Compressible Mixing Layers: 2D Model

Virginia Tech

Each frame is a collection of 501 vertical and 129 horizontal node points in an evenly-spaced mesh (node coordinates can be eliminated in this case). The vertical boundaries are periodic in the horizontal direction, hence, the animated movie shown below has been duplicated in the horizontal direction where the vertical center line represents a common boundary. The final frame size is 501 by 258.

Visual Insight:
With the larger frame size, we can more clearly see the reflected shock from the lower boundary. In the same animation we can also see that the shock wave does not originate from poor numerical approximations of the boundary conditions but is the result of an expansion fan formation from a vortice that develops in the mixing layer with time.

(1.5MB)Click on this image to view an animation of shockwave formation. It is interesting to note that in this case the animation best demonstrates the formation of the shock wave by the use of a series of simple countour line plots. Other visual formats such as 2D-color or Gouraud shaded raised surfaces did not show the shock wave as well.