BACKGROUND: The core engine of this program was written by Tom Benson of NASA Glenn as a Java applet and made available to the general public through the following URL:
http://www.grc.nasa.gov/WWW/K-12/rocket/ienzl.html
Because Java is no longer widely distributed for browsers (it's considered a security risk); the code and page was "lost". In January-May 2014, I ported the code over to C++. Now, six years later, during the Coronavirus pandemic (and also because I started playing Kerbal Space Program again), I decided to port it again, from C++ to in-browser JavaScript. Development of the JavaScript web-version began on 6 July 2020 and it was good enough for release by 19 July 2020. This version doesn't feature all of the options for changing variables that the original NASA Glenn program does, being more oriented towards calculating rocket engine performance than playing with variables. I found that the code(s) written by Mr. Benson were reasonably accurate if you provided the code with reasonably accurate:
Combustion TemperaturesMolecular WeightsGamma (ratio of specific heats)
for the propellant combination being used. The values for these were obtained through Rocket Propulsion Analysis, which is programmed by Alexander Ponomarenko.
NOTE: The code for the program is contained entirely within this HTML file; so you can download it for offline use on your own PC, or to extend/edit it yourself, without having to worry about tracking down dependencies from elsewhere.
MANUAL DATA INPUT
Yellow boxes are secondary input fields; enter your data and hit enter, and they will automatically translate/convert into the primary input fields.
Example Expansion Ratios are: NAA-75-110-A (Redstone): 3.61 H-1 (Saturn I): 8 F-1 (Saturn V): 16 J-2 (Saturn V): 27.5 RD-180 (Atlas V): 36.87 RL10A-1 (Centaur): 40 RL10A-3 (Centaur): 57 RS-25 SSME (Shuttle): 69 RL10B-2 (Centaur): 280 RL100 Adv. Expander Cycle Engine (Study): 640
Chamber Pressure and Engine Cycles
Chamber pressures and engine cycles are closely linked. Some examples are:
Full Flow Staged Combustion: 4,400~ PSI (Raptor) Oxygen Rich Staged Combustion: 3,800~ PSI (RD-180) Fuel Rich Staged Combustion: 2,000 to 3,000~ PSI (RS-25 SSME) Gas Generator: 227 to 1,400 PSI (V-2 to Merlin 1D) Expander: 500 to 885 PSI, LH2 Only (RL10 to Vinci) Pressure-Fed: 0 to 100 PSI (Limited due to mass fraction of fuel tanks)
Engine Operating Efficiency (EOE) Examples
EOE is a combination of thrust chamber efficiency and nozzle efficiency. Some examples are:
Maximum Theoretical Impulse: 1 Oxygen Rich Staged Combustion: 0.980 to 0.990 (RD-180) Staged Combustion: 0.970 to 0.975 (RS-25 SSME) Gas Gen. (Regen Nozzle): 0.948 to 0.95 (H-1/J-2/RL10A) NERVA I: 0.9465 LANL Small Nuclear Engine: 0.931 (Mini-NERVA designed for STS) Gas Gen. (Partial Regen): 0.92 (F-1) Pressure Fed, Large: 0.9026 (RS-18 LMAE) Gas Gen. (Steering Vane): 0.881 (V-2 Engine) Pressure Fed, Small: 0.795 to 0.850 (RCS thrusters)