what does wall thickness mean when i am modelling a solid cylinder (diameter=0.01) as a wall? Wall thickness is required to carry out Heat Transfer analysis.

wall thickness is used for very thin walls (like sheet metal)....for more description you can refer to fluent user manual....

as you are already modelling solid volume...so I think you may not need to model wall thickness for cylinder..... unless physically you want to specify a thin layer of extra material (different material then solid cylinder) coating on cylinder then you could use wall thickness for this material without creating mesh for this very thin layer.

thanks Umesh but the problem is that the option of wall thickness is already there for the cylinder. fluent only asks me to enter the value of the wall thickness so i cannot turn the option of modelling wall thickness off. plus i am not specifying any thin layer of extra material. maybe i need to specify the dia of cylinder for wall thicknes. what do u say? i have searched the manual but nothing can be drawn regarding wall thickness of a cylinder.

specify 0 thickness...and don't turn it on... In manual search it for wall thickness... http://www.engres.odu.edu/Applicatio...e216.htm#27939

[hamdiengizanganah]

You can model conduction within boundary walls and internal (two-sided) walls of your model. This type of conduction, called shell conduction, allows you to more conveniently model heat conduction on walls where the wall thickness is small with respect to the overall geometry (finned heat exchangers or sheet metal in automobile). Meshing these walls with solid cells would lead to high-aspect-ratio meshes and a significant increase in the total number of cells. See below for details about shell conduction. So no need to mesh the wall.
For example, you can model the effect of sheet metal between two fluid zones, a coating on a solid zone, or contact resistance between two solid regions. FLUENT will solve a 1D conduction equation to compute the thermal resistance offered by the wall and the heat generation in the wall.
To include these effects in the heat transfer calculation you will need to specify the type of material, the thickness of the wall, and the heat generation rate in the wall.
The thermal resistance of the wall is dx/k, where k is the conductivity of the wall material and dx is the wall thickness. The thermal wall boundary condition you set will be specified on the outside of the fluid/solid domain, which is called the inner surface of the thin wall.
I refer you to Ch7 of fluent guide.
I hope to be meaningful for all.