Experimental study of flow distribution for aviation kerosene in parallel helical tubes under supercritical pressure

Abstract

Experiments on flow distribution for supercritical jet fuel RP-3 in parallel helical tubes were conducted. A heating and energy balance method is proposed to test the flow mass rate in two branches. The flowing RP-3 is stressed from 3 MPa to 5 MPa and the total mass flow rate fixed to 4 g/s. Two identical parallel helical tubes were set by connecting headers and the flow direction was arranged in Z-type. The helical tubes have curvatures of 0.045, 0.06 and 0.09 with same pitch. Effects of heat flux, system pressure, heat flux inhomogeneity and helical curvature for flow distribution are analyzed through the various experiments. Also, the flow distribution calculation variation is obtained to compare to the experimental results. The results indicate that the flow mal-distribution is easy to happen at the pseudo-critical point as the thermal properties have serve changes. The flow distribution deviation between the two helical tubes is less than 0.5% when the system pressure reaches 2.09 times of critical pressure and the helical curvature can influence the flow distribution significantly. Furthermore, the calculated results can distinctly match the experimental due to the fuel density variation model.