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No rating yet Subject: Re: Thermal analysis in electric motors Author: Mark Troscinski Date: 1999-09-02 13:06:00I see the Greek font did not fly in my last response! As a correction:
Ta = (rho*omega*r*b/mu)*(b/r)**0.5
Mark Troscinski
> -----Original Message----- > From: Mark Troscinski [SMTP:mark.troscinski@a...] > Sent: Thursday, September 02, 1999 1:03 PM > To: 'xansys@o...' > Subject: RE: [xansys] Thermal analysis in electric motors
> From: Mark Troscinski
> FLOTRAN can solve in rotating frames of reference! I thought everyone > knew that!
> If CFD is overkill for your application, you at least should compute > the > Taylor number for your system given by:
> Ta = (rwrb/m)*(b/r)**0.5, where "b" is the gap width and "r" is > the rotor's radius,
> to determine if viscous losses and convective effects are important. > I'd refer to page 525 of "Boundary-Layer Theory" by Schlichting for > info > on Taylor numbers and torque coefficients, etc. In the past, I have > used an old G.E.Data Book for Nusselt number correlations based on > Taylor numbers. If you need a copy, I can either e-mail you > separately > or perhaps FAX to you.
> Mark > _________________________ No Boundaries ________________________ > ANSYS, Inc. > Mark A. Troscinski > Multiphysics Product Manager > ANSYS Business Unit
> > -----Original Message----- > > From: Philippe Vidori [SMTP:vidori@t...] > > Sent: Thursday, September 02, 1999 11:51 AM > > To: xansys@o... > > Subject: [xansys] Thermal analysis in electric motors
> > From: Philippe Vidori
> > Dear xansys list,
> > This comes from a stress guy, therefore don't laugh at me !
> > I am presently working on the thermal analysis involving an electric > > motor whereas a heat source is applied to the windings, magnets > > and core. I have modelled a 3D sector including the air gap > > with SOLID70 elements. I have done this since assessing the > > convection > > coefficient for the gap isn't straight forward, therefore I'd like > to > > replace > > the convection effect by an equivalent conduction in the solid > > representing > > the gap.
> > Do I have to consider CFD for such a problem, or can I get away with > > proper assumptions ? If not, I guess FLOTRAN would not do the trick > > since > > I am faced with a rotating frame of reference...
> > Any comments or hints on how to model the gap would greatly be > > appreciated ?
> > Best regards.
> > Philippe Vidori > > Technologies M4, Inc. > > 575, rue Le Breton > > Longueuil, QC. J4G 1R9 > > Tel: (450) 674-2030 ext:244 > > Fax: (450) 674-2017 > > Philippe.vidori@t...