Effect of pump efficiency on transient results

Question

Hi, all 
 I want to ask about the effect of pump efficiency on the transient calculations, as when i change the pump efficiency curve i found that the results of pump speed changed. but i don't know where the efficiency term used in transient calculation. 
 Thank You 
 Mohamed Salah 
 Water Resources Engineer

Jesse Dringoli · Answer

Mohammed, 
 
The pump's efficiency will likely have an effect on the transient results if the transient pump type is set to variable speed with the control type set to Torque, or if it is set to Shut after Time Delay. The efficiency influences the shaft power which effects the shaft torque, which (per your previous post/thread) will effect the pump speed in these cases.. 
 
References: 
 
 www.engineeringtoolbox.com/pumps-speed-torque-d_1114.html 
 www.engineeringtoolbox.com/pumps-power-d_505.html 
Fluid Transients in Systems, Wylie, 1993, pg. 146