Turbulent Flow and Heat Transfer Characteristics around a Square Prism in a Boundary Layer

The characteristics of turbulent flow and heat transfer around a square prism in a turbulent boundary layer have been experimentally investigated, which simulated one of the ribbing inside the ribbed tubes for an enhancement of heat transfer in a heat exchanger. Three-dimensional flow measurements were performed by combining a 2-color 4-beam LDV and a conventional 2 beam LDV probes which were miniaturized by using optical fibers. Local flow characteristics such as the mean velocity and turbulence intensity in three components were presented to clarify the flow behavior. The heat transfer coefficient has a peak value behind the rib near the reattachment region. It has been pointed out from the results that the feature of heat transfer coefficient was closely related to the turbulent flow characteristics.