ImpulseMomentum Principle
THIS INTERACTIVE JAVA APPLET WAS DEVELOPED AT UT AUSTIN BY Kyle Douglas AND Lino Geo Lino Bailey, UNDER THE SUPERVISION OF PROFESSOR. Spyros A. Kinnas, 1998.
PERMISSION TO LINK TO THIS JAVA APPLET AND TO DOWNLOAD OR TO USE THE RELATED JAVA SOURCE CODE, MUST BE GRANTED BY PROFESSOR Spyros A. Kinnas ( kinnas@mail.utexas.edu ).
Purpose:
This applet calculates and draws the force vector due to the reaction of
the pipe on the fluid. The equations used to determine the magnitude and direction
of the force are based on the ImpulseMomentum principle and Bernouli's equation.
Assumptions:
 The pressure distribution is uniform at any crosssection of the pipe
 The center of pressure for any crosssection is the midpoint of that section
 The velocity distribution is also uniform for any given crosssection
Using the applet:
Note: The pipe is not drawn to scale! In order to make the components of the applet
a reasonable size, some of the variables (like the diameter and radius of curvature)
are scaled in different proportions. However, components which measure similar
parameters are scaled equally. For example, the weight is scaled in the same proportion
as the force on the fluid, and the entrance diameter is scaled equally to the exit diameter.
 Select the type of pipe to use, horizontal or vertical
 Change the pipe geometry by dragging the yellow, circular handles at the corners of the pipe
 Change the entrance velocity by dragging the yellow, square handle on the velocity vector
 Translate the pipe around the screen by dragging the handle with the black arrows
 Enter values to more accurately change the parameters of the problem. The range for each
parameter is:
 Rotation of pipe: 0180 degrees
 Radius of pipe bend: 3060 cm
 Exit diameter: 713 cm
 Entrance and exit pressure (gage): 30100 kPa
 Entrance velocity: 110 m/s
A Note About the Vectors:
To avoid confusion, the vectors and what they describe are given below.
 The Velocity and Weight vectors simply give the magnitude and direction of the velocity
and weight
 The Force of Pipe vector gives the magnitude and direction of the force on the fluid due
to the pipe
 The Force of Pressure vector shows the force acting on the entrance and exit sections
of the pipe due to fluid pressure
 Finally, the Momentum vector shows the magnitude and direction of the term
rQV for the entrance and exit sections of the pipe

Last Revised: August 9, 1998