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HiFiLES / HiFiLES-solver

High Fidelity Large Eddy Simulation Solver
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Should I change Fluid Parameters? #105

Closed popstar0426 closed 8 years ago

popstar0426 commented 8 years ago

Hi: I noticed Fluid Parameters in the input file: Fluid Parameters •gamma: Ratio of specific heats ◦1.4 by default •prandtl: Prandtl number ◦0.72 by defult •R_gas: Ideal gas constant (J/kg-K) ◦286.9 by default •mu_gas: Dynamic viscosity (kg/m-s) ◦1.827E-05 by default •S_gas: "S" from Sutherland's Law for viscosity ◦120 by defult •T_gas: Temperature of the gas for Sutherland's Law (Kelvin) ◦291.15 by default •fix_vis // 0: Sutherland's law, 1: Constant viscosity ◦0 | Sutherland's Law [default] ◦1 | Constant viscosity

Consider the wing in air with altitude 20km, should I change these parameters for a new simulation?

Best regards! Yue

mlopez14 commented 8 years ago

How do the density, dynamic viscosity, and temperature of air change as you go high up in the atmosphere?

popstar0426 commented 8 years ago

I am not sure the Sutherland's law works. May I set Constant viscosity instead? I can check the air parameters from "Data come from U.S. Standard Atmosphere, 1976" and get the Dynamic viscosity. I found taht Sutherland's law coefficients in HiFiLES are quite different from them in this website http://www.cfd-online.com/Wiki/Sutherland_law