Apollo SPS

RocketIsp version 0.1.8 Friday, Dec 04, 2020 at 04:33PM
      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
Plot
Plot
Plot
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)
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