Tracing the boundary layer development over a flat surface in natural convection

Arvin · October 10, 2013, 21:43

I am working on natural convection over a flat plate. I created the geometry in gambit with face mesh with around 10,000,00 nodes. I am analysing 2d steady state but even after 10000 iterations, I am not able to get plumes moving up from bottom surface.Working fluid is water.Flux supplied to bottom plate( copper) is 500. Side walls are glass with temperature of 300K.Please do help me with your suggestions. Thanks!!

Bionico · October 11, 2013, 02:19

Hi Arvin,
check if you have turned ON gravity and if you have set up the density law (as a function of Temperature) in Materials Menu.

Kind Regards

Arvin · October 11, 2013, 09:39

Hi Bionico. I have set up density as Boussinseq approximation. Gravity is turned ON. I didn't attach a boundary layer mesh. Does it affect this problem?. The geometry is rectangle.

Bionico · October 11, 2013, 11:27

Yes, it may affect your simulation: you should have y+=1 in the first layer of boundary layer.

Kind regards

Arvin · October 12, 2013, 00:39

I have started the simulation using polynomial for density of water. The expression is 1000-0.02T. Currently I am using pressure based solver. Is it ok to continue the simulation?

Bionico · October 14, 2013, 02:18

I don't know if polynomial law is suitable for water (I assume that you already studied some books); the solver is ok. Go ahead!

Regards

October 10, 2013, 21:43	Tracing the boundary layer development over a flat surface in natural convection	#1
Arvin New Member Arvindh Join Date: Oct 2013 Posts: 19 Rep Power: 12	I am working on natural convection over a flat plate. I created the geometry in gambit with face mesh with around 10,000,00 nodes. I am analysing 2d steady state but even after 10000 iterations, I am not able to get plumes moving up from bottom surface.Working fluid is water.Flux supplied to bottom plate( copper) is 500. Side walls are glass with temperature of 300K.Please do help me with your suggestions. Thanks!!

October 11, 2013, 02:19		#2
Bionico Senior Member Flavio Join Date: Sep 2011 Location: Brescia, Italy Posts: 181 Rep Power: 15	Hi Arvin, check if you have turned ON gravity and if you have set up the density law (as a function of Temperature) in Materials Menu. Kind Regards __________________ Bionico

October 11, 2013, 11:27		#4
Bionico Senior Member Flavio Join Date: Sep 2011 Location: Brescia, Italy Posts: 181 Rep Power: 15	Yes, it may affect your simulation: you should have y+=1 in the first layer of boundary layer. Kind regards __________________ Bionico

October 14, 2013, 02:18		#6
Bionico Senior Member Flavio Join Date: Sep 2011 Location: Brescia, Italy Posts: 181 Rep Power: 15	I don't know if polynomial law is suitable for water (I assume that you already studied some books); the solver is ok. Go ahead! Regards __________________ Bionico

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October 11, 2013, 09:39		#3
Arvin New Member Arvindh Join Date: Oct 2013 Posts: 19 Rep Power: 12	Hi Bionico. I have set up density as Boussinseq approximation. Gravity is turned ON. I didn't attach a boundary layer mesh. Does it affect this problem?. The geometry is rectangle.

October 12, 2013, 00:39		#5
Arvin New Member Arvindh Join Date: Oct 2013 Posts: 19 Rep Power: 12	I have started the simulation using polynomial for density of water. The expression is 1000-0.02T. Currently I am using pressure based solver. Is it ok to continue the simulation?