Flow over a backward facing step

The backward facing step flow project was performed as a part of skill lync challenge.

The simulation was performed on three base grid sizes:

1. 3e-4m

2. 2.5e-4m

3. 2e-4m

The above grid sizes were chosen due to lack of computation power.

The Results and findings of the simulation are as follows:

1. Velocity

The Velocity contours obtained in all the three cases are identical. The velocity magnitude plots at the outlet are also identical. They only have a single difference i.e. the curve becomes more and more smooth as we refine the grid which can be explained on the basis that as we refine the mesh size, the space between two nodes in the domain decreases and the curve becomes more smooth.

The contours and plots for the three cases are given:

3e-4m:

2.5e-4m:

2e-4m:

2. Static Pressure

The Pressure contours obtained are also identical in all the three cases. When we plot the Static Pressure magnitude along the length of the step, we see that the curve gets a sudden fluctuation near the part where the cross section of the step increases. When we refine the grid successively we see that this fluctuation converts into a sharp increase in pressure near that part and it gets more pronounced.

The contours and plots for the three cases are given:

3e-4m:

2.5e-4m:

2e-4m: