Meshing in narrow regions
 

In a centrifugal pump, the gap between casing and impellor is very small (about 0.004 inch). In that location, how to mesh by providing atleast 5 or 6 elements? Is it possible to mesh for such small gaps in a big domain?

looking for a kind response

regards satyam

Re: Meshing in narrow regions
 

It depends on what mesher your are using. TurboGrid handles this automatically. CFX-Mesh or ICEM CFD Tetra/Prism will require a large number of elements since they generally create isotropic elements. You can extrude prisms away from the walls, but the prism layers will still have to be connected by tets in between.

I you use Hexa, you can include a block across the tip. I recommend splitting the block down the center, however, and not trying to match up the topology. Making the mesh 1:1 at the tip AND at the periodic interfaces is a big challenge (depending on the type of blade you are meshing of course). Again, TurboGrid does this automatically for you, putting a GGI interface at the tip.

Regards, Robin

Re: Meshing in narrow regions
 

I would like to know if TurboGrid can handel the geometry created not by Bladegen easily, there is lots of work to do before creating a grid

Re: Meshing in narrow regions
 

Turbogrid is not restricted to BladeModeler geometry, but it cannot import CAD models. The geometric input to TurboGrid is three files, one to describe the hub curve, one for the shroud curve and two or more profiles to describe the blade.

Regards, Robin

Re: Meshing in narrow regions
 

is this accurate to define only two profiles for blade ? if it has got some sweeps?

Re: Meshing in narrow regions
 

In some cases, yes, such as a ruled element blade. In most cases you require more than two. Two profiles is simply the minimum that TurboGrid requires.

-Robin

Re: Meshing in narrow regions
 

So, it is required the input files to describe the geometry of the hub,shroud and the blade. For the case of three dimensional blade, I think it is not easy to define the necessary files.Have you tried?

thanks

Re: Meshing in narrow regions
 

These are commonly created by a blade design system. If you don't have one, BladeModeler can also create them. Doing so manually might be a bit more of a challeng.

Regards, Robin