[caiorsf]

In the blue injector, oxidizer with density rho1, surface tension s1 and dynamic viscosity mu1 flows , while in the red, fuel with density rho2, surface tension s2 and viscosity mu2 flows. A region for mixing these two substances exists as shown in the figure https://ibb.co/Gt0HMXX https://ibb.co/t3BSKC6. Given that the oxidizer (nitrous oxide) and fuel (ethanol) are miscible, I would like to know the mean value of the transport properties (density rho3, surface tension s3 and viscosity mu3) of mixture in that region.

First I tried to simulate only the flow in the oxidizer injector, in other words, no mixture. I chose the multi-phase and VOF models* , because besides the oxidizer, air is present too and appears as an air core in this kind of problem (swirl flow). The results of this simulation seemed reasonable to me. So the next step would be the simulation of the real problem.

I applied the same logic to the problem with three substances (air,oxidizer and fuel), but the solution didn't converge. Now we have three phases and FLUENT asks as one of the inputs the surface tension of oxidizer/fuel which I don't know (the other two are surface tension of the oxidizer/air interface and fuel/air), so I inserted the value zero.

About the theoretical background, I reviewing/studying the Cengel's fluid mechanics book, but it does not contain a description of multi-phase flows, so if you guys have some recommendations of books about this and the models used in the swirl flow,I'll appreciate it.

[allenjosef]

Hi, we are dealing with a similar kinda problem(bipropellant coaxial swirl injector). Do you mind sharing the steps to solve this. We are trying to simulate with liq Oxygen and kerosene and trying to find the breakup length and SMD.

[allenjosef]

Hi Caio, thanks for the reply.
email: 17me017alle@ug.cusat.ac.in

[allenjosef]

This probably requires a VOF to DPM transition model.