'choking effect with busemann airfoil' simulation project by e0625598


I created a new simulation project called 'choking effect with busemann airfoil':

this simulation predict the hysteresis phenomena when a buseman airfoil will accelerate above the specific choking mach number and decelerate to sub sonic speed.

the simulations will done with rhoCentralFoam with zero viscosity (Euler-Equations)

At first a coarse mesh with around 50k cells is used.

More of my public projects can be found here.


Hi @e0625598!

I would be very interested to see the outcome of your simulations! I looked at some papers and webpages and this is a really interesting topic we could validate here on SimScale.

Have you already had a look at Busemann-Type Biplane for Avoiding Choked Flow? Are you working with some data you are trying to validate?

Looking forward to achieve something nice here and put that in our Project Spotlight section!

All the best!



Hello @jousefm,

i knew this paper. Some years ago, i hold a presentation about “Busemann Biplane and its improvements” at class of Helmut Sobieczky at TU Wien.

But, at first i have to run some simulations about “shock tube” cases, finding the right/stable boundary conditions and appropriate Courant Number for the rhoCentralFoam solver.

With this information it is easier starting a more complicated case.

Best regards


Hi @e0625598!

Do you mind sharing your presentation with me? Feel free to inbox me.

I am keeping an eye on your simulation to see how you are setting it up as I never heard of the Busemann Biplanes before. Please keep me up-to-date and we will hopefully see some nice post-processing results from you soon!

Kind regards,



Hello @jousefm,

i’m sorry but i have not my presentation anymore, but here is excellent short summary of what have been developed until 2010.

Shape Optimization of Busemann-Type Biplane Airfoil for Drag Reduction Under Non-Lifting and Lifting Conditions Using Genetic Algorithms

And short summary:

Kind regards,


Hi @e0625598!

Thanks a lot for the links! Something nice to read for a train ride :wink: Keep me updated!



Hello @jousefm,

is it possible to define some step-function as velocity inlet bc?

there are only some functions implemented:

(sin, exp, tanh, …)

have you an idea how i could realise such a profile:

(i’ve tried it with a combination tanh but that is not exact!)

t u

00 00

05 01

15 01

20 01.25

28 01.25

end so on…


Hi @e0625598!

You can work with a CSV file. My colleague Darren (@1318980) has already posted an answer on this issue: Velocity inlet with CSV.

Let me know if it helped you!