JFET_V9_N1_RP2 Yasser Rihan Journal on Future Engineering and Technology 2230 – 7184 9 1 27 31 Plunger, Pump, Leakage, Numerical, Modeling In this paper a numerical model for calculating plunger pump leakage is introduced. This model involves calculating the velocity profile for an annulus with the inner wall moving parallel to the outer wall. The calculated average velocity for the annular fluid is used to predict the fluid slippage. The new method for the slippage agrees with published formula at the same operating conditions. The numerical model is used to predict the fluid slippage at different operating conditions. August - October 2013 Copyright © 2013 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=2480