# Problem building 3D Panel Method

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

 September 15, 2006, 07:51 Problem building 3D Panel Method #1 Daniel Guest   Posts: n/a Hi! I'm building a matlab 3D panel method; one with constant source/doublet panels (using Dirichlet BC) other with constant doublet panels using Neumann BC). The Neumann code has an error of to high pressure coef. on places where it shold be lowest (the sphere should have CPmin -1.25, but mine is around 0.5). This means that the speed is actualy decreasing over top or lower sides of an airfoil!!! The collocation points are placed in center of weight of panel and final velocities are calculated there as well. Calculation of doublet strenghts I consider correct since their strengths make some logic. Dirichlet code plotes improper results as well. Maybe the problem could be in DeltaL expression for tangential velocities calculations in which I had no correction? (please refer to Katz, Plotkin Page357). There is another problem concerning both codes, that is sensitivity to grid! I get best results (I know it is risky to call it better when the code is flawed on actual wing when there is no tip fill. But anyhow, there are huge gradients on wing tip trailing edge. Please let us talk about this subject for a while. I couldn't find ANYWHERE a 3D panel code so this could be my graduate work and therefore free for use. The only reference I'm using and I could find is Katz, Plotkin: Low-Speed Aerodynamics Thank you very much! Daniel

 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 Canesin OpenFOAM Installation 137 January 20, 2016 15:56 Gerrit Groot Main CFD Forum 17 September 17, 2007 09:13 gocarts Main CFD Forum 2 April 22, 2007 22:50 sam NUMECA 5 February 24, 2006 09:04 Waleed Mohamed Main CFD Forum 2 March 30, 1999 21:26

All times are GMT -4. The time now is 23:32.