Numerical investigation on flow and heat transfer characteristics of supercritical RP-3 in inclined pipe

Numerical simulations of flow and heat transfer to supercritical RP-3 through the inclined tubes have been performed using LS k–ε model embedded in Fluent. The physical properties of RP-3 were obtained using the generalized corresponding state laws based on the four-component surrogate model. Mass flow rate is 0.3 g/s, system pressure is 3 MPa, inlet temperature is 373 K. Inclination of the inclined pipe varied from −90° to 90°, with heat flux varied from 300 kW/m2 to 400 kW/m2. Comparison between the calculated result and the experimental data indicates the range of error reasonable. The results of ±45° show that temperature inhomogeneity in inclined pipe produce the secondary flow in its cross section due to the buoyancy force. Depending on the strength of the temperature inhomogeneity, there will be two different forms of secondary flow and both contribute to the convective heat transfer in the pipe. The secondary flow intensity decreases when the inhomogeneity alleviates and thermal acceleration will play a leading role. It will have a greater impact on the turbulent flow to affect the convective heat transfer in the pipe. When changing the inclination, it affects the magnitude of the buoyant component in flow direction. The angle increases, the buoyancy component decreases. And the peak temperature of wall dominated by the secondary flow will move forward and increase in height. Keywords: Heat transfer, Hydrocarbon fuel, Inclined pipe, Supercritical pressure, Variable properties