Test and analysis on high and low temperature on starting performance of a turboshaft engine

The comparative analysis test of the starting performance of turboshaft engine with RP-3 and RP-5 fuel was carried out.The variation law of resistance torque and electric motor torque under different ambient temperature was analyzed and the limitation of current calculation method was pointed out.The influences of ambient temperature，fuel type and fuel flow rate on the starting limit temperature of the engine were found out.The test results showed that with the decrease of temperature，the viscosity of oil increased，the rotor resistance torque increased and the engine belt speed and rotor rotation time decreased significantly.Under the extreme low temperature conditions，the two kinds of fuel had great influence on the starting performance of turboshaft engine.However，under the high temperature condition，the engine starting performance with the above fuels was the same.The engine can start successfully at $-\mathrm{40}$ ℃ with RP-3 fuel，but it can only start successfully at -20 ℃ with RP-5 fuel after adjusting the fuel.Increasing the fuel flow within a certain range can improve the starting ability of the engine using RP-5 fuel.The research results provide a reference for high and low temperature tests of similar engines.