regarding meshing an airfoil
 

hi every one
i'm trying to mesh an airfoil (which has a cylinder above its upper surface), i have done most of it ,but i'm not satisfied with the blocking stratgey i have used ..and i'm also not sure the way i used ogrid is correct..
and what actually happens when we create a ogrid by selecting external blocks and what happens when we create it using internal blocks?? if both are same which one i should prefer ???
i have attached here my project file
looking forward for a reply

What do you think about this ...

thanks for the reply
i tried the way you used the blocking strategy but i couldnt get it .
after splitting the cylinder should i merge the vertices with the vertices which come from splitting the airfoil ?

FAR hoping for your reply

regarding meshing an airfoil
 

i tried using your blocking strategy, i got most of it ,but i cant get this linearity..
plz help me with this

you have merged the vertices, dont do it. Start with O-grid and make the splits as required. For example I made two o-grid splits for the cylinder.

Also you can choose the C-type blocking by collapsing the block at trailing edge.

Thaks a lot