Learning Forum

[azylee]

I am completely new to Fluent. I'm trying to simulate a water tap running downwards onto a ping pong ball which is lying on a flat surface.

[peteroznewman]

nSince you are completely new to Fluent, I recommend you start with some simpler Fluent models and build up to this model once you have experienced success with a few simpler models. There are many courses in Fluent on this site that will give you a good foundation.n

[azylee]

Thank you for the tip.nSo far, I have done 2D and 3D jet impingement on a stationary object. Which simpler Fluent models in particular do you recommend?n

[Rob]

The problem with the moving ball is that you're changing the mesh topology: read up on wall contact in the moving mesh chapter of the Fluent documentation. n

[azylee]

nThanks. Is this the document you're referring to?: https://www.afs.enea.it/project/neptunius/docs/fluent/html/ug/node250.htmnSo, the base must be defined as a stationary wall, and the face of the ball must be defined as a moving wall? However, I can't define its velocity or rotational speed as the purpose of the simulation is to determine these variables.nI defined the ball face as moving, relative to adjacent cell zone, translational, with speed 0 in direction [1,1,1], but the negative cell volume error occurred.n

[Rob]

No, if you click on Help in the solver you'll get the current version documentation and not a random third party copy. You'll need to use the 6DOF solver, so assign mass, cog, centre of inertia ect and then let the solver work out where it's going. nRe the negative cell volume, it's been asked many times on here before. n