I realise this may be preliminary design, but ultimately do you have haccess to CFD or a windtunnel? A picture of the shape gives a general idea but conveys no useful information as to performance.
Cyrus' last post is dead right, you do need to have a clear idea of where you are going before even considering putting pen to paper for a proper drawing. Your initial drawing was fair enough to give us a general idea, but you've changed it now with seemingly no real reason.
Try and answer the following questions regarding the last picture.
Why have you changed the design?
Will that be better?
How do you know?
Unless you can give a comprehensive answer to all of those questions, dont change anything and dont draw anything because its meaningless if you dont know where you are heading.