# Hey, fluent doesnt work !

 Register Blogs Members List Search Today's Posts Mark Forums Read

 February 10, 2004, 08:07 Hey, fluent doesnt work ! #1 Javier Guest   Posts: n/a Hello: I work with sails, and i use it as parachute. I think in this case all the force over the surface must be from viscous terms ( no too much ciculation arround the sail appear), but when i make a force report the viscous force is very smaller than the pressure force. Does anyone knows why? Other problem is that the pressure force on the sail and the sail shadow are of the same direction, and i think they must pe opossite. When this problem appear i put a wall in a down stream inviscid flow, and the Dalambert paradox doesnt appear, There was force!. There are too many things i dont understand. Can anyone help me please? Thanks

 February 10, 2004, 09:55 Re: Hey, fluent doesnt work ! #2 Jonas Larsson Guest   Posts: n/a On a parachute the pressure force is certainly several orders of magnitude larger than the viscous force... the code seems to be right. Viscous forces are only dominating in cases where you have symmetric streamlined bodies without any separation. Note that the bodies need to be symmetric also, otherwise viscosity (or numerical viscosity if you use an inviscid solver) will always setup circulation which in turn generates pressure forces.

 February 10, 2004, 15:17 Re: Hey, fluent doesnt work ! #3 Javier Guest   Posts: n/a Too much thanks. I´ve been studing the problem and with your contribution, i´m afraid i solve the stuff.

 March 11, 2004, 10:56 Re: Hey, fluent doesnt work ! #4 yogesh and amit Guest   Posts: n/a hi, this is because in an inviscid solver, we use numerical viscosity of a very low value. we also encountered this problem while analysing the inviscid flow over airfoils..... we have made a 1d nozzle flow analyser and working on a 2d airfoil analysis code...that gives the Cp curves and Cd,Cl too. we want to know the the best scheme.and some references too. we are sophomores from india.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post MASOUD FLUENT 4 April 9, 2012 13:23 enry Fluent UDF and Scheme Programming 16 September 9, 2010 02:44 Prakash.Paudel ANSYS 0 August 12, 2010 12:07 Joseph CFX 14 April 20, 2010 15:45 Stanislav Sviderek FLUENT 1 July 28, 2008 17:21

All times are GMT -4. The time now is 07:13.