AN EXPERIMENTAL INVESTIGATION OF HYDROGEN-AIR SUPERSONIC COMBUSTION

The experimental results of Hydrogen fueled supersonic combustors are considered.Tests were conducted with arc heated air at inlet Mach number 2 1,total temperature 2100K,total pressure 7×10 5Pa.The axisymmetric combustor with inlet of 4 6cm inner diameter has been investigated with hydrogen injected normally or parallelly to air stream from a ring of equally spaced holes on the wall.The combustor comprised assemblies of cylindrical and diverging conical sections on which are mounted static pressure taps and thermocouples.The total pressure profiles were measured by a pressue probe rake just downstream of the combustor exit.Each fuel injection persisted about 8 seconds to obtain steady state operiating conditions.The preudo one dimensional flow analysis of supersonic combustor has been improved and employed to yield a description of the bulk processes in the supersonic combustor and to explain the characters of the measured pressure distributions.The results of a series of tests show that the combution efficiency of the transverse injection ahead of a rearward facing step is higher than behind it,and the combustion efficiency of transverse injection is higher than that of the downstream injection,and it is also evident that the total pressure loss is maximum in the case of transverse injection ahead of a rearward facing step and is minimum in the case of parallel injection.