Hi Mr. Rob, If I use, linear pattern option, the contact region is formed in the mesh option. Similarly, If i am using slice option, then again contact region is formed in the mesh option. if delete in mesh option, then using dynamic option in the solution setup, by making a coupling option I am getting 4 walls ( nWhat I used approach in the past is that I am deleting all contact regions in the mesh option and naming them manually like ( Air inlet, Air outlet, Air symmetry, Air interface) for air zone while for Licl zone (Licl inlet, Licl outlet, Licl symmetry, Licl interface). In mesh interface option under Solution setup above dynamic mesh option, by coupling wall I am getting two wall ( one and other is shadow) But in this case on increasing thickness of wall nothing is showing. I am using ANSYS 16.2nnI am struck in this problem. I am looking for ward your kind help which is highly appreciable.nnThanks in advance.nRegards,nAbbas n