Contraction and expansion coefficient

[Karin&Bethi]

Dear Chris,

thank you for your help again!

Another little question:
F.e. we have two cross sections. The first one is a very narrow one and the second is wider. Where do we have to place the Expansioncoefficient. In the cross section description of the first or of the second cross section?

Thank you in advance,
yours sincerely
Karin and Bethi

[Chris Maeder]

Dear Karin and Bethi:

Note that the contraction / expansion coefficient is defined at the cross section upstream of the reach in which the contraction or expansion occurs at. Therefore, this coefficient is used to account for the contraction / expansion losses in the next downstream reach.

Sincerely,

Chris E. Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com