Log in

Login to your account

Username *
Password *
Remember Me

Create an account

Fields marked with an asterisk (*) are required.
Name *
Username *
Password *
Verify password *
Email *
Verify email *
Captcha *
Reload Captcha

AFT Blog

Welcome to the Applied Flow Technology Blog.
Ben Keiser

What Does “Head (HGL)” Mean for Submerged Pumps and Exit Pressures?

In AFT Fathom and AFT Impulse, it is possible to model a submerged pump where a short and possibly frictionless suction pipe for the pump’s inlet does not need to be modeled.  When modeling a submerged pump, there are two options available for specifying the system inlet boundary condition at the pump suction.  As shown in Figure 1 below, the Submerged Pump’s Suction Pressure can either be specified as “Head (HGL)” or “Pressure”.   Modeling a submerged pump is not the only time where the “Head (HGL)” or “Pressure” choices will arise.  If an Exit Valve (i.e., a valve that discharges...
Continue reading
  5246 Hits
  0 Comments
Ben Keiser

When Should You Use Variable Pipe Resistance?

Have you ever finished running an AFT Impulse model and then received the following Warning message shown in Figure 1 and then wondered what it means? During a waterhammer analysis, the flowrates are constantly changing all throughout the system, therefore, the velocities and Reynold's numbers are also constantly changing.  The friction factors will also be constantly changing during the transient.  By default, AFT Impulse will use the friction factors that are obtained during the steady-state analysis and then use the same friction factors during the transient and they will be assumed to remain constant. Since it is possible for the flowrates...
Continue reading
  2842 Hits
  0 Comments
© 2021 Applied Flow Technology