Three dimensional heat transfer modeling of gas-solid flow in a pipe under various inclination angles

•We model three dimensional heat transfer of gas-solid flow in a pipe under various inclination angles.•We use k − τ and kθ − τθ two phase model in a lagrangian/Eulerian four way approach.•We report the dominant effect of pipe inclination angle on the flow field characteristics.•The critical pipe angle based on the maximum pressure gradient and Nusselt number is lower than vertical case.•Increasing loading ratio shifts the optimal inclination angle of maximum pressure drop to the lower amount.

The turbulent heat transfer in gas-solid flows through an inclined pipe under various inclination angles is studied with constant wall heat flux. The hydrodynamic k − τ and kθ − τθ thermal two phase model is used in a lagrangian/Eulerian four way approach. The numerical results agreed reasonably with available experimental data in vertical and horizontal pipe flows. The effects of inclination angles on the flow patterns are reported. The pressure drop and Nusselt number are enhanced significantly as the inclination increases up to a certain angle. The mass loading ratio has influence on the optimal inclination angle. With increasing loading ratio, the optimal inclination angle of maximum pressure drop shifts to the lower amount.

Graphical AbstractThe maximum and minimum Normalized Nusselt number, respectively, occur in inclination of 10° and 90°. With increasing inclination angle from vertical case, the Normalized Nusselt number gradually increases. At z = 1.5 and 2.5, two peaks are observed in all inclinations.Figure optionsDownload full-size imageDownload as PowerPoint slide