how I know drag force, downforce, drag coefficient and lift coefficient from CFD analysis in Hyperworks CFD?

Kesit Bayu

Hi, my name is Kesit Bayu

I have finished the analysis in Hyperworks CFD, but I still don't know how I can find the drag force, drag coefficient, lift force and lift coefficient, where can I find all of that? I use Hyperworks CFD 2020.1

thanks for your attention

best regards

Kesit

acupro

With the 'Plot' tool from HyperWorks CFD you can create plots of the integrated force components (x/y/z) for the surfaces of interest.  From there you could export the data for further analysis - calculate lift/drag/coefficients.

From the AcuSolve Command Prompt, you may also find  acuLiftDrag  useful.  As usual, add the  -h  to see the usage.

Kesit Bayu

thanks for your answer

If I use a plot from HyperWorks, can I know immediately how much lift / drag force / coefficient or do I need to do further calculations to find out the lift / drag force / coefficient?

acupro

Kesit Bayu said:

thanks for your answer

If I use a plot from HyperWorks, can I know immediately how much lift / drag force / coefficient or do I need to do further calculations to find out the lift / drag force / coefficient?

From the Plot function you can get the integrated force components in the x, y, and z directions.  If those are the directions of interest, then one of those would be lift and one would be drag - assuming the output surfaces are defined according to what you want for your lift/drag calculations.  Beyond that, the lift and drag coefficients would need to be computed separately, as they will depend on your definition for those - typically including projected area, reference velocity, reference density - along with the computed lift and drag themselves.

acuLiftDrag is probably suited mostly for wing profiles at different angles of attack - so it depends on what is your geometry, whether or not that script will be useful for you.

Kesit Bayu

thanks for your answer sir, it is very helpfull

i tried to read the result by looking with hypergraph, is the traction in this case a force acting on a component?

and one thing that I am still confused about is that there is a time variable in the results, and each time it has different traction results,

how can I conclude how much drag / lift force occurs on a component with some data at a time? do i have to average it to find out how much force is acting on a component?

best regards

Kesit

acupro

Kesit Bayu said:

thanks for your answer sir, it is very helpfull

i tried to read the result by looking with hypergraph, is the traction in this case a force acting on a component?

and one thing that I am still confused about is that there is a time variable in the results, and each time it has different traction results,

how can I conclude how much drag / lift force occurs on a component with some data at a time? do i have to average it to find out how much force is acting on a component?

best regards

Kesit

Correct - if you're looking at surface integrated data, the integrated traction values are the forces - and they would typically be separated into X, Y, and Z components of traction/forces.

By default, the integrated values are written at each time step, so you'll see the results at each time step.  If the values have stabilized by the end of the simulation, that's an indication you may have reached a steady-state solution, and the final value should be fine, or averaged over the last few time steps if the oscillation in values is small.

If the resultant values are still changing a lot, then maybe the solution is really transient, and there is no steady-state solution.

Kesit Bayu

thanks for your answer sir, it is very helpfull, it turns out that the answer I was looking for was answered here

best regards

kesit