Transition prediction for supersonic and hypersonic boundary layers on a cone with angle of attack

Transition prediction for boundary layers has always been one of the urgent problems waiting for a solution for the development of aero-space technology,yet there is no reliable and effective method due to the complexity of the problem.The eN method has been regarded as an effective method for the transition prediction of boundary layers.However,it heavily relies on experiment or experience.And in cases with three-dimensional base flow,for instance,the boundary layer on a cone with angle of attack,the result of its application is not satisfactory.The authors have found its cause and proposed the method for its improvement,which did yield the fairly satisfactory result for a given test case,and also did not rely so much on experiment or experience.However,before people can really apply this method to practical problems,more test cases have to be studied.In this paper,more test cases for the application of the improved eN method to problems of transition prediction of supersonic and hypersonic boundary layers on cones with angle of attack will be studied.The results are compared with those obtained by experiments and/or direct numerical simulations,confirming that the improved eN method is effective and reliable.We also find that there may be more than one ZARF for each meridian plane,and which one should be chosen for the eN method has been clarified.