[Puigar]

Dear community,

I am a newbie of this forum.

I am working on a 2D developed laminar flow (Re 100) in a channel and a square cylinder as an obstacle. Simple stuff

I want to calculate de drag coefficient and the peak-to-peak lift coefficient, so which is the best strategy to calculate it?

I am actually trying to calculate it with immersed surface method regarding the stress and normal tensors and pressure, but the results I get do not match with bibliography.
I use as planform area the length of the square which is facing the flow. dynamic pressure also is easy to get.

Can someone explain how to calculate the lift and drag forces in a simple way for these conditions??

Thank you in advance

[AdvancedSimulation]

Hi @puigar


Did you manage to solve it? I am running the same simulation as you did but on a circular cylinder in my own in-house solver. I am using the momentum exchange method with bounce-back (just f=-f_opp) in LBM with SRT and every time I change the number of lattices in x or y direction, the lift and drag plots vary (especially in terms of the period of the oscillation, which i.e. seems to be doubled if number of y-lattices is doubled).


My deltax=deltay=deltat=1, and I made it dimensionless with Cd=Fx/0.5*U^2*D and Cl=Fy/0.5*U^2*D, and the proportion of the domain is kept as so I do not understand why my Cl and Cd have such changes.


Did you have the same problem?



Best regards & many thanks

[dkl26945]

Originally Posted by Puigar

Dear community,

I am a newbie of this forum. shell shockers online

I am working on a 2D developed laminar flow (Re 100) in a channel and a square cylinder as an obstacle. Simple stuff

I want to calculate de drag coefficient and the peak-to-peak lift coefficient, so which is the best strategy to calculate it?

I am actually trying to calculate it with immersed surface method regarding the stress and normal tensors and pressure, but the results I get do not match with bibliography.
I use as planform area the length of the square which is facing the flow. dynamic pressure also is easy to get.

Can someone explain how to calculate the lift and drag forces in a simple way for these conditions??

Thank you in advance

In this example, the lift force acting on the wing is approximately 304.375 N, and the drag force is 24.35 N.

Remember that the actual values of the lift and drag coefficients (
𝐶
𝐿
C
L
​
and
𝐶
𝐷
C
D
​
) depend on the specific shape and orientation of the object, and they can be found in reference tables or determined through experimentation.