You should create some partitions in order to simplify the geometry.

Franco

how do I create the partition ?

even for curved surfaces I should make partition 

hello ,

yes I don't know if u have experience with  ICEM ,but there under blocks icons u can divide ur mesh into multiple blocks and mesh it manually to define no of nodes per each edge,etc . then u can check the mesh quality for 3x3x3 determinant set the minimum value to -1 in the bounds ,u must have all the cells above 0 to avoid negative cells. 

from my experience ,negative cells or zero face area cells are really annoying the solution will diverge ,so you better remesh ur model manually or automatically using ANSYS mesher to avoid -ve cells.