[nareshzeeda1994]

I'm doing my thesis on radiator through porous method.
I have calculated the viscous and inertial resistance.

But there is space for entering porosity.
Should I enter the calculated porosity value or should I leave it as 1 ?
Help me.

Thanks in advance

[Kushal Puri]

Originally Posted by nareshzeeda1994

I'm doing my thesis on radiator through porous method.
I have calculated the viscous and inertial resistance.

But there is space for entering porosity.
Should I enter the calculated porosity value or should I leave it as 1 ?
Help me.

Thanks in advance

If you are doing just flow analysis then no need to apply the porosity value, but if you are doing heat transfer then you have to give the value of porosity as well as you have to define the material also there.

[nareshzeeda1994]

Originally Posted by Kushal Puri

If you are doing just flow analysis then no need to apply the porosity value, but if you are doing heat transfer then you have to give the value of porosity as well as you have to define the material also there.

Thanks for your reply.
I'm doing heat transfer analysis on radiator.
The calculated value of porosity is 0.5
So should I give this value as porosity ?

[Kushal Puri]

Originally Posted by nareshzeeda1994

Thanks for your reply.
I'm doing heat transfer analysis on radiator.
The calculated value of porosity is 0.5
So should I give this value as porosity ?

Yes, you have to define porosity value of 0.5 and in the same window you have to apply the material also for heat transfer

[nareshzeeda1994]

Originally Posted by Kushal Puri

Yes, you have to define porosity value of 0.5 and in the same window you have to apply the material also for heat transfer

Actually I have a problem here. After giving all the inputs, I still dont see any difference in results.

Coolant in Temp is 363 K
Required coolant out temp is 353 K
But I'm getting 361.8 K

There is only 1 K drop in the radiator tube.

All the inout BC are correct.

Do you have any reason for this ??

[Kushal Puri]

Originally Posted by nareshzeeda1994

Actually I have a problem here. After giving all the inputs, I still dont see any difference in results.

Coolant in Temp is 363 K
Required coolant out temp is 353 K
But I'm getting 361.8 K

There is only 1 K drop in the radiator tube.

All the inout BC are correct.

Do you have any reason for this ??

What are the boundary conditions you are applying on the walls (like adiabatic or fixed ). Because heat has to transfer from there also.

[nareshzeeda1994]

Originally Posted by Kushal Puri

What are the boundary conditions you are applying on the walls (like adiabatic or fixed ). Because heat has to transfer from there also.

Thank You for your concern. I have solved the problem that was stated.

I have another doubt. Do you know the exact procedure to find out the inertial and viscous resistance ? I know the formula for inertial and viscous resistance.

Rv = [(150 (1-porosity)^2) / (sphericity^2 . Dhyraulic Dia^2 . porosity^3)]
Ri = [(3.5 (1-porosity)) / (sphericity . Dhyraulic Dia . porosity^3)]


How to calculate the sphericity value and what will be the value if it is rectangle and my dimensions are 2.83*0.08*49 mm

Thanks in advance.

[Kushal Puri]

Originally Posted by nareshzeeda1994

Thank You for your concern. I have solved the problem that was stated.

I have another doubt. Do you know the exact procedure to find out the inertial and viscous resistance ? I know the formula for inertial and viscous resistance.

Rv = [(150 (1-porosity)^2) / (sphericity^2 . Dhyraulic Dia^2 . porosity^3)]
Ri = [(3.5 (1-porosity)) / (sphericity . Dhyraulic Dia . porosity^3)]


How to calculate the sphericity value and what will be the value if it is rectangle and my dimensions are 2.83*0.08*49 mm

Thanks in advance.

I am not sure about this, but you can you use darcy law to calculate the inertial and viscous values. If you have the velocity vs pressure loss data.

[nareshzeeda1994]

Originally Posted by Kushal Puri

I am not sure about this, but you can you use darcy law to calculate the inertial and viscous values. If you have the velocity vs pressure loss data.

Hi Mr.Puri,

I'm simulating the entire cooling system ( radiator, CAC, Condenser ).

I simulated and have the results of each individual part.

Now I need to simulate it together by giving a single air velocity.

I thought to do it with Macro model method due to computational resources.

I even tried each part individually in Ungrouped Macro Model and got the results correctly.

Now I need to run it together. But I dont know how to do it? Should I use grouped or ungrouped macro model and how to do it ?

Please help in simulating it.

Thanks in advance.