I designed a 100 lbf (445 N) LOX/ethanol engine, similar to Robert Watzlavick’s heat sink kerolox engine.
The analysis is nothing more than the 1D isentropic compressible flow equations and thermodynamic data from RPA: 100 lbf engine
Propellants: 70%ethanol and liquid oxygen
Thrust: 445 N (100 lbf)
Mixture Ratio (O/F): 1.1
Specific Impulse: 221 s
Chamber Pressure: 1.379 MPa (200 psi)
Exit Diameter: 3.03 cm (1.192 inches)
Throat Diameter: 1.76 cm (0.691 inches)
L*: 119 cm (46.9 inches)
Oxidizer Orifice Diameter: 0.762 mm (0.030 inches)
Fuel Orifice Diameter: 0.787 mm (0.031 inches)
I used the free version of Rocket Propulsion Analysis to get the thermodynamic properties of the LOX/ethanol combustion products (temperature, specific heat ratio, and density) as functions of mixture ratio, chamber pressure, and alcohol concentration. RPA has a very intuitive user interface and the free version is surprisingly versatile and powerful. Version 2 includes film and regenerative cooling analysis. The student version is $200, but there’s a 15 day free trial.