Heat transfer enhancement by Gِrtler instability

Measurements of mean velocity field and mean temperature field were performed in a concave boundary layer. The growth of the induced Gِrtler vortices embedded in this boundary layer has been determined in two ways by a criterion based equally on spanwise distortion of velocity or temperature profile. The streamwise and spanwise evolution of heat transfer coefficient has been determined by measurement of wall temperature. It was found that the steady growth of these structures induces a characteristic plateau in the evolution of Stanton number versus Reynolds number. This plateau starts with the enhancement of the amplification criterion and finishes when the transition occurs.