Force exerted on a Fixed Vane....Plz help?

[nanunath]

Hi everyone....:)


Consider :- "The general Impulse momentum equation for a Control Volume"

F = M1+M2

F is the sum of all external forces acting on the Control volume{CV}...
so applying this to a jet impinging on a fixed curved vane ....
I think the external forces on the CV are:
1) End pressure forces [at start and end of the CV...{plz download THIS RAR FILE{2.36MB} (http://www.fzuploads.com/files/10/9/1255081847-sridhar1867-Reference-FM-Streeter.rar.rar) to refer to CV taken here...or any other references needed for this} and the pressure force acting due to the surrounding atmosphere.
2) Force on CV by Vane.{this is alright for me}

But none of the texts ever accounts for the pressure forces exerted on a the CV in case of vane ...WHY arent the pressure forces considered here...

Can anyone help me as to where am I exactly messing up..Plz?.. :( :(..:confused:..:confused:

In the rare case you need any quick revision on the basics plz download THIS RAR FILE {2.3MB} (http://www.fzuploads.com/files/10/9/1255081847-sridhar1867-Reference-FM-Streeter.rar.rar)...In the rar file I have included as to how the "General Control volume conservation equation","General Impulse momentum equation" are derived in the book I use-"FM by V.L.Streeter" and also the section "Force exerted on a vane" .

[I]Any help Welcome....:)

Thanks!...:)