[EternalSeekerX]

Dear fellow forum mates,

I am currently doing a project for my 4th year CFD course. My problem statement is a turbulent flat plate. My simulation is based off of the NASA turbulent flat plate.

Nasa Website: http://www.grc.nasa.gov/WWW/wind/val.../fpturb02.html

Now I need some help in finding out where my error lies since after ever single run my skin friction vs reynolds number doesn't match Weigarts Data.

So let me outline what I have done.

For the geometry I decided to draw a box, my initial points (In a XYZ co-ordinate system) is (-0.5x0x0) and my final point is (5.09016x0.328x0.00109). The co-ordinates are in meters. I then used the imprint feature to imprint two surfaces both with a length of 0.5m on the XY and XZ plane to divide the plate up.

Next for meshing I used CFX-Mesh and used edge sizing and bias factors to get a mesh distribution. I used mapped face meshing as well. For the two top edge I set the number of divisions to 200 while for the sides I set the number or divisions to 160 while setting a bias factor of 90. I used named selection, I set the left side edge as an inlet, right side as an outlet, both faces as symmetry, the bottom edge as inviscid for the first 0.5m and viscous for the rest. The top edge was just named top.

For the set-up I set the inlet with the following values: Ux=68.8m/s, k=23.6 and omega=12.83. For the outlet I set it as pressure outlet with the relative pressure as 14.7psi. I set the inciscid as a free slip wall and the viscous as a no slip wall. The faces were set as a symmetry boundary. I am having trouble setting the top edge as I have tried to set it as a free slip wall and even as a symmetry BC but It doesn't change my values. The website sites the top as a freestream BC but I don't know what I should set that in Ansys as. I am using SST for the solving method with a rms of 1x10-6. The operating pressure and temperatures were set as the freestream values of 14.7psi and 540R.

For cfx post I created a velocity vector along the symmetry plane and a pressure countour as well. From the pressure and velocity contours everything seems fine. I drew a line at the outlet and ploted a velocity vs y graph. I then drew a line across the plate where I set my wall. I used custom functions to get values for Cf (using Tau) and Re. But unfortunatly I am still off by a decent margin. At Re 0 Weigart has a CF of 0.5 or so I am getting 0.3, the curve matches perfectly though.

Any help would be appreciated.

Thanks