[GAMBIT] Meshing a wing with multiple volumes in domain

makaero · February 26, 2010, 13:54

Hi

I am having hard time to mesh a wing with sinusoidal LE. Since i need a fine mesh to predict Cd, i am trying to create small volumes around the boundary and mesh it, then mesh the entire domain.
but its really challenging to do as i am not aware of complete software Gambit.

I will be thankful if someone could help in dividing the volume and mesh the wing. i am running out of time.....

Thanks a lot!

-mAx- · March 1, 2010, 01:55

First try to create a volume surrounding your wing.
Use it to split your domain.
Mesh this new volume (it should be a fine mesh around your wing)
Mesh the other volume with a size function.
If it is not successfull, post a picture

makaero · March 2, 2010, 21:20

Thanks for the reply sir,

As you said i have done two small volumes around the wing (pictures posted)
and meshed those volumes.

now i am working on the domain, if i have to create a C-grid type domain

can i mesh its faces with tri-pave and use cooper mesh to fill it with Tetra hedral cells?

And my wing dimensions are 1m in chord and 1m in span, im using the symmetry BC at root and tip of wing, does it predict correct drag or should i leave free at root of the wing?

-mAx- · March 3, 2010, 01:51

I would do more splits around the wing (especially at leading and trailing edges), enabling map schema (like your second surrounding volumes) instead of pave schema.
Regarding Cd coefficient, Fluent computes all the forces and moments on the body, Cd is computed from the right force and reference values, that you should give. So in your case, give the right reference values according to your geometry (incl. symmetry)

makaero · March 3, 2010, 12:24

A Simulation was run with coarse mesh (using adaptive grid around the wing)
with steady solver and Spallart-Allmaras model

but at high AoA solution is not converged and drag is over predicted, so im trying to do fine mesh around wing.

Since span and chord are in 1m and im using symmetry BC at both ends i consider the wing AR = 2.

Reference values i used in my case:
Area: 1
Density: 1.225
Enthalpy: 0
Lenght: 1
Pressure: 0
Temp: 288.16
Velocity: 83.24
Voscosity: 1.7894e-05
Ratio of sp.heat: 1.4

Do i need to use Unsteady solver for high AoA for solution to be converged?

Thanks a lot.

February 26, 2010, 13:54	Meshing a wing with multiple volumes in domain	#1
makaero Member ANIL Join Date: Apr 2009 Posts: 35 Rep Power: 17	Hi I am having hard time to mesh a wing with sinusoidal LE. Since i need a fine mesh to predict Cd, i am trying to create small volumes around the boundary and mesh it, then mesh the entire domain. but its really challenging to do as i am not aware of complete software Gambit. I will be thankful if someone could help in dividing the volume and mesh the wing. i am running out of time..... Thanks a lot!

March 1, 2010, 01:55		#2
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	First try to create a volume surrounding your wing. Use it to split your domain. Mesh this new volume (it should be a fine mesh around your wing) Mesh the other volume with a size function. If it is not successfull, post a picture __________________ In memory of my friend Hervé: CFD engineer & freerider

March 3, 2010, 01:51		#4
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	I would do more splits around the wing (especially at leading and trailing edges), enabling map schema (like your second surrounding volumes) instead of pave schema. Regarding Cd coefficient, Fluent computes all the forces and moments on the body, Cd is computed from the right force and reference values, that you should give. So in your case, give the right reference values according to your geometry (incl. symmetry) __________________ In memory of my friend Hervé: CFD engineer & freerider

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March 3, 2010, 12:24		#5
makaero Member ANIL Join Date: Apr 2009 Posts: 35 Rep Power: 17	A Simulation was run with coarse mesh (using adaptive grid around the wing) with steady solver and Spallart-Allmaras model but at high AoA solution is not converged and drag is over predicted, so im trying to do fine mesh around wing. Since span and chord are in 1m and im using symmetry BC at both ends i consider the wing AR = 2. Reference values i used in my case: Area: 1 Density: 1.225 Enthalpy: 0 Lenght: 1 Pressure: 0 Temp: 288.16 Velocity: 83.24 Voscosity: 1.7894e-05 Ratio of sp.heat: 1.4 Do i need to use Unsteady solver for high AoA for solution to be converged? Thanks a lot.