Advice on vertical axis turbine modelling
 

Dear all

I have just started my PhD and need to model a vertical axis turbine. I am new to cfd and would like your advice.

I need to model the turbine flaps opening and closing, they open/close depending on the fluid flow, and are not motor driven. Their movement is restricted to 180 degrees.

My problem is a bit like trying to model the wind blowing a door open, and if the wind was coming from the other direction, it would blow the door shut. my question is how would you model this? is it a fsi problem? or do I have to predict the position of the flaps (not desirable)? I have been told that I would need to write a udf to calculate the movement based on the pressure difference either side of the flap- is this a recommended way of solving this? or in flow 3d can the general moving object handle this?

I have been advised that either fluent or cfx have this capability, but it looks like flow-3d could also be up to the job- which software do you think is more appropriate?

Any ideas/suggestions are extremely helpful as I am trying to gather as much infomation as possible at the moment.

Many thanks in advance

James

James,

If the flap is defined as a coupled-motion GMO component, its dynamics will be computed in FLOW-3D as a function of the pressure and viscous forces along the surface of the flap.

It is a straight-forward task if the axis of rotation is fixed. You can also fix the angular movement, on both sides of the range, to limit it to 180 degrees.

Thanks MuxaB,

the flaps will need to also move around a central axis- the problem is similar to a typical lift type turbine- like a darrieus model, but the flaps/or foils are free to move as already described. being able to restrict their movement to 180 degrees is excellent. with this additional rotation in mind do you still think that i would be able to model it?

Do you/ does anyone know how easy it is to obtain a trail version of the software, im in contact with them at the moment but was wondering what the chances are of getting it, im keen to start learning it!!

Many thanks for all your help!!

James

i don't see why you'd have problems getting a trial version.

I can't me completely sure without seeing the geometry of the device, but sounds it is quite doable. You should ask FSI when requesting a trial license, so you don't waste your time learning it. Send FSI a schematic of the device to get a more reliable opinion.

Looks like you got into a wrong forum by mistake...