, the expansion rate of the foam (low, medium, or high), and the conditions under which the tests results were obtained. However, the flow is deflected by a plug, or centerbody, that forces the gases away from the. That means, velocity of…. Bell nozzle lengths beyond approximately 80% do not significantly contribute to performance, especially when weight penalties are considered. The nozzle expansion ratio of each booster beginning with the STS-8 mission is 7-to-79. , Norfolk, VA 23529, United States b KosKom Technologies LLC, Menasha, WI 54952, United States c University of Wisconsin - Platteville, Mechanical and Industrial Engineering Department, Menasha, WI 54942, United States. High-expansion (greater than 250:1 for the ratio of foam volume to initial liquid volume), medium-expansion (20-250:1) and low-expansion (less than 20:1) foams are discussed. The nozzle efficiency is greatly affected by the nozzle contour. As the expansion ratio remains above its critical value, the fl ow stays below the critical fl ow. Also, the nozzle pressure ratio is generally less than 2 so that expansion ratio variation provides insignificant benefit.