[mohcin]

hi everybody,

I am trying to design a 2d model of double pipe heat exchanger in gambit and analyse that model in FLUENT. The problems that I am facing now are:

1): How to solve a double pipe heat exchanger in Fluent?
2): How to assign the solid material (Phase change material) in the annulus of double pipe and hot water in the inner pipe?
3): Do I have to activate the heat exchanger option from fluent or the multiphase option? I am experiencing errors when I enable the hat exchanger option in Fluent?

Kindly help me.

Thanx

[sudha]

hi!

As i understand, the double pipe heat ex-changer has two fluids and one or two solids for the pipe material.

since, you wish to model in 2D, make the mesh and define the two fluid zones separately and also the solids (the inner pipe thickness is sufficient to model if you are neglecting the radiation losses to atmosphere & just mention the outer pipe to be a wall)

now in fluent, you can choose existing material or create a new material for the analysis and apply for each of the zones int he boundary conditions.


hope this helps you,

have a great time.

sudha

[mohcin]

Thank u for ur kind repy. I have done these things but its still not working and giving errors like Divergence detected in AMG solver: temperature?

[hittie]

sometimes its caused by the model you selected: are the 2 fluids of the same kind (compressibility, turbulence)?
i had also the same problem using Fluent with a heat exchanger. Fluent has difficulties to simulate laminar flows together with a turbulent flow for example.

[mohcin]

Hi all,
I 've been trying to create a 2-D model of double pipe heat exchanger and im not sure with the boundary conditions. I 've attached the picture of my model before applying applying the boundary conditions. Can anyone help me out with the boundary conditions ??

Inner pipe - Copper
inner fluid - Water
Outer pipe - copper
Outer fluid - Phase changing material ( The problem is with this material. Im not sure whether the boundary condition for this should be a wall or anything else)

Kindly help !!

Thank you
Regards,
Mohcin

[hittie]

i'll will suggest you to use the velocity conditions (instead of pressure conditions-->its more stable) and you need to specify the material properties.

The velocity conditions are applied at the inlet and at the outlet. You need also to activate the energy equation

[mohcin]

hi,
Thanx for reply. I have done these things I give velocity inlet and out flow for the inner pipe and I considered all other boundary conditions as copper (wall). Is it right or anything else to be considered/

Thanx

[hittie]

normally it looks good.

[mithun80]

Hi,

I was wondering if any of you ever did an ansys workbench simulation on compression springs. I was trying to simulate the spring compression, but the spring always interferes with both the contact plates during simulation. I know this could be done as I have seen the animation of the spring in youtube when it compresses. But I am just not able to figure it out. Any help is really appreciated.

Thank you
Mithun

[m7566]

sir how u make double pipe heat exchanger geometry in gambit. if u have any design tutorial for this geometry please send me please help me. i am using 1st time gambit so i am not constructed this geometry . please help me

[m7566]

sir please send me step by step procedure for making double pipe heat exchanger geometry

[m7566]

sir will u send me your jou file og gambitm plese sir help me
my mail id is m9713001413@gmail.com

[umararshad91]

Have you solved this problem? I need help

[m7566]

Originally Posted by umararshad91

Have you solved this problem? I need help

yes not cmpltly . i have solved this problem partially complte. because my under standing to ansys fluent in meshing part and solver part limited and i don't have time because of project dead line.

[m7566]

Originally Posted by m7566

yes not cmpltly . i have solved this problem partially complte. because my under standing to ansys fluent in meshing part and solver part limited and i don't have time because of project dead line.

i have spent 10 month on this problem, if i have guidance on that time may be i am able to publish a paper.

[umararshad91]

can you please share case n data file here? or some tutorial?

[m7566]

Originally Posted by umararshad91

can you please share case n data file here? or some tutorial?

no firstly tell me how long you reach to solve this problem.

[m7566]

Originally Posted by m7566

no firstly tell me how long you reach to solve this problem.

last time i was helping some one he do only copy paste for thesis

[umararshad91]

I need this in a job assignment only. I want to simulate thr boiling water flow in pipe on one pipe and subcooled water in other. But when I use RPI wall boiling model of fluent I get divergence always...

[umararshad91]

Originally Posted by m7566

last time i was helping some one he do only copy paste for thesis

I need this in a job assignment only. I want to simulate thr boiling water flow in pipe on one pipe and subcooled water in other. But when I use RPI wall boiling model of fluent I get divergence always..