Simultaneously measured vorticity and passive heat in a cylinder wake

Abstract

This work is an experimental study of the turbulent vortex structures and heat transport in the intermediate wake of a slightly heated cylinder. The three components of the vorticity vector were measured simultaneously with the fluctuating temperature at nominally the same point over x/d = 10–40 using a 3D vorticity probe and four cold wires. By using phase-averaging analysis, the contribution of coherent motion of various vorticity correlations such as vorticitypassive heat, as well as the velocity–vorticity correlations has been discussed, in conjunction with Reynolds shear stress and heat fluxes. The results indicate that coherent motion contributes significantly to the heat transport within the vortices while the incoherent motion mainly contributes between two vortices. The vorticity–velocity correlation involving spanwise vorticity component mainly contributes to the gradient of Reynolds shear stress.