[lirilisback]

i have made a model of air cooled two wheeler vehicle's engine block. Now i want to study the effect ofcooling with different FIN design over different air speed. Its conjugate heat transfer problem. The geometry is quite complex. I took half section. steps i followed are :
Geometry : import half section geometry >> Made fluid domain with enclosure command >> Named 'inlet' and 'outlet' for fluid domain and 'inside wall' for the cylinder block.
Mesh : Fine mesh
Fluent : energy equation ON, turbulent model k-epsilon (2-eq),
Boundary condition: insidewall temp-423 K, inlet fluid velocity-20m/s
solution initialization from inlet (everything else default)
Now my problem is : the energy equation residual is not converging. Its going up nearly 1e-2. Continuity equation is converging fastly.
Results : i'm getting nice velocity and pressure contour. But temperature contour is showing blue colour through entire geometry. I'have attached pics.
Please tell me the solution for the above problem.

[devesh.baghel]

Hi,

you should increase the size of boundary as it looks in picture.
Can you please share picture of mesh as well as temperature contour plot.


Regards

[lirilisback]

@devesh.baghel
Hello sir, Thanks for reply,
I changed few things and i got the result.
Geometry : I applied subtract boolean operation. I subtracted the engine body from fluid enclosure.
Fluent set up :
Double precision. Parallel with 2 process. (earlier it was series). Changed temp from 423 k to 600 k ,increased velocity from 20m/s to 40m/s.

But i've a question :

I took half section of the engine cylinder. Still it takes too much calculation time. For 1000 iterations it takes 10 hours. So what should i do to reduce calculation time. ?

[mahipal parmar]

hi..i am trying to solve double pipe heat exchanger using inserts in CFD.
i used- double precision,
energy eq-on
model-turbulent(2 eq,stnd wall fun)

solution method:-SIMPLe(PRESSURE-VELOCITY BASED)-second order
my energy residules are not converges during solution.so ans is not converged.

boundary conditions:-
hot inlet:-mass flow rate-1.3 kg/s,inlet temp-413 k
hot outlet-pressure based
cold inlet:-mass flowrate-1.3, temp-298 k
cold outlet:-pressure base
my problem is my energy residual is not converged and it increasing and it be e+08.while the convergence criteriya is e-06 ..
.any one can help me why this kind of problem is occured.

any one have solution?plz guide me.
thanks in advance.