Kinetic description of the turbulence in the supersonic compressible flow over a backward/forward-facing step

• Supersonic turbulent 2D flow over a backward/forward-facing step is modeled.
• The explicit–implicit scheme for the solution of Boltzmann equation is applied.
• The range of leeward-face angle is considered.
• The surface pressure, skin friction and heat-transfer coefficient are shown.
• The comparison with experimental and numerical results is performed.

In the present paper the Boltzmann kinetic equation is applied to investigate a supersonic turbulent compressible flow. For this purpose a numerical simulation of supersonic compressible two-dimensional flow in the vicinity of a backward/forward-facing step with leeward-face angle ranging from 8° to 90° and free-stream Mach number Ma∞ ≈ 3 is carried out. An explicit–implicit numerical scheme in the framework of the direct approach for the solution of the full Boltzmann equation is used. Principal features of the kinetic approach for the description of compressible turbulence are discussed. The comparison with experimental and numerical results presented in the open literature is performed in terms of pressure, skin friction and heat-transfer coefficient distributions over the step surface. Kinetic computed flow field structures for different leeward-face angles are presented and discussed. A good agreement with the experimental results is observed.