2D quad/tri mesh
 

Hi guys i want too simulate a compressor piston system with dynamic meshing both smoothing and remeshing methods so i need to use hybrid mesh,say i have a simple square box that half of it meshed with quad and the rest with tri mesh,i used this approach first i created a block and split the block into 2 blocks then i deleted one of the blocks and mesh the other blocks with quad mesh,then i used surface meshing for the other block,and saved the mesh and load it when icem prompt i select merge, but when i read the mesh in fluent it gives me error,i have problem in merging the meshes i think,can anyone please help me? How can i mesh my geometry with quad/tri mesh?

I had some progress but stil unable to merge the meshesh,the interior between the to meshes will appear as wall in fluent,can anyone help please?