[Benzaa]

Hi,

I am working on modelling a two phase flow; one is solid and the other is a gas.

I have a doubt regarding the continuity equation for the gas. I hope you can help me to get around this.

In my model, solid and gas are reacting, while solid is falling due to gravity. The mass generated by the gas-solid reactions is transfered to the gas.

The continuity equation for a gas is: D(rho)/Dt = 0.

But, I am wondering, if for my problem, I have to add another term that represents the total mass that is added to the gas flow. I am thinking that it should look something like this:

D(rho)/Dt = R

Where R is the sum of all the mass generated by the gas-solid reaction.

By using this equation, the SIMPLE algorithm changes a little bit.

Is it ok to do this, or, should I just consider the first equation.

Thanks is advance for your help.

[CFDtoy]

Hi Benzaa,
If the mass of gas is increasing or decreasing - or solid mass is dec or increasing...you would require a source term on the volume fraction eqn. If you are simply solving a eulerian gas phase eqn and a lagrangian tracker
for the solid phase, no rhs term exist.

CFDtoy

Originally Posted by Benzaa

Hi,

I am working on modelling a two phase flow; one is solid and the other is a gas.

I have a doubt regarding the continuity equation for the gas. I hope you can help me to get around this.

In my model, solid and gas are reacting, while solid is falling due to gravity. The mass generated by the gas-solid reactions is transfered to the gas.

The continuity equation for a gas is: D(rho)/Dt = 0.

But, I am wondering, if for my problem, I have to add another term that represents the total mass that is added to the gas flow. I am thinking that it should look something like this:

D(rho)/Dt = R

Where R is the sum of all the mass generated by the gas-solid reaction.

By using this equation, the SIMPLE algorithm changes a little bit.

Is it ok to do this, or, should I just consider the first equation.

Thanks is advance for your help.