PIV Study of Flow Characteristics in a Triangular Duct with InternalRibbed Surfaces

摘要

An experimental study was conducted on turbulent flow in an equilateral triangular duct with ribbed internal surface through Particle Image Velocimetry (PIV) explorations. Square ribs were attached on all three internal surfaces of the triangular duct with an aspect ratio (I.e., the rib size ( e ) to the hydraulic diameter (D)) of e/D=0.18. The development of the turbulence-induced secondary flow at the near wall region of the duct, the detachment and reattachment of the turbulent flow as well as formation of vortex around the rib were analyzed and discussed respectively at a fixed Reynolds number of 20,600. Investigation of the turbulent flow in the triangular duct with smooth internal surface was also performed to study the effects of the internal attached ribs on the duct's heat transfer performance.