"""
model the XLR-134
"""
from rocketisp.rocket_isp import RocketThruster
from rocketisp.geometry import Geometry
from rocketisp.stream_tubes import CoreStream
from rocketisp.efficiencies import Efficiencies
geomObj = Geometry(Rthrt=1,
CR=3.0, eps=767.9, pcentBell=80,
RupThroat=1.5, RdwnThroat=1.0, RchmConv=1.0, cham_conv_deg=30,
LchmOvrDt=3.10, LchmMin=2.0, LchamberInp=None)
effObj = Efficiencies()
effObj.set_const('ERE', (490.45-8.6)/490.45)
core = CoreStream( geomObj, effObj, oxName='LOX', fuelName='LH2', MRcore=6.0,
Pc=510 )
R = RocketThruster(name='xlr134',coreObj=core, injObj=None)
R.scale_Rt_to_Thrust( 500 , Pamb=0.0 , use_scipy=False )
R.summ_print()
from rocketisp.geometry import Geometry
from rocketisp.efficiencies import Efficiencies
geomObj = Geometry(Rthrt=5.868 / 2,
CR=2.5,
eps=150,
pcentBell=80,
RupThroat=1.5,
RdwnThroat=1.0,
RchmConv=1.0,
cham_conv_deg=30,
LchmOvrDt=3.10,
LchmMin=2.0,
LchamberInp=16)
effObj = Efficiencies()
effObj.set_const('Mix', 0.997329)
effObj.set_const('Em', 0.99644)
effObj.set_const('Kin', 0.975011)
effObj.set_const('BL', 0.9795)
effObj.set_const('Div', 0.994775)
core = CoreStream(geomObj,
effObj,
oxName='N2O4',
fuelName='MMH',
MRcore=1.85,
Pc=150,
CdThroat=0.995,
Pamb=14.7,
pcentFFC=14.0,
dpOxInp = 200
dpFuelInp = 200
geomObj = Geometry(Rthrt=Rt,
CR=CR,
eps=eps,
pcentBell=pcentBell,
RupThroat=0.5,
RdwnThroat=1.0,
RchmConv=0.5,
cham_conv_deg=30,
LchmOvrDt=3,
LchmMin=2.0,
LchamberInp=Lcham)
effObj = Efficiencies()
effObj.set_const('ERE', 0.975)
effObj.set_const('Noz', 0.933177) # Huzel based on frozen Isp
core = CoreStream(geomObj,
effObj,
oxName=oxName,
fuelName=fuelName,
MRcore=MR,
Pc=Pc,
Pamb=14.7,
CdThroat=1.0,
adjCstarODE=0.978196,
adjIspIdeal=1.0084418978404621)
C = RocketThruster(name='Huzel A-1', coreObj=core, calc_CdThroat=False)
from rocketisp.geometry import Geometry
from rocketisp.efficiencies import Efficiencies
from rocketisp.stream_tubes import CoreStream
from rocketisp.rocket_isp import RocketThruster
# create CoreStream with area ratio=375:1, Pc=137, FFC=30% and effERE=0.99
C = CoreStream( geomObj=Geometry(eps=375),
effObj=Efficiencies(ERE=0.99), pcentFFC=30,
oxName='N2O4', fuelName='N2H4', MRcore=1.26 ,
Pc=137, Pamb=0)
# instantiate RocketThruster
R = RocketThruster(name='100 lbf Aerojet HiPAT R-4D', coreObj=C)
R.scale_Rt_to_Thrust( 100 , Pamb=0.0 )
R.summ_print()
#C.effObj.summ_print()
dpOxInp = 25
dpFuelInp = 25
geomObj = Geometry(Rthrt=Rt,
CR=CR,
eps=eps,
pcentBell=pcentBell,
RupThroat=0.5,
RdwnThroat=1.0,
RchmConv=0.5,
cham_conv_deg=30,
LchmOvrDt=3,
LchmMin=2.0,
LchamberInp=Lcham)
effObj = Efficiencies()
effObj.set_const('ERE', 0.98)
effObj.set_const('Noz', 0.946901)
core = CoreStream(geomObj,
effObj,
oxName=oxName,
fuelName=fuelName,
MRcore=MR,
Pc=Pc,
Pamb=14.7,
CdThroat=1.0,
adjCstarODE=0.975554,
adjIspIdeal=1.01214)
C = RocketThruster(name='Huzel A-4', coreObj=core, calc_CdThroat=False)
"""
Apollo SPS, Aerojet AJ10-137 (Apollo Service Module Engine)
"""
from rocketisp.rocket_isp import RocketThruster
from rocketisp.geometry import Geometry
from rocketisp.stream_tubes import CoreStream
from rocketisp.efficiencies import Efficiencies
# create basic Geometry.
# Use "place-holder" of 1 inch for throat radius... correct later with "scale_Rt_to_Thrust"
geomObj = Geometry(Rthrt=1,
CR=2.5, eps=62.5, pcentBell=72.3,
RupThroat=1.5, RdwnThroat=1.0, RchmConv=1.0, cham_conv_deg=30,
LchmOvrDt=3.10, LchmMin=2.0, LchamberInp=None)
effObj = Efficiencies()
effObj.set_const('ERE', 0.98) # don't know injector details so set effERE=0.98
# It's an ablative chamber, so some FFC (fuel film cooling) is required... guess about 15%
core = CoreStream( geomObj=geomObj, effObj=effObj, pcentFFC=15.0,
oxName='N2O4', fuelName='A50', MRcore=1.6, Pc=100 )
R = RocketThruster(name='Apollo SPS',coreObj=core)
# scale geometry to give 20,500 lbf of thrust for current conditions
R.scale_Rt_to_Thrust( 20500 , Pamb=0.0 )
# figure out best mixture ratio to run the engine.
R.set_mr_to_max_ispdel()
# re-scale geometry to give 20,500 lbf of thrust after MR change
def test_overall_Isp_efficiency(self):
"""test overall Isp efficiency"""
E = Efficiencies(Isp=0.95)
self.assertAlmostEqual(E('Isp'), .95, places=5)
def calc_PI_adiabatic_isp(oxName='N2O4', fuelName='MMH',
eps=10.0, pcentBell=80.0, Pc=100., Fvac=1000.0,
NumRuns=20, do_show=True):
# ============ use RocketCEA to find MR range ===================
mc = MR_Temperature_Limits( oxName=oxName, fuelName=fuelName,
PcNominal=Pc, epsNominal=eps)
mr_peak = MR_Peak_At_EpsPc(mc, pc=Pc, eps=eps, ispType='CEAODE', # ispType can be CEAODE, CEAFROZEN
NterpSize=100)
print('Peak IspODE=%g sec at MR ='%mr_peak.ispPeak, mr_peak.mrPeak)
print()
print('MR at 97% Isp (on low side) =', mr_peak.calc_mrLow_minus_NPcentIsp())
print('MR at 97% Isp (on high side) =', mr_peak.calc_mrHigh_minus_NPcentIsp())
mr_lo = round( mr_peak.mrLeftOfPeak - (mr_peak.mrRightOfPeak - mr_peak.mrLeftOfPeak)/10.0, 2)
mr_hi = round( mr_peak.mrRightOfPeak, 2)
delMR = (mr_hi - mr_lo) / (NumRuns - 1)
geomObj = Geometry(Rthrt=5.868/2,
CR=2.5, eps=eps, pcentBell=pcentBell,
RupThroat=1.5, RdwnThroat=1.0, RchmConv=1.0, cham_conv_deg=30,
LchmOvrDt=3.10, LchmMin=2.0, LchamberInp=16)
effObj = Efficiencies()
core = CoreStream( geomObj, effObj, oxName=oxName, fuelName=fuelName, MRcore=1.6,
Pc=Pc)
R = RocketThruster(name='sample',coreObj=core, injObj=None, calc_CdThroat=False, noz_regen_eps=eps)
ispodeL = []
ispodkL = []
isptdkL = []
ispPIL = []
mrL = []
MR = mr_lo
for _ in range(NumRuns):
mrL.append( MR )
core.reset_attr( 'MRcore', MR, re_evaluate=True)
R.scale_Rt_to_Thrust( Fvac, Pamb=0.0, use_scipy=False )
ispodeL.append( R.coreObj.IspODE )
ispodkL.append( R.coreObj.IspODK )
isptdkL.append( R.coreObj.IspODK * R.coreObj.effObj('Div') )
ispPIL.append( R.coreObj.IspODK * R.coreObj.effObj('Div') * R.coreObj.effObj('BL') )
MR += delMR
fig, ax = plt.subplots( figsize=(8,6) )
plt.plot(mrL, ispodeL, label='IspODE', color=COLORL[0])
plt.plot(mrL, ispodkL, label='IspODK', color=COLORL[1])
plt.plot(mrL, isptdkL, label='IspTDK', color=COLORL[2])
plt.plot(mrL, ispPIL, label='IspPI', color=COLORL[3])
# ======= find peaks ======
mr_ode_terp = InterpProp(mrL, ispodeL)
mr_ode_Peak, isp_ode_peak = gold_search_max(mr_ode_terp, mrL[0], mrL[-1], tol=1.0e-5)
mr_odk_terp = InterpProp(mrL, ispodkL)
mr_odk_Peak, isp_odk_peak = gold_search_max(mr_odk_terp, mrL[0], mrL[-1], tol=1.0e-5)
mr_tdk_terp = InterpProp(mrL, isptdkL)
mr_tdk_Peak, isp_tdk_peak = gold_search_max(mr_tdk_terp, mrL[0], mrL[-1], tol=1.0e-5)
mr_pi_terp = InterpProp(mrL, ispPIL)
mr_pi_Peak, isp_pi_peak = gold_search_max(mr_pi_terp, mrL[0], mrL[-1], tol=1.0e-5)
# show ========= optimum MR difference ========
def span_mrpeak( isL ):
minpt = min(isL)
maxpt = max(isL)
span = maxpt - minpt
return [maxpt-0.8*span, maxpt]
plt.plot([mr_ode_Peak, mr_ode_Peak], span_mrpeak(ispodeL), '--', label='MRode=%.2f'%mr_ode_Peak, linewidth=2, color=COLORL[0])
plt.plot([mr_odk_Peak, mr_odk_Peak], span_mrpeak(ispodkL), '--', label='MRodk=%.2f'%mr_odk_Peak, linewidth=2, color=COLORL[1])
plt.plot([mr_tdk_Peak, mr_tdk_Peak], span_mrpeak(isptdkL), '--', label='MRtdk=%.2f'%mr_tdk_Peak, linewidth=2, color=COLORL[2])
plt.plot([mr_pi_Peak, mr_pi_Peak], span_mrpeak(ispPIL), '--', label='MRpi=%.2f'%mr_pi_Peak, linewidth=2, color=COLORL[3])
isp_pi_peak = abs(isp_pi_peak)
plt.text( mr_pi_Peak, isp_pi_peak, '%i'%int(isp_pi_peak), ha='left', va='bottom', transform=ax.transData, color=COLORL[3] )
plt.legend()
plt.title('Perfect Injector')
plt.title( "%s/%s RocketIsp\nPerfect Injector w Adiabatic Wall\nFvac=%.0f lbf, Pc=%.0f psia, AR=%.0f:1, %%Bell=%.0f%%"%\
(oxName, fuelName, Fvac, Pc, eps, pcentBell))
plt.ylabel('Isp (sec)')
plt.xlabel('Mixture Ratio')
png_name = '%s_%s_Fvac%g_Pc%g_eps%g.png'%(oxName, fuelName, int(Fvac), Pc, eps)
plt.savefig(png_name, dpi=120)
if do_show:
plt.show()
from rocketisp.efficiencies import Efficiencies
from rocketisp.examples.compare_vals import compare_header, compare
geomObj = Geometry(Rthrt=3,
CR=2.5,
eps=55,
pcentBell=80,
RupThroat=1.5,
RdwnThroat=1.0,
RchmConv=1.0,
cham_conv_deg=30,
LchmOvrDt=3.10,
LchmMin=2.0,
LchamberInp=None)
effObj = Efficiencies()
effObj.set_const('ERE', 0.97)
core = CoreStream(geomObj=geomObj,
effObj=effObj,
oxName='N2O4',
fuelName='MMH',
MRcore=1.65,
Pc=125)
R = RocketThruster(name='Shuttle OMS', coreObj=core, injObj=None)
R.scale_Rt_to_Thrust(6000, Pamb=0.0)
compare_header()
compare('Fvacuum', 6000, core('FvacTotal'))
compare('Isp Vacuum', 313.2, core('IspDel'))
from rocketisp.rocket_isp import RocketThruster
from rocketisp.injector import Injector
geomObj = Geometry(Rthrt=1,
CR=2.5,
eps=20.0,
pcentBell=80,
RupThroat=1.5,
RdwnThroat=1.0,
RchmConv=1.0,
cham_conv_deg=30,
LchmOvrDt=3.10,
LchmMin=2.0,
LchamberInp=None)
effObj = Efficiencies()
# It's an ablative chamber, so some FFC (fuel film cooling) is required... guess about 10%
C = CoreStream(geomObj=geomObj,
effObj=effObj,
pcentFFC=0.0,
Pamb=0.0,
oxName='N2O4',
fuelName='MMH',
MRcore=1.9,
Pc=500)
I = Injector(
C,
Tox=None,
Tfuel=None,
from rocketisp.geometry import Geometry
from rocketisp.efficiencies import Efficiencies
from rocketisp.stream_tubes import CoreStream
C = CoreStream(geomObj=Geometry(eps=35),
effObj=Efficiencies(ERE=0.98, Noz=0.97),
oxName='LOX',
fuelName='CH4',
MRcore=3.6,
Pc=500,
Pamb=14.7)
for name in ['IspODE', 'IspDel', 'IspODF']:
print('%8s =' % name, '%.1f' % C(name))
print('%8s =' % 'IspAmb', '%.1f' % C('IspAmb'), C('noz_mode'))
C.summ_print()
from plothelp.plot_help import Figure, sample_data, Curve, plt
from plothelp.plot_help import CWheel
geomObj = Geometry(Rthrt=1,
CR=2.5,
eps=20.0,
pcentBell=80,
RupThroat=1.5,
RdwnThroat=1.0,
RchmConv=1.0,
cham_conv_deg=30,
LchmOvrDt=3.10,
LchmMin=2.0,
LchamberInp=None)
effObj = Efficiencies(Vap=0.99, Mix=0.99)
# It's an ablative chamber, so some FFC (fuel film cooling) is required... guess about 10%
C = CoreStream(geomObj=geomObj,
effObj=effObj,
pcentFFC=0.0,
Pamb=0.0,
oxName='N2O4',
fuelName='MMH',
MRcore=1.9,
Pc=500)
mrr = MRrange(C.ceaObj, Pc=C.Pc, eps=geomObj.eps, edge_frac=0.97)
mrlo, mrhi = mrr.get_mr_range()
print('mrlo, mrhi', mrlo, mrhi)
mrcoreL = np.linspace(mrlo, mrhi,
from rocketisp.geometry import Geometry
from rocketisp.efficiencies import Efficiencies
from rocketisp.stream_tubes import CoreStream
from rocketisp.rocket_isp import RocketThruster
# create CoreStream with area ratio=375:1, Pc=137, FFC=30% and effERE=0.99
C = CoreStream(geomObj=Geometry(eps=375),
effObj=Efficiencies(ERE=0.99),
pcentFFC=30,
oxName='N2O4',
fuelName='N2H4',
MRcore=1.26,
Pc=137,
Pamb=0)
# instantiate RocketThruster
R = RocketThruster(name='100 lbf Aerojet HiPAT R-4D', coreObj=C)
R.scale_Rt_to_Thrust(100, Pamb=0.0)
R.summ_print()
#C.effObj.summ_print()
