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-   -   Particle Impact Velocity (http://www.cfd-online.com/Forums/cfx/79694-particle-impact-velocity.html)

Batis August 31, 2010 12:19

Particle Impact Velocity
 
Hi,

does anyone know, how exactly the Particle Impact Velocity is evaluated? I would like to know, if the Restitution Coefficient has any influence on this evaluation.

Thanks,
Batis

ghorrocks August 31, 2010 18:22

? It is simply the velocity at which the particle strikes the wall. Restitution coeff has no affect on it as it only affects the velocity at which the particle leaves the wall.

Batis August 31, 2010 19:06

Thanks for reply.

So I was thinking, but I've made some particle erosion parameter study and my results show that Erosion Rate increases with decrease of Perpendicullar Restitution Coeff. I was wondering what was the reason and its influence on impact velocity came to my mind.

Thanks,
Batis

ghorrocks September 1, 2010 20:00

You would have to look up the erosion model in the documentation and then chase up the references for the erosion model.

Batis September 1, 2010 23:21

I know the formulation of erosion model very well, and I've also read several references. The only variables affecting the erosion ratio (in Finnie erosion model) are: impact velocity and impact angle.

Thanks,
Batis

ghorrocks September 2, 2010 18:44

That answers your question, doesn't it?

Keep in mind that the particle might strike the surface several times, and the restitution coefficient will affect these bounces.

Batis September 4, 2010 08:23

Yes, probably this is the reason. But what is interesting, the distribution of Erosion Rate Density on walls surface is almost the same for all cases, only the value differs for different Rest. Coeff. values.

Thanks,
Batis


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