Ciao, I'm a student of mechanical engineering, I'm developing a thesis on CFD for ship.I'm using Fluent for a viscous analysis of a Wigley hull. I've noted that Fluent excluded hydrostatic head rho*g*z from the pressure calculation when the density is uniform (user's guide 6-18). If this is unimportant for incompressible gas,it can be a great error for my type of analisys? How am I able to overcome this problem? Maybe by user defined functions (I don't know to compile it), or by a boundary condition? Can this problem invalidate viscous resistance calculation? If you can, send to me a possible solution. Thank you very much.

Giovanni

(1). Interesting question. Can a ship still float without rho*g*z ?

Hi, although it appears as if the hydrostatic pressure is not included in Fluent it actually is! The trick is, that p_hyd is excluded from the pressure-calculation and included in the bodyforce term. That is alright, since p_hyd = rho * g * h it does not change in an incompressible flowfield. If you want to display p_hyd for postproc-reasons than just define a custom-field function under Fluent's "Define"-Menue.

Greetings Detlef