A new shock-fitting technique for 2-D structured grids

In the past years, the development of structured shock-fitting techniques dealt with two main problems: the handling of a moving discontinuity on a fixed background grid and the capability of simulating complex flow configurations. In the proposed work, the authors present a new shock fitting technique for structured solvers able to overcome the limitations that affected the approaches originally developed, such as the boundary shock-fitting and the floating shock fitting. Specifically, the technique presented herein removes the strong link between grid topology and shock position, which characterizes boundary shock-fitting methods, and reduces significantly the expensive coding effort for implementing floating shock-fitting methods. In particular, three different test-case, which also deal with mutually interacting discontinuities, are deeply discussed and analyzed. Finally, a global grid-convergence analysis has been performed to quantitatively measure discretization errors and order-of-convergence of the proposed numerical approach.