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airfoil modeling

MohammadHasan Khaliji Oskouei

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Hi
I am trying to modeling the flow separation from the airfoil (NACA0015) by Comsol 3.5a. after I click on the solve bottom show the error as below:

Error: 6170
Failed to evaluate variable.
- Variable: T
- Geometry: 1
- Subdomain: 1
Failed to evaluate variable.
- Variable: rho_ns
- Defined as: ((unit_kg_cf*mat1_rho((T/unit_K_cf)))/(unit_m_cf^3))
Failed to evaluate expression.
- Expression: nojac(rho_ns)
Failed to evaluate expression.
- Expression: d((((nojac(rho_ns)*((nojac(u)*vx)+(nojac(v)*vy)))+py)-(nojac(eta_ns)*((vxx+uyx)+(vyy*2)))),vy)

I attach the comsol file by this message.
If would possible to everyone to help me to solve this problem.
hasan


1 Reply Last Post 11 juil. 2010, 14:36 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 11 juil. 2010, 14:36 UTC−4
Hi

I do not have V3.5 accessible, but I'm pretty sure you have added soem "air" from the material database, and have not checked which variables are required to fully define the material.

Try to add a Constant T=20[degC] and p=1[atm], to be sure yourt materials are fully defined (adapt to your temperature and pressure).

Good luck
Ivar
Hi I do not have V3.5 accessible, but I'm pretty sure you have added soem "air" from the material database, and have not checked which variables are required to fully define the material. Try to add a Constant T=20[degC] and p=1[atm], to be sure yourt materials are fully defined (adapt to your temperature and pressure). Good luck Ivar

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