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Laminar Flow

Posted Apr 1, 2017, 6:52 a.m. EDT Fluid & Heat 1 Reply

Adil Mustafa
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Hi,

I'm simulating a micro channel using Laminar flow Physics. My model works perfectly when i give flow rate at the input and chose "0" Pa at the output. The solution doesn't converge when i chose flow rate at the output as well. I'm new to the fluid flow simulations and i'm not sure if i was able to make my self clear.

Regards
Adil
1 Reply Last Post Apr 1, 2017, 12:25 p.m. EDT
Mohammad Amin Kazemi
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Posted: 8 years ago Apr 1, 2017, 12:25 p.m. EDT

Hi,

I'm simulating a micro channel using Laminar flow Physics. My model works perfectly when i give flow rate at the input and chose "0" Pa at the output. The solution doesn't converge when i chose flow rate at the output as well. I'm new to the fluid flow simulations and i'm not sure if i was able to make my self clear.

Regards
Adil


Adil,
I'm not sure about my answers. However, there are two issues with your new boundary condition:

1) When you impose a flow rate at a boundary, Comsol applies a uniform velocity at that boundary, which physically does not happen at the channel's outlet.

2) Imposing a uniform velocity distribution at both ends means that there is no pressure difference between the inlet and outlet. So Comsol can not find a solution for this pressure-driven flow.

Amin,
[QUOTE] Hi, I'm simulating a micro channel using Laminar flow Physics. My model works perfectly when i give flow rate at the input and chose "0" Pa at the output. The solution doesn't converge when i chose flow rate at the output as well. I'm new to the fluid flow simulations and i'm not sure if i was able to make my self clear. Regards Adil [/QUOTE] Adil, I'm not sure about my answers. However, there are two issues with your new boundary condition: 1) When you impose a flow rate at a boundary, Comsol applies a uniform velocity at that boundary, which physically does not happen at the channel's outlet. 2) Imposing a uniform velocity distribution at both ends means that there is no pressure difference between the inlet and outlet. So Comsol can not find a solution for this pressure-driven flow. Amin,

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