Heat transfer and structure of pulsating flow behind a rib

Abstract

The paper elaborates on experimental studies of heat transfer and kinematic structure of steady and pulsating air flows past a spanwise rib. The forcing frequency range of (0–30) Hz is considered, and the normalized forcing amplitude of velocity is 0.5. Forced flow pulsations are shown to enhance heat transfer if compared to the steady-state flow, particularly in the near-wake region behind the rib. Experimental data on the heat transfer coefficient in pulsating flows are best generalized using the non-dimensional pulsation frequency (Strouhal number). Profiles of velocity and turbulent parameters are demonstrated at a number of representative coordinates along the separation region. The dynamics of the kinematic structure of pulsating flows is described using the profiles of parameters in different phases of forced flow pulsations. The correlation between local heat transfer in the separation region and local hydrodynamic parameters is analyzed. The distribution of heat transfer coefficient over the wall in the rib wake correlates best with the distributions of transverse velocity component.