screw pump
 

Does anyone know of a software tool that can simulate flow in a displacement pump (screw pump)

Re: screw pump
 

Hi,

when I was a student 6 years ago, I work on a project, where we tried to simulate a srew pump for pumping a liquid-gas mixture (the application was for off-shore oil pumping). We developed also a simulation program for the pump. Results were published in a phd-thesis by:

Stephan Etzold

Verlustanalyse von Schraubenspindelpumpen bei Mehrphasenfoederung

Forschr.-Ber. VDI Reihe 1 Nr. 221. Duessedorf: VDI-Verlag 1993.

I hope this is useful for you. For more information you may contact me directly.

Heinz

Re: screw pump
 

I guess most of the good CFD tools should be able to handle this problem with a certain degree of sophistication. The level of sophistication that you require (that is the level of physics to be modeled) really determines your choice.

CFD-ACE+ from CFD Research Corporation (http://www.cfdrc.com) offers excellent capabilities for modeling flow in screw pumps. You can include the full effect of cavitation when using CFD-ACE+.

To learn more about the capabilities of CFD-ACE+ and cavitation modeling through CFD-ACE+, please visit our website, http://www.cfdrc.com, and check out the details on the cavitation model in the "What's New" section. You are also welcome to contact me directly at rmm@cfdrc.com and we can discuss your needs in more detail.

Re: screw pump
 

Hi,

I agree CFDRC products are nice, but are you certain to be able to simulate a screw-pump using CFD-method for the whole pump?

The reason I ask, the screws are very complex in geometry, with moving chambers formed by the screws. Then ther will be pressure jumps in the system. Big differences in sice, as gaps between the screw and the housing are important to be treated as well correct. All not very easy to treat in a CFD Code I think. If you have a calculation like that running, please show me!

Ciao Heinz

Re: screw pump
 

You may want to take a look at STAR-CD. It supports a variety of transient motion capabilities including sliding interfaces, nodal movement, dynamic attachment/detachment and cell addition/removal. More information can be found on www.cd.co.uk. Good Luck!

Re: screw pump
 

It may be a complex problem. But there is nothing in it that can not be handled by CFD-ACE+. Yes solving for the whole pump means big grid and a lot of computations but... I don't know why you doubt CFD will be able to handle this problem.

Re: screw pump
 

(1). I think, if there is a code configured to run the flow through a screw pump, then we can say that such code is available. (2). If such code has been used in the field and has been validated with test data, then we can say that such code is reliable and has been validated. (3). If there is only a collection of libraries, then we can only say that there could be a potential to solve the flow through a screw pump. (4). We really have to raise our standard such that it matches the standard of professionals such as a dentist, a doctor, or a nurse. Would you go to a family doctor and ask him to perform brain surgery on a patient? (5) If we wish to survive, then everyone must help maintaining the standard. Otherwise, it is nothing but a joke. ( I have just corrected an error in a code which has been there for over five years. Each time I run the code, it always print a total pressure at the inlet which is higher than the value I specified. There were two short lines of the code which change the results and input. You don't ask why, it was put there by someone else. ) (6). I think, the geometry of a screw pump is highly complex and 3-D. The moving gaps should be included in the calculation because of the high pressure environment. (7). There is a 2-D pump of positive-displacement with moving boundary. It is called scroll compressor. It is widely used in house-hold and automobile air conditioning compressor units. The fluid is drawn from the outside and gradually squeezed to the center of the scroll, and discharged there. In this case the geometry is 2-D. One also has to worry about the seal and leaks. The complexity of this types of problem is that, the boundary shape is changing all the time and at the same time one has to consider the leak problem. In the screw pump case, the moving boundary is 3-D. And one also has to consider the gaps and leaks. So, I would say, this is a highly complex problem.

CAD Import
 

I have a CAD model for micro screw pump and I imported it to Phoenics
but I have a problem to rotate the pump in the flow and to lineament the pump on the center of the Phoenics
if any one can help me please reply