[sampathevs]

Can anyone please help me in creating a aerodynamic wing in GAMBIT.
I know how to create a airfoil, but I'm not getting any idea in this wing geometry.

[Far]

use net surface command. steps are :

1. create airfoils at different locations along span
2. for circular te and le, use nurbs command to create four surfaces a)le b) upper surface c)lower surface d) te
3. if trailing edge is flat then join the two points on upper and lower surface with straight line.
4. create four splines (nurbs) through the corresponding end points of each airfoil on leading edge, upper surface, lower surface and trailing edge.
5. now select the u and v edges in net surface command. select u edges as all airfoil edges on upper surface and v edges (two edges for each segment) which are passing through all airfoils. repeat this for lower surface, le and te.

Thats it.

[ershad]

hi
how can I make an open shell (Cube) in gambit?
the fluid goes out from the upper face and I don't want to define any boundary conditions on the upper face.
can I create a face close to the upper face of Cube and then subtract them?
so the upper face is very thin but the cube is open from top

[Far]

Procedure is same for open or closed cube. For closed cube, the boundaries are walls and for open cube you may define it as inlet or outlet, whatever is applicable in your case

[ershad]

Dear Far
Thank you very much for your reply.
I would be grateful if you could help me more.
I am simulating a membrane bio-reactor. My reactor has 2 main volumes (Attached file). I subtracted smaller volume from the other, but I retained the subtracted volume.
I have defined 3 boundary conditions as follow:

1. Velocity Inlet (flow of air) : the lower face of smaller volume
2. Pressure outlet: the upper face of bigger volume: it is open to atmosphere.
3. ???I don't know how to define the boundary condition of the upper face of smaller volume. In reality the smaller volume is open from top and the air rise up in the smaller volume and goes out from top of it and enters the bigger volume, At initial, the reactor is full of water and its volume fraction is 1.
I have tried some boundary conditions for the upper face of smaller volume(face2), but I encountered ERRORS as follow:

1. OUTFLOW: "Warning both outflow and and pressure boundaries are present in the domain. This is an incompatibility and solution cannot proceed until this is fixed."

2. INTERIOR: "Error: Cannot change face2 to interior because there is only one adjacent cell thread."

3. INTERNAL: "Error: Cannot change face2 to interior because there is only one adjacent cell thread."

What can I define the boundary condition of that face?
Sincerely yours,
Ershad