hydraulic diameter in 2d
 

hi all
i am working on a 2D case of the fluidization of charcoal. In order to specify the turbulance specification at velocity inlet, i have to specify the value of hydraulic diameter. In 3d, inlet is a circular duct. Problem is that how i can define the hydraulic diameter for 2D case at velocity inlet edge.

In the tutorial 01 of fluent6.2, i have found that the wetted perimeter will always be 2 for a circular inlet in 2D case regardless of whatever is inlet diameter. Also the hydraulic dimeter will be 2 times the diameter of the circular inelt.

In some other tutorials, i found that the hydraulic diameter will be double of actual diameter for a 2D case.

plz guide me that how this hydraulic dimeter will be double for a 2D case and how this wetted perimeter is 2.

regards

Ahsan

Hello ahsan

to specify turbulence correctly at inlets using intensity and hydraulic diameter you always have take the actual, physical dimensions. If your inlet geometry is a circle then take its diameter, no matter if you are using a 2-D or 3-d model to simulate the problem.

cheers

hi coglione
thanx for guidence

ahsan