Trouble with Mesh in a 2D Y-pipe
 

Hello, guys, I need some guidance here. I need to simulate air-water flow in a 2D pipe using Ansys Fluent in order to obtain void fraction and pressure losses, and I'm having a lot of trouble constructing the mesh. The said pipe has a small Y section, where the air and water will mix, and a 7180mm long rectangle, where the flow will develop. I haven't been able to generate a structured mesh with inflation layers (i will use the k-epsilon standard turbulence model). My first attempt was with the Multizone method, total thickness inflation, and face meshing, but it failed. Then, I tried the quadrilateral dominant method and sizing with bias (elements growing from the boundary to the middle) in both inlets and outlet, but it also failed. I watched some videos and read some manuals, but they didn't help me: everything that I tried failed. You guys are my last hope! How can I generate a structured mesh with inflation layers in my pipe?
OBS: Attached to this message are the pictures of the pipe.