Hi, i cant get Nektar++ to work with 3D meshes containing tetrahedrons or any other 3D elements with triangular faces. The problem occurs when the local base vertex is the vertex with the largest angle. I first suspected a bug in the APESolver but noticed that the problem occurs with the NavierStokesCFE system as well. The ADRSolver is not affected as far as i can tell. I appended four test cases to demonstrate the problem. Two APE cases with two prismatic elements with the local base vertex in the right angle vertex (APE_3DChannel_1LPrismX_laxFri.xml) and in the 45° angle vertex (APE_3DChannel_1SPrismX_laxFri.xml). The two ther cases use the NavierStokesCFE equations on hexahedrons and prisms. Is there something wrong with my cases setup or is this something that isnt working in nektar++? Cheers, Kilian -- Kilian Lackhove, M.Sc. Fachgebiet für Energie- und Kraftwerkstechnik L1|08 114 Technische Universität Darmstadt Jovanka-Bontschits-Straße 2 D-64287 Darmstadt Germany Tel.: +49 6151 16 - 5186 Fax: +49 6151 16 - 6555 e-mail: lackhove@ekt.tu-darmstadt.de