Regarding Y+
hi friend i have one doubt where i have to give the value of y + in starccm during simulation

Hey there,
As I understand it, you control your Y+ by the prism layer meshing settings. There you can specify 1st wall thickness, total boundary layer thickness, number of cells etc. These, as you know from your aerodynamics theory,then control your Y+. If you want a more detailed explanation, let me know and I can supply you with the equations or links to them. Hope this helps. 
hi aerospaceman,
I am wondering how to figure out the boundary layer thickness for a nozzle flow. Could you give me a detailed explanations, if possible with equations. 
How to control the y+ value in StarCCM+ ?
Quote:
I've been working with StarCCM+ V3.06. I would like to know how to estimate the y+, as you said by using "prism layer mesher" right? so could you tell me more clearly? thanks in advance! email: trieuckgt@gmail.com MSN: trieu.dut@livemail.com YM: trieu_tme@yahoo.com 
Hi
i'm not sure, if i've understood your problem the right way. A good estimation for the near wall prism layer of a flat plate could be found by using the tool on http://geolab.larc.nasa.gov/APPS/YPlus/ . I'm doing simulation on an airfoil, so i specify the near wall prism layer thickness, using the value calculated by this tool, and it works very well. After the simulation, you should do a scalar plot of the y+ value and adjust the near wall prism layer thickness if the y+ does not meet the requirements. greetings 
Quote:
Many thanks Asherah 
The output is the thickness of the first layer. For CCM you must calc it with the stretching factor and the numbers of layer.

Y+ Calculator
Hi Folks,
I don't know if you noticed, but CFDOnline has it's own Y+Calculator! It's very handy and gives you the near wall thickness as an ouput for your desired Y+value. It also gives a link to the wiki, where the formulas are explained in detail. 
All times are GMT 4. The time now is 20:00. 