学术报告（王春朋 11.28）

abstract：

In this talk, we introduce recent joint works with Professor Zhouping Xin on smooth transonic flows in two dimensional de Laval nozzles, which are governed by a nonlinear elliptic-hyperbolic mixed type equation with degeneracy at the sonic state. For smooth transonic potential flows whose sonic points are all exceptional, it is shown that the existence of such a smooth transonic flow is determined by the geometry and the height of the nozzle at the throat.