Subsonic solutions to compressible transonic potential problems for isothermal self-similar flows and steady flows

摘要

We establish boundary and interior gradient estimates, and show that no supersonic bubble appears inside of a subsonic region for transonic potential flows for both self-similar isothermal and steady problems. We establish an existence result for the self-similar isothermal problem, and improve the Hopf maximum principle to show that the flow is strictly elliptic inside of the subsonic region for the steady problem. (c) 2006 Elsevier Inc. All rights reserved.