[hamedc]

Hi

I would like to conduct a simulation (diesel engine) with EGR (external EGR).
How to calculate mass fraction for this situation?
I took a look at SI8 premixed SAGE example case. it considers EGR as a residual gas (internal EGR) but i would like to have EGR as addition.
My next question regrading "How to calculate" when we have two mixture with different temperatures (for example air at 40C and EGR 90C)
What will happen if temperatures change?

[alireza.mashayekh]

Hi;

Typically, with EGR cases, you should know the percentage of the EGR you have. Since you have external EGR, you can set up your case 3 different ways:

1. Add the full loop of your EGR to your simulation. (very expensive)
2. Add a small piece of pipe in your geometry where your EGR loop connects to the air intake manifold. You'll then have 2 inflow boundary conditions; one for air, and one for your EGR. This way you can set different temperatures for EGR species and the air.
3. Add the exhaust products to the intake air manually (premix the two and set a temperature for the mixture), and set the new species mass fraction as your inflow boundary condition.

To do the calculations, you can use our 'Combustion products' calculator, which you can access in 'Regions and initialization' tab in Studio.

Best,

[sanket31594]

hello,

When I insert the mass fraction of CO2(for EGR) equivalence ratio changes. Solution for this?

Also where is combustion products calculator?

[MFGT]

Originally Posted by sanket31594

Also where is combustion products calculator?

In one of the latest releases of Studio.