Experimental investigation on abnormal heat transfer behaviors of hydrocarbon fuel under supercritical condition in a minichannel

The heat transfer characteristics of hydrocarbons in minichannels were studied experimentally, with the heat transfer process divided into four stages: normal heat transfer, heat transfer enhancement, heat transfer weak-ened, and heat transfer recovery. The onset of heat transfer weakened (OHW) in the process was considered, and the corresponding heat flux (qOHW) was defined. The results show that qOHW is related to the inlet enthalpy, Reynolds number, and working pressure. A dimensional prediction formula for the qOHW was proposed based on the supercritical boiling number, ratio of enthalpy difference to enthalpy at pseudo-critical temperature, Rey-nolds number, and dimensionless pressure. The average relative deviation of the correlation was 2.01% compared with the experimental results. This study will contribute to the thermal research on supercritical fluids in a minichannel.