What is the technical name for the shape of an airship? How would I find the volume of that shape?

What is the technical name for the shape of an airship? How would I find the volume of that shape?

Not an answer to your question, but definitely some good info can be found on the Goodyear Blimp website. [1]

The shape is a spheroid. The volume is (4/3)*pi*(a^2)*b. Where a is the horizontal radius and b is the vertical radius.