Governing equation

Priyank Mehta · February 15, 2018, 23:37

Hello
I am facing some problem regarding governing equation used by the fluent.

Governing equation for the mixture model.

1. In the equation, I think for Incompressible part there should be Kintectic energy part. Means For Incompressible E = h + v2/2

2. From where I can get the derivation of this equation.

Hoping for your reply

LuckyTran · February 16, 2018, 11:51

For the incompressible case, the kinetic energy and potential energies are exactly balanced by the mechanical work due to viscous forces. You can find this in Frank White's Viscous Fluid Flow. Or you can compare eq(7) to eq(10) in Energy Equation in OpenFOAM. Then compare eq(14) to 23.4-7.

What has happened here is they have dropped the viscous dissipation term so it is lost how the bulk kinetic energy disappears.

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February 16, 2018, 11:51		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,675 Rep Power: 66	For the incompressible case, the kinetic energy and potential energies are exactly balanced by the mechanical work due to viscous forces. You can find this in Frank White's Viscous Fluid Flow. Or you can compare eq(7) to eq(10) in Energy Equation in OpenFOAM. Then compare eq(14) to 23.4-7. What has happened here is they have dropped the viscous dissipation term so it is lost how the bulk kinetic energy disappears.