Hi SimScale, I am working on my final monograph and it is about an axial water pump simulation. The problem is that my experimental result delivers a Head of 0,26 [m] while the SimScale result shows 29 [m] for the Head (like x10 above). Please, what is wrong with my simulation? The project link is…

BINGO !! :smile: :crazy_face: While I was making the parabolic csv data to ramp rpm up from 0, I was just looking at the mesh and coordinate arrows and BINGO. SO, I think the pump was rotating backwards… I believe the direction of rotation in rotating zones is with respect to the faces you select…

Perhaps I should say ‘center of rotation’ ALONG 0 of one of axes. Example: base of your MRF cylinder can be at Z 0 m, top of cylinder at Z 2.0 m (if rotation axe is ‘Z’). You can, but do not need to align ‘geometric center’ of MRF zone to 0,0,0. For ‘load’, try to go with ‘parabolic’ curve, which…

Progress Report - No much luck yet I created a new project and created my own mesh and simulations from scratch after I modified and imported the original ‘axial’ geometry file in RHINO. Geometry changes made in Rhino (named ‘axial-DaleFan1p466m-new0’): Two of the rotor blades had many naked edg…

Two things, @DaleKramer : You have two sources of ‘inertial load’ into your pump (I did not know it before going to the project, now). You did apply ‘pacing load’ on your inlet but you started your turbine at full speed. It is an obvious mismatch, you can fix. By chance your setup keeps now for 43…

[image] Retsam: May I bring your attention also to ‘Forces and moments’ you defined which are centered on Y axe, ‘-0.55669’, for all blades, that seems incorrect, as you rotate on X axe. Please correct me if I am wrong, but my understanding is that the point which you choose for ‘Center of Ro…

I see your point, but perhaps somebody would need to jump in that "Forces and moments’ setup on multiple, not connected bodies. I also make possibly invalid assumption about ‘geometric center’ of that assembly of blades. One more point is that I would add separate ‘sensors’ to inlet and outlet in o…

[image] Retsam: One more point is that I would add separate ‘sensors’ to inlet and outlet in order to be able to observe the discrepancies… Since the head is determined by the difference in pressure between inlet and outlet, and the outlet has a boundary condition of 0 Pa, we only need an are…

That I understand: I said ‘sensors’ instead of ‘probes’ in space before and after rotating zones. This would give idea of fluid movements in that idea.

Good news: @jousefm also confirmed, some time ago, the right hand rule when asked, which I quickly invalidated with my MRF zones experiments. And forgotten. As of today, left hand rule is used by software. But now, if it is fixed, all previous simulation will fail, if restarted.

Hi @DaleKramer , Firstly, thanks for the help!! Please correct me if I am wrong, but following the ‘right hand rule’ the green arrow showing below is the vector direction that you defined in your last run, right? But the real rotor direction is represented by the red arrow below… What can you say t…

SimScale CAE Forum

Axial Pump

Project Support

DaleKramer March 8, 2019, 3:27pm 36

If the rotor rotates in the red direction, it will push water towards the inlet, would it not?

1 Like