[Sarah.g]

Hello everyone!

I am new to Fluent and I need help. I would appreciate comments or feedback.
I am simulating plasma in solid rocket plume to find electron number density. To get electron number density I need to make some approximations because the physical behind solid propellant motor flows is complicated. These approximations are:
• The actual exhaust flow field of solid propellant rocket motors contains alumina particles. Assuming that the gas and solid phases have achieved equilibrium, thus employing the mean properties of combustion gas and alumina particles.
• The molecular weight of the flow is almost the same as that of air, assuming that the fluid properties outside the plume are the same as those within the plume, which allows us to adopt the one-fluid approximation. Thus, the frozen flow plasma density is proportional to the flow density.
My questions are;
1) I used air as a material in the combustion w.r.t. one fluid approximation. Is it correct to use only air as a fluid? Can you explain what is one fluid approximation in Fluent?
2) In paper that I followed the propellant is HTPB+ Aluminum perchlorate + Aluminum. As I understood in the paper, they use one fluid in the combustion. Do you have any suggestion which material I can use as a combustion gas?
Set-up
The conditions: Chamber Pressure is 10 MPa (nozzle pressure inlet)
For analyze at sea level condition my fluent set up is
• The material is air
• Solver type: Density-Based. Time: Steady. 2D Space: Axisymmetric.
• For Models: inviscid
• For boundary Conditions;
a. Pressure_inlet(nozzle): Gauge Total Pressure: 10 MPa
Combustion temperature: 3600K
b. Pressure_Outlet: sea level condition
• Solution Methods;
a. Formulation: implicit
b. Flux Type: Reo-FDS
c. Gradient: Least Squares Cell Based.

I attached my mesh.

The paper that I followed is: ‘’ Computational fluid dynamics and frequency-dependent finite difference time-domain method coupling for the interaction between microwaves and plasma in rocket plumes’’ K. Kinefuchi, I. Funaki, T. Shimada, and T. Abe

Any feedback would be appreciated.

Thanks,

[renanalmeids]

Hey sara, did you have any advance?