Convective heat transfer and flow resistance characteristics of supercritical pressure hydrocarbon fuel in a horizontal rectangular mini-channel

Abstract

An experimental investigation on convective heat transfer and flow resistance characteristics of hydrocarbon fuel RP-3 in a horizontal rectangular channel (cross-section flow area of 2.05 × 2.05 mm) at supercritical pressures is reported in this study. The adiabatic friction pressure drop was studied at pressures of 3–5 MPa and fluid temperatures of 350–750 K, covering the Reynolds number range of 866–29,783. The experimental friction factor profile was compared with the theoretical correlations and the transition Reynolds number range was determined. Convective heat transfer characteristics in the electrically heated channel were studied at the mass flux of 162 kg m−2 s−1, with system pressure, inlet fluid temperature and wall heat flux ranging of 3–5 MPa, 395–620 K and 50–103 kW m−2, respectively. The Reynolds number ranged from 938 to 5823. The effects of operating parameters on convection heat transfer in the laminar and transition flow regimes were studied. The non-uniform wall temperature distribution on the channel cross-section indicated that the buoyancy effect should be considered with care in the studied conditions. The applicability of three available buoyancy criteria for horizontal flows was examined in predicting the trends of buoyancy effect at varying operating conditions. In addition, new Nusselt number correlations were developed based on the experimental data for the laminar and transition flow regime, respectively.