Learning Forum

[Zwernjayden]

I'm trying to model the regression of a hybrid rocket. This involves a shower style injector. I'm modeling it in 2D but I'm unsure how to model the injection as it's axisymetric, and selecting small sections in the inlet would basically just create channels

[Rob]

Maybe 2d axisymmetric?  

[Zwernjayden]

Ya that's how I set it up but I'm unsure how big the holes should then be as if you revolved it it would make concentric circles not holes.

[Rob]

Yes, which is why you can also model sectors. The problem with 2d/3d is balancing the inlet mass and velocity: you really need to get both right. 

[Zwernjayden]

If I take the total area of the holes, and create rings of equal thickness and equal spacing that total the area of the holes if the 2D surface were to be revolved, would that work? Basically in the 2d surface it would just look like multiple injections

[Rob]

Possibly, but would a slot produce the same level of mixing as the shower head arrangement? 

[Zwernjayden]

Probably not. My computer doesn't have the computing power to do it in 3D though

[Rob]

In which case write up the limitations for the student report and explain why you did it that way. Or ask for access to the campus system.