Parametric analysis of entropy generation in turbulent convective forced flow in spiral channels at constant wall temperature

Abstract

This paper discuses parametric analysis of entropy generation in a forced convective turbulent flow of an incompressible fluid at a constant wall temperature through spiral channel of rectangular cross section of flow path has been carried out in terms of mass flow rates, temperature differences between fluid flow and temperature of the wall of the passage surface, width of the spiral passages and the shape geometry, as well as the types of fluids. Air is used as the working fluid, and in addition, water and oil are used in the parametric study. The competition between heat transfer enhancement and entropy generation has been addressed. Comparison between entropy generation profiles for different passage widths and shapes have been reported. It is found that mass flow rate and inlet fluid temperature have a considerable impact on entropy generation and hence on heat transfer enhancement. The findings show that the narrowing passage consumes more pump power to overcome viscous dissipation. Regarding the channel shape, it was found that the rectangular channel has the highest Bejan number (Be), while the circular spiral channel requires more pump power than the others. The data obtained indicate that the selection of the most suitable configuration and the best flow conditions becomes a critical task. Also, secondary flow due to centrifugal force and curvature has a significant effect on increasing heat transfer and entropy generation.