Niagara Fluids – Diving into the guts of the CFD model and units, HELP!

Hi all!

I am very interested in learning more details about the physical CFD model that governs the Fluids plugin. Is there any post or publication about it?

I also keep asking the community for more details about the units used in Niagara: lengths, speeds, accelerations, rotations, forces etc. There is very little (or none) information about it and for me it is important.

Although I have been able to deduce some of the magnitudes, I still need to know those of many parameters, especially in Fluids (pressure, confined vorticity, temperature, density, temperature and density attenuation, etc.). Any information on this will be truly appreciated!

My main interest is the development of Serious Games for training firefighters in wildfire scenarios, for which I need my models (especially fire, smoke and particles) to be physically based and visually reasonably realistic. I’m not looking for a complete CFD solution (for that I already have Fluent or FDS), just that the flames and smoke have a realistic volumetric appearance in UE scenarios. Which is why I fully discarded using sprites from the very beginning and now I am embracing Fluids with much excitement.

Although Niagara Fluids is a promising tool, I have not yet been able to interpret what the parameters mean in the real world. For example, after many trials, I have been able to deduce the relationship between the temperature parameter (I’ll call it ‘temp’) in Fluids and the actual temperature in ºC. I leave here the approximate equivalence table I have found for the black body color map, in case it is of any use to you:

But I still need to understand how Fluids works and what the rest of the parameters mean, in particular how the heat transfer is solved (at first it seems that only convection is used, but contact or radiation seems to be neglected or not calculated); or how the turbulence is solved (LES model or others?), and so on.

I would also like to know if Fluids supports loading external files as boundary conditions, in particular scalar fields (like temperature or pressure) and vector fields (like wind field). This would allow me to establish starting conditions for the simulations that would reflect real situations. For me it is especially important to show how the structure of the atmosphere (thermal gradient) affects the buoyancy of the flames and smoke, or how the wind (calculated in other CFD solutions) affects the advection of the simulation in Fluids.

Any information or publication about these subjects will be of great help.
Thank you very much to all.


PS.: Some of my preliminary experiments with Fluids in my YouTube channel: