## [Libmesh-users] L2 projection of boundary values

 [Libmesh-users] L2 projection of boundary values From: Lorenzo Botti - 2007-04-03 15:55:44 ```Another question... Why don't you use L2 projection of the boundary values in ex13? We tryed this way of imposing boundary conditions in our navierstokes solver but we found small non-zeroes velocity vectors propagating on sides where we imposed zeroes constraints. Have you ever seen this problem? Thanks again for any help... Lorenzo Chiacchiera con i tuoi amici in tempo reale! http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com ```

 [Libmesh-users] L2 projection of boundary values From: Lorenzo Botti - 2007-04-03 15:55:44 ```Another question... Why don't you use L2 projection of the boundary values in ex13? We tryed this way of imposing boundary conditions in our navierstokes solver but we found small non-zeroes velocity vectors propagating on sides where we imposed zeroes constraints. Have you ever seen this problem? Thanks again for any help... Lorenzo Chiacchiera con i tuoi amici in tempo reale! http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com ```
 [Libmesh-users] L2 projection of boundary values From: John Peterson - 2007-04-03 16:10:23 ```Lorenzo Botti writes: > Another question... > Why don't you use L2 projection of the boundary values in ex13? > We tryed this way of imposing boundary conditions in our navierstokes > solver but we found small non-zeroes velocity vectors propagating on > sides where we imposed zeroes constraints. > Have you ever seen this problem? > > Thanks again for any help... For the lid-driven cavity with discontinuous BCs, a true L2 projection of the boundary conditions usually results in alternating in/outflow at the top element. We do full L2 projection of BCs in example 18, however. -John > > Lorenzo > > ```