Propulsion

1 tool in the Aerodynamics area.

Propeller and Jet Thrust

Thrust and efficiency of the three classical propulsion models, chosen by a select: the Rankine-Froude momentum theory of the propeller disc (induced velocity, ideal power, the ideal efficiency 2/(1 + sqrt(1 + T/(q A))), disc and power loading, static thrust and figure of merit), the blade-element momentum theory of a propeller (Glauert's formulation with the Prandtl tip and hub loss factor, solved station by station for the induced velocities, with the NACA 5868-9 blade of Report 640 or a typed chord, blade-angle and thickness table and a stated Clark Y section polar: thrust, torque, power, C_T, C_P, C_Q and efficiency against the advance ratio, the radial distributions and, for the 5868-9 blade, the measured curves of Report 640 overlaid), and the gas-turbine cycle of a turbojet, separate-exhaust turbofan or ramjet with inlet, compressor, burner, turbine and nozzle efficiencies (station states, fuel-air ratio, specific thrust, thrust specific fuel consumption, thermal, propulsive and overall efficiencies, a convergent nozzle that chokes or a convergent-divergent one, constant cp or the variable specific heat of air from the NASA Glenn polynomials, the parametric chart against the compressor pressure ratio). The default is Report 640's three-blade 10 ft propeller 5868-9 at 1,000 rpm and 100 mph at sea level, set 20 degrees at 0.75R, for which the page gives a thrust of 249 lb at 77.9 hp and an efficiency of 0.852 at J = 0.88, checked against an independent numerical solution and the report's measured curves; the jet default is a turbojet at Mach 0.8 with a compressor pressure ratio of 20 and a turbine inlet temperature of 1,500 K (2,700 °R), at the shared altitude input (sea level as loaded; 35,000 ft for a cruise case), checked against the closed forms of the ideal cycle and the same independent solution.

1 worked example reproduced, listed on the tool page.

Other Aerodynamics sections

Airfoils and Wings · Rotors and Propellers · Aircraft Performance · Stability and Control · Atmosphere and Flight Conditions