help with advection-diffusion equation

sambatra · August 7, 2009, 03:18

Hi there,
I'm solving an advection-diffusion equation(temperature equation) but it always crashes!!!
Is it possible to solve an advection-diffusion equation?How?
Can somebody out there help me please?
Best Regards.

titio · August 7, 2009, 11:15

Hi,

What are the boundary conditions, methods used, and other relevant information. Yiu have to give more information, otherwise I will not be able to help you.

Regards,

Titio

sandy · August 8, 2009, 06:18

Hi Titio, could you help me too? I want to simulate the true pressures in the domain but not some relative pressure values. What boundary conditions I should give. I gave a fixValue in inlet and a zerogradient in outlet, but the results are wrong. By the way, my problem is turbulence flows. Thanks a lot.

sambatra · August 11, 2009, 05:54

Hi
Sorry for the delay in replying,
In fact I'm modeling a porous media and through it a gas is circulating.The porous media is moving slowly(the gas flowing in cross-flow) that's why I have to take into account the advection term in the media temp equation,there is also a convective transfer between the media and the gas
When I implement the temperature equation of the media without source it's ok but when I couple it with the gas temperature it crashes.
boundaries are
for T:fixedGradient at the inlet,fixedValue at the outlet
for Tg:zerogradient at the outlet,fixedValue at the inlet
Information:the inlet is the inlet of the gas flow!
Thanks!

August 7, 2009, 03:18	help with advection-diffusion equation	#1
sambatra New Member andrianomena Join Date: Mar 2009 Location: madagascar Posts: 23 Rep Power: 17	Hi there, I'm solving an advection-diffusion equation(temperature equation) but it always crashes!!! Is it possible to solve an advection-diffusion equation?How? Can somebody out there help me please? Best Regards.

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August 7, 2009, 11:15		#2
titio Senior Member Antonio Martins Join Date: Mar 2009 Location: Porto, Porto, Portugal Posts: 112 Rep Power: 17	Hi, What are the boundary conditions, methods used, and other relevant information. Yiu have to give more information, otherwise I will not be able to help you. Regards, Titio

August 8, 2009, 06:18		#3
sandy Senior Member Sandy Lee Join Date: Mar 2009 Posts: 213 Rep Power: 18	Hi Titio, could you help me too? I want to simulate the true pressures in the domain but not some relative pressure values. What boundary conditions I should give. I gave a fixValue in inlet and a zerogradient in outlet, but the results are wrong. By the way, my problem is turbulence flows. Thanks a lot.

August 11, 2009, 05:54		#4
sambatra New Member andrianomena Join Date: Mar 2009 Location: madagascar Posts: 23 Rep Power: 17	Hi Sorry for the delay in replying, In fact I'm modeling a porous media and through it a gas is circulating.The porous media is moving slowly(the gas flowing in cross-flow) that's why I have to take into account the advection term in the media temp equation,there is also a convective transfer between the media and the gas When I implement the temperature equation of the media without source it's ok but when I couple it with the gas temperature it crashes. boundaries are for T:fixedGradient at the inlet,fixedValue at the outlet for Tg:zerogradient at the outlet,fixedValue at the inlet Information:the inlet is the inlet of the gas flow! Thanks!