QuickStart¶
Install RocketIsp¶
The easiest way to install Rocketisp is:
pip install rocketisp
OR on Linux
sudo pip install rocketisp
OR perhaps
pip install --user rocketisp
Installation From Source¶
Much less common, but if installing from source, then
the best way to install rocketisp is still pip.
After navigating to the directory holding Rocketisp source code, do the following:
cd full/path/to/rocketisp
pip install -e .
OR on Linux
sudo pip install -e .
OR perhaps
pip install --user -e .
This will execute the local setup.py file and insure that the pip-specific commands in setup.py are run.
Running RocketIsp¶
To test the installation, from the command prompt input the command:
python -c "from rocketisp.rocket_isp import RocketThruster; RocketThruster().summ_print()"
If Rocketisp is properly installed, then output similar to the following should result.
============================== RocketIsp Thruster ==============================
................................. Geometry .................................
.................................. Input ..................................
cham_conv_deg = 30.00 deg half angle of conical convergent section
CR = 2.5 chamber contraction ratio (Ainj / Athroat)
eps = 20 nozzle area ratio (Aexit / Athroat)
LchamberInp = None in user input value of chamber length (will override all other entries)
LchmMin = 1.000 in minimum chamber length (will override LchmOvrDt)
(2.540 cm, 0.083 ft)
LchmOvrDt = 3 ratio of chamber length to throat diameter (Lcham / Dthrt)
LnozInp = None in user input nozzle length (will override pcentBell)
pcentBell = 80 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 = 1.000 in throat radius
(2.540 cm, 0.083 ft)
RupThroat = 1.5 radius of curvature just upstream of throat (Rupstream / Rthrt)
............................................................................
............................... Output ....................................
Ainj = 7.854 in**2 area of injector
(50.671 cm**2)
At = 3.142 in**2 throat area
(20.268 cm**2)
Dexit = 8.944 in nozzle exit diameter
(22.718 cm, 0.745 ft)
Dinj = 3.162 in diameter of injector
(8.032 cm, 0.264 ft)
Dthrt = 2.000 in throat diameter
(5.080 cm, 0.167 ft)
entrance_angle = 31.52 deg nozzle initial expansion angle
exit_angle = 8.84 deg nozzle exit angle
Lcham_conv = 1.676 in length of convergent section of chamber
(4.258 cm, 0.140 ft)
Lcham_cyl = 4.324 in length of cylindrical section of chamber
(10.982 cm, 0.360 ft)
Lnoz = 10.367 in nozzle length
(26.331 cm, 0.864 ft)
Ltotal = 16.367 in nozzle + chamber length
(41.571 cm, 1.364 ft)
Rinj = 1.581 in radius of injector
(4.016 cm, 0.132 ft)
Vcham = 42.9 in**3 approximate chamber volume
(702.6 cm**3)
............................................................................
........................ N2O4/MMH Core Stream Tube .........................
.................................. Input ..................................
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 = 0.990012 Cd of throat (RocketThruster object may override)
((MLP fit))
fuelName = MMH name of fuel (e.g. MMH, LH2)
ignore_noz_sep = 0 flag to force nozzle flow separation to be ignored (USE WITH CAUTION)
MRcore = 1.9 mixture ratio of core flow (ox flow rate / fuel flow rate)
oxName = N2O4 name of oxidizer (e.g. N2O4, LOX)
Pamb = 0.00 psia ambient pressure (for example sea level is 14.7 psia)
(0.00 MPa, 0.00 atm, 0.00 bar)
Pc = 500.0 psia chamber pressure
(3.45 MPa, 34.02 atm, 34.47 bar)
............................................................................
............................... Output ....................................
CfAmbDel = 1.76084 delivered ambient thrust coefficient
CfVacDel = 1.76084 delivered vacuum thrust coefficient
CfVacIdeal = 1.82576 ideal vacuum thrust coefficient
cstarERE = 5743.3 ft/s delivered core cstar
(1750.5 m/s)
cstarODE = 5743.3 ft/s core ideal cstar
(1750.5 m/s)
FvacCore = 2765.9 lbf vacuum thrust due to core stream tube
(12303.4 N)
FvacTotal = 2765.9 lbf total vacuum thrust
(12303.4 N)
gammaChm = 1.14849 core gas ratio of specific heats (Cp/Cv)
IspDel = 317.49 sec <=== thruster delivered vacuum Isp ===>
(3113.53 N-sec/kg, 3.11 km/sec)
IspDel_core = 317.49 sec delivered Isp of core stream tube
(3113.53 N-sec/kg, 3.11 km/sec)
IspODE = 325.91 sec core one dimensional equilibrium Isp
(3196.07 N-sec/kg, 3.20 km/sec)
IspODF = 311.72 sec core frozen Isp
(3056.94 N-sec/kg, 3.06 km/sec)
IspODK = 322.47 sec core one dimensional kinetic Isp
(3162.36 N-sec/kg, 3.16 km/sec)
MRthruster = 1.9 total thruster mixture ratio')
MWchm = 21.725 g/gmole core gas molecular weight
Pexit = 2.4378 psia nozzle exit pressure
(0.02 MPa, 0.17 atm, 0.17 bar)
TcODE = 5879.0 degR ideal core gas temperature
(3266.1 degK, 2993.0 degC, 5419.4 degF)
wdotFl = 3.004 lbm/s total fuel flow rate
(1.363 kg/s)
wdotOx = 5.708 lbm/s total oxidizer flow rate
(2.589 kg/s)
wdotTot = 8.712 lbm/s total propellant flow rate (ox+fuel)
(3.952 kg/s)
............................................................................
Efficiencies
Output
Isp = 0.97417 Overall Isp Efficiency
Noz = 0.97417 Nozzle Efficiency
ERE = 1.00000 Energy Release Efficiency of Chamber
..Nozzle..
Div = 0.99100 (simple fit eps=20, %bell=80) Divergence Efficiency of Nozzle
Kin = 0.98945 (MLP fit) Kinetic Efficiency of Nozzle
BL = 0.99350 (MLP fit) Boundary Layer Efficiency of Nozzle
Ignored Efficiencies
TP: Two Phase Efficiency of Nozzle
Mix: Inter-Element Mixing Efficiency of Injector
Em: Intra-Element Mixing Efficiency of Injector
Vap: Vaporization Efficiency of Injector
HL: Heat Loss Efficiency of Chamber
RocketIsp GUI¶
After installing with pip, there will be a launch command line program called
rocketisp or, on Windows, rocketisp.exe placed into your python Scripts subdirectory.
From a terminal or command prompt window simply type:
rocketisp
and the following tkinter GUI should appear.
If not, then there may be an issue with your system path. The path for the rocketisp executable might be something like:
/usr/local/bin/rocketisp (if installed with sudo pip install -e .)
or
/home/<user>/.local/bin/rocketisp (if installed with pip install -e .)
or
C:\Python37_64\Scripts\rocketisp.exe (on Windows)
Make sure your system path includes the above path to rocketisp.
