emitting combustion properties

[calibrix]

Hi,

I'm learning the workflow for bifrost combustion and I've found something that doesn't seem to work as expected. When emitting voxel properties during an active simulation, the fuel emission appears delayed by one frame. For example, if I want to inject voxel_fuel_methane values into my simulation at frame 3, it appears that those values don't actually appear until frame 4 and in-fact don't appear to react to temperature until frame 5. Perhaps I'm misunderstanding how the combustion model in bifrost works, but it appears if I want my explosions to happen at specific frames I have to account for a delay in when the reactants are actually accounted for in the simulation. I don't see this behavior when I'm injecting voxel_fog_density or voxel_temperature. If the source_air node has an arbitrary start frame fog_density and temperature properties are injected at those start frames. Substeps don't appear to have any effect on this phenomena. I have attached a scene file for reference.

Thanks in advance for you assistance.

[calibrix]

Hey Michael,

Thanks for the update. I've come across another issue that I can't quite solve. Let me know if I should separate this into a different thread as it's not exactly combustion related, but more related to emission of aero properties. When I'm emitting properties into the aero solver, it appears the properties lag behind the emission geo by a whole frame. This only happens when I'm not emitting on frame 1. Please see the example file.

 

[michael_nielsen]

Hi Chris,

Thanks for the report on delayed aero emission. I wasn't able to run the scene file due to missing compounds, but we have fixed the issue you previously reported: fuel emission delayed by one frame and combustion ignition also delayed by one frame. I suspect it is the same issue, but of course to be sure, feel free to send us the missing compounds from your scene file as well.

Cheers,

Michael