Hannah Shacter, CFD Intern

Email: cessyone@aol.com

This research project is focused on pump design when spatial constraints are severe.  In many engineering applications a pump is squeezed into a space that forces the designer to break the textbook guidelines for pump design.

In order to study this, we start with a baseline design from an existing system.  We study the performance of several variations of the baseline design to determine the sensitivity of one design option versus another.   Ultimately,  our goal is to run simulations to determine the most efficient design for the pump within the space available.  We also hope to better understand if some design rules for a pump are more crucial than others.

All simulations are run with pressure boundary conditions at the inlet and outlet, and with the impeller spinning at 4800 RPM.  These operating conditions and the mesh for the geometry of the pump are  provided to the simulation package.  The impeller motion is handled explicitly.  All simulations are run until the mass flow at the inlet and outlet are balanced.

 The results posted below show the development of both our design ideas and the results to date. Our pictures are generated by FIRE, a CFD software package. It allows us to simulate the flow of fluid inside the pump and take snapshots of the velocity, pressure and other variables at different points in the simulation.

 

Design Cases	0 kPa Pressure Head	75 kPa Pressure Head	175 kPa Pressure Head	212 kPa Pressure Head
Baseline Pump	-
Inlet A				-
Inlet B	-			-
Inlet C	-			-
Volute A
Volute B	-			-
Volute C	-			-
Inlet A & Volute B	-			-
Inlet B & Volute B	-			-

Detailed results are available for cases with "Blue Pins" (just click on the case or pin you wish to review).
 

• Lab vs. CFD Simulations for Baseline Case
• Different Volutes (assuming no cavitation)
• Different Volutes (with a simple cavitation model)
• Different Inlets (assuming no cavitation)
• Different Inlets (with a simple cavitation model)
• Inlet A & Volute B (with a simple cavitation model)
• Inlet B & Volute B (with a simple cavitation model)

• Although the Baseline Cases meets the original performance goals for the pump at 175 kPa Pressure Head, cavitation is evident at lower pressure heads. For example, at a pressure head of 75 kPa, there is significant cavitation in the two blade passages nearest the cut-off. This is the case even though the inlet pressure is 45 kPa gauge.
• At 175 kPa Pressure Head, the systems studies rank in the following order:
1. Inlet A and Volute B (5.56 L/sec)
2. Inlet B and Volute B (5.30 L/sec)
3. Volute B (4.95 L/sec)
4. Inlet A (4.80 L/sec)
5. Inlet B (4.78 L/sec)
6. Inlet C (4.60 L/sec)
7. Volute C ( 4.55 L/sec)
8. Baseline (4.50 L/sec)
9. Volute A (4.40 L/sec)