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N2O4/A50 IspVac = 313.184 sec MRcore = 1.87985 MRthruster = 1.59787 Rt = 5.97069 in At = 111.995 in**2 Pc = 100 psia Fvac = 20500 lbf |
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Apollo SPS | |
| RocketIsp version 0.1.8 | Friday, Dec 04, 2020 at 04:33PM |
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N2O4/A50 IspVac = 313.184 sec MRcore = 1.87985 MRthruster = 1.59787 Rt = 5.97069 in At = 111.995 in**2 Pc = 100 psia Fvac = 20500 lbf |
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| Geometry |
|---|
| Input | |||
|---|---|---|---|
| Parameter = | Value | Alt Value | Description |
| cham_conv_deg = | 30.00 deg | half angle of conical convergent section | |
| CR = | 2.5 | chamber contraction ratio (Ainj / Athroat) | |
| eps = | 62.5 | nozzle area ratio (Aexit / Athroat) | |
| LchamberInp = | None in | user input value of chamber length (will override all other entries) | |
| LchmMin = | 2.000 in |
5.080 cm 0.167 ft |
minimum chamber length (will override LchmOvrDt) |
| LchmOvrDt = | 3.1 | ratio of chamber length to throat diameter (Lcham / Dthrt) | |
| LnozInp = | None in | user input nozzle length (will override pcentBell) | |
| pcentBell = | 72.3 | nozzle percent bell (Lnoz / L_15deg_cone) | |
| RchmConv = | 1 | radius of curvature at start of convergent section (Rconv / Rthrt) | |
| RdwnThroat = | 1 | radius of curvature just downstream of throat (Rdownstream / Rthrt) | |
| Rthrt = | 5.971 in |
15.166 cm 0.498 ft |
throat radius |
| RupThroat = | 1.5 | radius of curvature just upstream of throat (Rupstream / Rthrt) | |
| Output | |||
|---|---|---|---|
| Parameter = | Value | Alt Value | Description |
| Ainj = | 279.987 in**2 | 1806.367 cm**2 | area of injector |
| At = | 111.995 in**2 | 722.547 cm**2 | throat area |
| Dexit = | 94.405 in |
239.788 cm 7.867 ft |
nozzle exit diameter |
| Dinj = | 18.881 in |
47.958 cm 1.573 ft |
diameter of injector |
| Dthrt = | 11.941 in |
30.331 cm 0.995 ft |
throat diameter |
| entrance_angle = | 36.79 deg | nozzle initial expansion angle | |
| exit_angle = | 9.34 deg | nozzle exit angle | |
| Lcham_conv = | 10.009 in |
25.424 cm 0.834 ft |
length of convergent section of chamber |
| Lcham_cyl = | 27.009 in |
68.602 cm 2.251 ft |
length of cylindrical section of chamber |
| Lnoz = | 111.254 in |
282.586 cm 9.271 ft |
nozzle length |
| Ltotal = | 148.273 in |
376.613 cm 12.356 ft |
nozzle + chamber length |
| Rinj = | 9.440 in |
23.979 cm 0.787 ft |
radius of injector |
| Vcham = | 9460.8 in**3 | 155034.6 cm**3 | approximate chamber volume |
| N2O4/A50 Core Stream Tube |
|---|
| Input | |||
|---|---|---|---|
| Parameter = | Value | Alt Value | Description |
| adjCstarODE = | 1 | multiplier on NASA CEA code value of cstar ODE (default is 1.0) | |
| adjIspIdeal = | 1 | multiplier on NASA CEA code value of Isp ODE (default is 1.0) | |
| CdThroat = | 0.990299 |
Cd of throat (RocketThruster object may override) (MLP fit) |
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| fuelName = | A50 | name of fuel (e.g. MMH, LH2) | |
| ignore_noz_sep = | 0 | flag to force nozzle flow separation to be ignored (USE WITH CAUTION) | |
| MRcore = | 1.87985 | mixture ratio of core flow (ox flow rate / fuel flow rate) | |
| oxName = | N2O4 | name of oxidizer (e.g. N2O4, LOX) | |
| Pamb = | 0.00 psia |
0.00 MPa 0.00 atm 0.00 bar |
ambient pressure (for example sea level is 14.7 psia) |
| Pc = | 100.0 psia |
0.69 MPa 6.80 atm 6.89 bar |
chamber pressure |
| Output | |||
|---|---|---|---|
| Parameter = | Value | Alt Value | Description |
| CfAmbDel = | 1.83044 | delivered ambient thrust coefficient | |
| CfVacDel = | 1.83044 | delivered vacuum thrust coefficient | |
| CfVacIdeal = | 1.95937 | ideal vacuum thrust coefficient | |
| cstarERE = | 5534.6 ft/s | 1686.9 m/s | delivered core cstar |
| cstarODE = | 5647.5 ft/s | 1721.4 m/s | core ideal cstar |
| FvacBarrier = | 2691.2 lbf | 11971.1 N | vacuum thrust due to barrier stream tube |
| FvacCore = | 17808.8 lbf | 79217.4 N | vacuum thrust due to core stream tube |
| FvacTotal = | 20500.0 lbf | 91188.5 N | total vacuum thrust |
| gammaChm = | 1.13146 | core gas ratio of specific heats (Cp/Cv) | |
| IspDel = | 313.18 sec |
3071.29 N-sec/kg 3.07 km/sec |
<=== thruster delivered vacuum Isp ===> |
| IspDel_core = | 320.87 sec |
3146.66 N-sec/kg 3.15 km/sec |
delivered Isp of core stream tube |
| IspODE = | 343.93 sec |
3372.79 N-sec/kg 3.37 km/sec |
core one dimensional equilibrium Isp |
| IspODF = | 316.89 sec |
3107.63 N-sec/kg 3.11 km/sec |
core frozen Isp |
| IspODK = | 333.56 sec |
3271.15 N-sec/kg 3.27 km/sec |
core one dimensional kinetic Isp |
| MRthruster = | 1.59787 | total thruster mixture ratio') | |
| MWchm = | 21.691 g/gmole | core gas molecular weight | |
| Pexit = | 0.1179 psia |
0.00 MPa 0.01 atm 0.01 bar |
nozzle exit pressure |
| TcODE = | 5606.3 degR |
3114.6 degK 2841.4 degC 5146.6 degF |
ideal core gas temperature |
| wdotFl = | 25.196 lbm/s | 11.429 kg/s | total fuel flow rate |
| wdotOx = | 40.260 lbm/s | 18.262 kg/s | total oxidizer flow rate |
| wdotTot = | 65.457 lbm/s | 29.691 kg/s | total propellant flow rate (ox+fuel) |
| At Injector Face | |||
| Parameter = | Value | Alt Value | Description |
| wdotFl_cInit = | 21.417 lbm/s | 9.715 kg/s | initial core fuel flow rate (before any entrainment) |
| wdotFlFFC = | 3.779 lbm/s | 1.714 kg/s | fuel film coolant flow rate injected at perimeter |
| wdotTot_cInit = | 61.677 lbm/s | 27.976 kg/s | initial core total flow rate (before any entrainment) |
| After Entrainment | |||
| Parameter = | Value | Alt Value | Description |
| wdotFl_b = | 5.924 lbm/s | 2.687 kg/s | barrier fuel flow rate (FFC + entrained) |
| wdotFl_c = | 19.272 lbm/s | 8.742 kg/s | final core fuel flow rate (injected - entrained) |
| wdotOx_b = | 4.031 lbm/s | 1.829 kg/s | barrier oxidizer flow rate (all entrained) |
| wdotOx_c = | 36.229 lbm/s | 16.433 kg/s | final core oxidizer flow rate (injected - entrained) |
| wdotTot_b = | 9.955 lbm/s | 4.516 kg/s | total barrier propellant flow rate (includes entrained) |
| wdotTot_c = | 55.502 lbm/s | 25.175 kg/s | total final core propellant flow rate (injected - entrained) |
| Efficiencies |
|---|
| Output | ||
|---|---|---|
| Parameter = | Value | Description |
| Isp = | 0.91061 | Overall Isp Efficiency |
| Noz = | 0.95199 | Nozzle Efficiency |
| ERE = | 0.98000 | (constant) Energy Release Efficiency of Chamber |
| FFC = | 0.97605 | (barrier calc) Fuel Film Cooling Efficiency of Chamber |
| Nozzle | ||
| Parameter = | Value | Description |
| Div = | 0.98851 | (simple fit eps=62.5, %bell=72.3) Divergence Efficiency of Nozzle |
| Kin = | 0.96986 | (MLP fit) Kinetic Efficiency of Nozzle |
| BL = | 0.99298 | (MLP fit) Boundary Layer Efficiency of Nozzle |
| Ignored Efficiencies |
|---|
| TP: Two Phase Efficiency of Nozzle |
| Barrier Stream Tube |
|---|
| Input | ||
|---|---|---|
| Parameter = | Value | Description |
| ko = | 0.035 | entrainment constant (typical value is 0.035, range from 0.03 to 0.06) |
| pcentFFC = | 15 | percent fuel film cooling ( FFC flowrate / total fuel flowrate) |
| Output | |||
|---|---|---|---|
| Parameter = | Value | Alt Value | Description |
| cstarERE_b = | 4988.4 ft/s | 1520.5 m/s | delivered cstar |
| cstarODE_b = | 5090.2 ft/s | 1551.5 m/s | ideal equilibrium cstar |
| fracKin_b = | 0 | fraction of kinetic completion in barrier | |
| IspDel_b = | 270.33 sec |
2651.07 N-sec/kg 2.65 km/sec |
delivered vacuum barrier Isp |
| IspODE_b = | 294.85 | sec. ideal equilibrium barrier Isp | |
| IspODF_b = | 281.03 sec |
2755.95 N-sec/kg 2.76 km/sec |
ideal frozen barrier Isp |
| IspODK_b = | 281.03 sec |
2755.95 N-sec/kg 2.76 km/sec |
vacuum kinetic Isp of barrier |
| MRbarrier = | 0.680508 | barrier mixture ratio | |
| MRwall = | 0.253152 | mixture ratio at wall | |
| TcODE_b = | 3453.4 degR |
1918.6 degK 1645.4 degC 2993.7 degF |
average ideal ODE temperature of barrier gas |
| Twallgas = | 2149.3 degR |
1194.1 degK 920.9 degC 1689.6 degF |
temperature of gas at wall |
| WentrOvWcool = | 1.63403 | ratio of entrained flow rate to FFC flow rate | |