Need advice about meshhing grooved channel
 

The geometry which is given in below is a flow problem in heated channel. Upper wall is heated. Bottom edge is not symmetry line it is wall. I need advice about meshing this geometry.

http://dl.dropboxusercontent.com/s/0...4%B1z.png?dl=0

Here is my trial

http://dl.dropboxusercontent.com/s/6...07.14.png?dl=0

Y-grid for triangles, quad for rectangle