[toolpost]

I am trying to simulate non-equilibrium condensation of steam in nozzles using Fluent with a custom wet steam model(using UDS and UDMs). Its a two equation model, the same one which is already available with Wet-steam model of Fluent. The equations can be found in this article.

https://www.sciencedirect.com/scienc...59431117302983

So what I am doing is, solving two additional UDS equations along with NS equations with source terms modified for accounting the effects of condensation. The parameters are calculated using a DEFINE_ADJUST macro and saved in UDMs, while source terms are applied using DEFINE_SOURCE macros. I am using density based, unsteady, 2D, AUSM solver. I already finished making the UDF and setting up the case, but couldn't make things work in the way expected. The UDF is compiling and running at properly at the beginning, but not giving realistic/satisfactory results. Also, I couldnt really understand the idea of implementing the evaporation process.

What I am seeking is, anybody here have experience with non-equilibrium condensation modeling? I can understand that, apart from writing up all equations and doing calculations, there have to be some tweaks/constraints setup to avoid divergence and problems during the course of solution.

Could someone have some suggestions/advises/ideas on the procedure I should follow to make things work? If somebody is interested, I am ready to share the UDF here.

Thanks in advance,

[lmahumada]

Originally Posted by toolpost

I am trying to simulate non-equilibrium condensation of steam in nozzles using Fluent with a custom wet steam model(using UDS and UDMs). Its a two equation model, the same one which is already available with Wet-steam model of Fluent. The equations can be found in this article.

https://www.sciencedirect.com/scienc...59431117302983

So what I am doing is, solving two additional UDS equations along with NS equations with source terms modified for accounting the effects of condensation. The parameters are calculated using a DEFINE_ADJUST macro and saved in UDMs, while source terms are applied using DEFINE_SOURCE macros. I am using density based, unsteady, 2D, AUSM solver. I already finished making the UDF and setting up the case, but couldn't make things work in the way expected. The UDF is compiling and running at properly at the beginning, but not giving realistic/satisfactory results. Also, I couldnt really understand the idea of implementing the evaporation process.

What I am seeking is, anybody here have experience with non-equilibrium condensation modeling? I can understand that, apart from writing up all equations and doing calculations, there have to be some tweaks/constraints setup to avoid divergence and problems during the course of solution.

Could someone have some suggestions/advises/ideas on the procedure I should follow to make things work? If somebody is interested, I am ready to share the UDF here.

Thanks in advance,

Hi toolpost. I'm new in fluent and I try setting up a similar case to the one you mention in a vortex tube. could you share the udf files that you used in your model? . i saw your post on ansys forum too.

my mail: Luz.ahumada14@gmail.com

thanks a lot!!

[weijiaLei]

Hi toolpost. Could you share the udf files that you used in your model? .

my mail: 1253226575@qq.com

thanks a lot!!