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tim_shute February 2, 2012 01:30

Possibile to facilitate similar turbomachinery simulations by FloEFD
Repeated CFD simulation of a certain turbomachinery products (like vacuum cleaner, hair/hand dryer, blower/air mover and pump etc) with same components but different rotating part is inevetible, tedious and time consuming during selecting an appropriate rotating part. I would like to knwo if FloEFD's tools--user-defined fan and transfer result into a new simulation could relieve the working load and save time? My crazy thought include two points:

1. User-defined fan: replace rotating part with fully-enveloped sub-fluid domain (disable solid component) and add fan BCs into this sub-fluid domain. In this way, engineers have to initiate only one meshing process and use the meshing result (assum it is a good meshing) for further repeatition. Sounds nice. Here comes to the question, how to user-define a fan or input the P-Q curve? I tried to isolate a fan from the system but it seems the flow resistance/impendence is also needed.

2. Transfer result into a new simulation: isolate a fan from the system and do the external analysis and then transfer the result into a new simulation whose rotating part is replaced with fully-enveloped sub-fluid domain (disable solid component) as a BC and add other BCs into this model. Somehow, I feel kind of weird but I cant tell why. Actually, I dont think this mehtod can save time but it is a good way to resolve a large model under poor PC configuration.

Please give me slacker any comments on feasibility of this method, or advice/discussion on how to user-define a fan(P-Q curve)? Any is welcomed. Many THX in advance. :D

Boris_M February 6, 2012 09:52

Hi Tim,
it is generally possible to use a fan curve but you would need the P-Q curve either from measurements or datasheet. You can simply place a blow where the inlet and oulet is define the surface (right size) as inlet or outlet and select the defined fan from your database.
The fan can be entered in the engineering database under user defined in the fan group. Here you can define if radial or axial and give the fan a diagonal direktion by inner and outer hub etc.

The flow resistance is defined by the geometry in the rest of the flow therefore the calculation will iterate to the accoring pressure difference between inlet and outlet and use the corresponding point along the fan courve.


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