Learning Forum

[Mohammad Fikri]

Hi, i have tried to do 3D simulation of flow boiling in fin array like this picture, but because of it took lots of times, i want to do 2D simulation instead. the model is like the other picture, the problem is i couldn't set the heat flux boundary condition in the 2D model, does anybody know how to set the heatfux while maintaining the fin array? Thank you

 

[Rob]

If the heat flux is from the plate you'll not beable to do that in 2d, it's a 3d effect. You could estimate the flux to the individual pins and compare the two approaches. 

[Mohammad Fikri]

Thank you for your respons, So there is no other approach to do 2D except using the heatflux from the pins and 3D approach, i have done the pins approach, but because of the arrays are not dense enough, the flow boiling only happening near the pin, while in 3D models, the boiling occured more uniform across the plate.

[Rob]

Which makes sense as the plate will have a longer contact time with the fluid. There's no reason why you can't model a section like your 2d image in 3d to conserve mesh. However I'd tend to model 3-5 repeats to ensure any asymmetry in the flow can develop: there are gas turbine combustor papers out where 5 burners (annular combustor) were modelled to ensure the central burner flow was not effected by the side boundaries. I don't have the reference, but as it's public I can share the modelling suggestion (we're restricted in what we can share on here).