How to calculate that shape inside volume?

[gaber2611]

Dear everybody here,

please i need help at that attached image of round shape as shown,

my questions is what is the formula which used for calculating the volume of that shape?, the cylinder of D1, and D2, , easily can be calculated by (Pi/4*D2*L), so how about in the middle?

will appreciate your replies,

Thanks in advance

 

[SteamKing]

The transition piece in the middle is called the 'frustum of a right circular cone'.

The formula for its volume is given here:

http://jwilson.coe.uga.edu/emt725/Frustum/Frustum.cone.html

 

[gaber2611]

Great, thank you so much Steamking, sound you're real king :)