||November 15, 2008 11:22
help for runner efficiency and working head
hi,all i am working on the efficiency of the runner, but when i calculated the head from the pressure of the inner and outer, why it is lower than the actrual head? the formula is H=Î"p/gρï¼Œand Î"p=Pin-Pout , how can i calculate the loss head? by the way, i doubt my boundary condition is wrong .according to the N11-Q11 curve , i made the model by the appropriate opening of blade and vane, than i set the massflow of inner ,and outflow of the outer. but i can not sure the base of the atmosphere. does anyone can show me the proper method? my leader will quit me if i can not deal ! thank a lot!!!!