Experimental Clarification on Detonation Phenomena of Liquid Ethanol Rotating Detonation Combustor

Rotating detonation combustion was successfully tested for liquid ethanol and gaseous oxygen heterogeneous mixture in a cylindrical combustor for the first time. The rotating detonation combustor (RDC) we operated has a diameter of 20 mm and variable lengths of 60, 210 mm. Pure ethanol and industrial ethanol were selected as liquid fuels. Under the conditions of ethanol and oxygen mass flow rate of 26-40 g/s, equivalence ratio of 0.4-1.7, and backpressure of 10-17 kPa, we confirmed detonation combustion and deflagration combustion. In detonation combustion, as the ethanol manifold supply temperature increases, the detonation propagation speeds, and luminance of combustion were enhanced. It is possible to say enhanced evaporation behavior resulted in stable detonation and showed high peaks in luminance value. Utilizing the control surface method to evaluate experimental thrust, estimated thrust showed good agreement with experimental thrust. For liquid-fueled cylindrical RDCs, the control surface methods can also be used to evaluate thrust.