Local convective transfer coefficients in a channel downstream of a partially constricted inlet

Abstract

Experiments have been performed to investigate the transfer coefficient distributions in the regions of flow separation, reattachment, and redevelopment along the walls of a channel whose inlet is partially constricted. The experiments were carried out for Reynolds numbers in the laminar range and utilized the naphthalene sublimation technique with air as the working fluid. The results revealed the presence of a new region of augmented transfer coefficients that is in addition to the zones of augmentation caused by the reattachment of the separated flow. The separated regions on the respective walls of the channel are of different length (i.e. short and long stalls) except at low Reynolds numbers and small constrictions. The new region of augmentation occurs on the wall of the channel that is washed by the short stall and is downstream of both the long and short stall reattachments. There is strong evidence that the new region of augmentation is caused by a vortex street shed from the tips of the constriction plates situated at the inlet.