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Fluid flow and heat transfer in heat exchanger

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Dear All,

I am solving a conduction- convection heat transfer problem with 2 dimensional in shell and tube heat exchanger.

Problem Description are as:
The size of inner radius of tube is 6mm. and
outer radius of shell size 12mm.
Now from the inner tube heat transfer fluid is flowing with velocity of 15m/s with constant temperature , (say 200°C).
Whereas, in the shell there is solid phase change material with melting temperature of 34°C.

I put all the thermophysical properties of phase change material as well as heat transfer fluid.

And run the simulation for 6h. but results are not obtained?

The following results i want to check: 1) how the heat transfer takes place from heat transfer fluid to phase change material ( i.e. conduction and convection)

2) At what time the convection will start?

3) I am using fluid thermal interaction module of non-isothermal flow. whether it is correct? or I have to used another module.

Please suggest me how to solve the above problem or give me some guidelines so that I can solve the problem.

Thanking you .

Sincerely,
Vinay Patel.

2 Replies Last Post 05.02.2014, 13:55 GMT-5
Patcharapit Promoppatum

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Posted: 1 decade ago 05.02.2014, 13:41 GMT-5
Hi,

I used to have similar problems. Since your velocity is very high. You might try to reduce to lower velocity and see if the model is converging. Moreover, you might use step function to ramp your flow at beginning so in this case you could avoid shock flow.
In order to check your model, you might also consider disable the properties of PCM at the beginning and use some other built in material to save the computation time.

Hope this help!
Joe
Hi, I used to have similar problems. Since your velocity is very high. You might try to reduce to lower velocity and see if the model is converging. Moreover, you might use step function to ramp your flow at beginning so in this case you could avoid shock flow. In order to check your model, you might also consider disable the properties of PCM at the beginning and use some other built in material to save the computation time. Hope this help! Joe

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Posted: 1 decade ago 05.02.2014, 13:55 GMT-5
Dear Sir,

Thank you for your valuable suggestion.

I will put the lower value of flow velocity and use other material instead of PCM.

I will reply to you.

Thanking you,

Sincerely,

Vinay Patel
Dear Sir, Thank you for your valuable suggestion. I will put the lower value of flow velocity and use other material instead of PCM. I will reply to you. Thanking you, Sincerely, Vinay Patel

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