A ghost-cell immersed boundary method for large-eddy simulations of compressible turbulent flows

Abstract

A methodology to perform a ghost-cell-based immersed boundary method (GCIBM) is presented for simulating compressible turbulent flows around complex geometries. In this method, the boundary condition on the immersed boundary is enforced through the use of ‘ghost cells’ that are located inside the solid body. The computations of variables on these ghost cells are achieved using linear interpolation schemes. The validity and applicability of the proposed method is verified using a three-dimensional (3D) flow over a circular cylinder, and a large-eddy simulation of fully developed 3D turbulent flow in a channel with a wavy surface. The results agree well with the previous numerical and experimental results, given that the grid resolution is reasonably fine. To demonstrate the capability of the method for higher Mach numbers, supersonic turbulent flow over a circular cylinder is presented. While more work still needs to be done to demonstrate higher robustness and accuracy, the present work provides interesting insights using the GCIBM for the compressible flows.

Keywords:

• immersed boundaries
• ghost cells
• compressible flows
• LES
• wavy surface
• flow over a cylinder

Acknowledgements

The parallel computation involved in this work was made possible by the facilities of the Shared Hierarchical Academic Research Computing Network (SHARCNET).

Additional information

Funding

The financial support for this work was provided partially by the National Science and Engineering Research Council of Canada (NSERC) and Bombardier Aerospace through the NSERC Industrial Postgraduate Scholarships (IPS) Program.