Experimental study on the thermodynamic characteristics of the high temperature hydrocarbon fuel in the cooling channel of the hypersonic vehicle

摘要

Cooling is one of the key technologies for the scramjet considering the enormous thermal load and the demand of reusable long-range mission. In the regenerative cooling process, hydrocarbon fuel flows through the cooling channel, gets heated and experiences severe thermal properties changes. The compressibility of fuel becomes non-negligible and possible dynamic process emerges, which affects both the characteristics of fuel cooling and fuel mass flow control. As a result, the dynamic characteristics of the high temperature hydrocarbon fuel within the cooling channel must be carefully studied. In this work, experiments are conducted at different simulated engine working conditions. The settling time of pipe pressure drop is used to characterize the dynamic process of the outlet fuel mass flow, because the outlet temperature of the fuel is too high to measure the fuel mass flow directly. In conditions of the variation of inlet fuel mass flow and backpressure disturbance, overshoot of the pressure drop is observed and the magnitude of which varies with the working conditions. The settling time of outlet fuel temperature and wall temperature channel firstly increases, then decreases with the increase of the outlet fuel temperature. The settling time of both outlet fuel temperature and wall temperature increases with the increase of the heating heat flux. The experimental results in this work are expected to provide supports to the engine control system design.