Improved k-ω-γ transition model by introducing the local effects of nose bluntness for hypersonic heat transfer

After considering the local effects of nose bluntness on the transition, a modification for the timescale of the second mode in the three-equation k-omega-gamma transition model has been proposed to improve the hypersonic transition past cones. The ratio of local unit Reynolds number over freestream unit Reynolds number (Re-local/Re-infinity) is introduced to delay and reduce the development of second mode instability, according to the results of linear stability theory. The hypersonic transitions past a cone with three nose radii at the angle of attack of 0 degrees were simulated to calibrate the new model and its constants. Then, the improved model is extended to predict the hypersonic transitions past the cones with larger radius and at non-zero angles of attack. Despite the original model can reflect the transition trend, the improved model performs much better than the original one when comparing with the available measurements. (C) 2017 Elsevier Ltd. All rights reserved.