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Monomethylhydrazine

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The big problem is the NASA equations. It uses the variables Ttotal and Ptotal. NASA states, "pt is the total pressure in the combustion chamber, Tt is the total temperature in the combustion chamber." However, when I plug in 300 psi and 5742 degrees fahrenheit and the exhaust values for each variable as given by NASA's isentropic equations, I get a thrust of 735 pounds, whereas the first time I ran the numbers I got 32 pounds of thrust.

Here is my data, most of it was from a formula. The top ten rows are all givens. I got that information from https://risacher.org/rocket/eqns.html as I am building a gasoline-GOX engine.

What it is Value Unit

Combustion pressure (Pc) 300 PSI

Mixture Ratio 2.5 n/a

Flame Temp 5742 Fahrenheit

ISP 261 Seconds

GOX Density 0.083 lb/ft^3

Gas Density 44.5 lb/ft^3

Nozzle Throat Cross Sectional Area 0.00173611 ft^2

Gas constant (R) 65 ftlb/lb

Gamma (heat ratio) 1.2

gc (gravitation) 32 ft/second/second

Tt (temperature of gasses at nozzle throat) 5637.618 Fahrenheit

Tc (temperature of cumbustion flame) 6202 Rankine

Pt (gas pressure at nozzle throat) 169.2 PSI

Me (mach number of gasses at exit) 2.55

Area Exhaust/Area throat 3.65

Temperature Exhuast/Temperature combustion 0.606

Thrust 31.84104294 Pounds

Mass flow rate 0.0009229501076 pounds per second

Exhaust velocity 1380.669321 ft/second

Temperature Exhuast 3479.652 Fahrenheit

Exhaust pressure 24.4297 psiAs you might imagine, I would really appreciate someone going over and double checking my numbers. Thank you so much!