Single-phase thermal and hydraulic performance analysis of a V-pattern dimpled obstacles air passage

Abstract

ABSTRACTThis work deals with the experimental investigation on heat transfer, friction factor, and thermal hydraulic performance of V-pattern dimpled obstacles in an air passage. The experiments were conducted in a turbulent flow regime with Reynolds number ranging from 5,000 to 17,000 using air as the working fluid under uniform wall heat flux boundary condition. The experimental investigation encompassed the geometrical parameter, namely relative dimpled obstacles width varying from to , ratio of dimpled depth to print diameter () from 0.50 to 2.0, relative dimpled pitch () from 8.0 to11.0, relative dimpled height of 0.037, and the angle of attack () varying from 35° to 75°. The experimental results revealed that both heat transfer and friction factor of the air passage fitted with the V-pattern dimpled obstacles were significantly higher than those of the smooth-surface air passage. The optimum data of thermal and hydraulic performance were obtained at , 1.0, = 9.0, = 0.037, and = 55°. The current study shows that the thermal hydraulic performance of multi-type V-pattern dimpled obstacles shape is around 7% higher as compared to other obstacles shapes air passage.