values of turbulent intesnsity

February 19, 2009, 06:20

1.what value of turbulent intensity should be given at inlet (far field) and opening (enclousre) which is atmosphere for an external aerodynamics problem in CFX Pre forhigh subsonic flow (0.7 Mach) 2. what should be dimesions of enclousre used for far field simulation if air vehcile is a cylinder of Lenght = L and Diameter D. boundary conditions are to be given at enclousre inlet an outlet

February 24, 2009, 16:31

Hi,

1. Inlet turbulence = whatever intensity is present in the inlet in the real device. If it is high subsonic flow then I guess the ambient turbulence levels are quite low, so try 0.01% or something like that. The experimental results you are comparing to should report the ambient turbulence level. If you don't have a number to start with then assume 0.01% and do a sensitivity analysis on it too see if the exact value is important.

2. Problem dependent. Do a sensitivity analysis and find out.

Glenn Horrocks

February 19, 2009, 06:20	values of turbulent intesnsity	#1
Tanveer Ahmad Rubani Guest Posts: n/a	1.what value of turbulent intensity should be given at inlet (far field) and opening (enclousre) which is atmosphere for an external aerodynamics problem in CFX Pre forhigh subsonic flow (0.7 Mach) 2. what should be dimesions of enclousre used for far field simulation if air vehcile is a cylinder of Lenght = L and Diameter D. boundary conditions are to be given at enclousre inlet an outlet

February 24, 2009, 16:31	Re: values of turbulent intesnsity	#2
Glenn Horrocks Guest Posts: n/a	Hi, 1. Inlet turbulence = whatever intensity is present in the inlet in the real device. If it is high subsonic flow then I guess the ambient turbulence levels are quite low, so try 0.01% or something like that. The experimental results you are comparing to should report the ambient turbulence level. If you don't have a number to start with then assume 0.01% and do a sensitivity analysis on it too see if the exact value is important. 2. Problem dependent. Do a sensitivity analysis and find out. Glenn Horrocks

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