Pulsation Frequency Analysis (PFA)
An AFT Impulse Add-on Module
This module helps engineers identify and avoid resonant frequencies in systems, especially
in those caused by positive displacement pumps. Problems can arise when the
frequencies that are excited by pulsation are at or near the acoustic resonant
frequencies of a fluid system. The module is used to calculate the
acoustic resonance frequencies that could damage system equipment.
The AFT Impulse Pulsation Frequency Analysis module helps:
- Avoid system weakening or failure
- Reduce operating and maintenance costs
- Minimize disruptions in production processes
The AFT Impulse PFA module lets you:
- Predict and understand resonant frequencies in systems that use positive displacement pumps so they can be avoided in operation
- Graphically show the frequency response of a system to a simulated pulse
- Ensure the pressure pulsation magnitudes comply with the API-674 Standard
- Work with existing AFT Impulse models
The module automates most of the pulsation analysis process using a series of steps:
1. Build the model in AFT Impulse
2. Specify the characteristics of the pulse
3. Apply the forcing function to the source of the pulse
4. Run the model
5. Generate a Bode plot, displaying Frequency vs. Magnitude
For PD Pump pulsations:
6. Specify excitation frequencies to analyze from specific pump RPM
7. Generate child scenarios for each selected excitation pump RPM
8. Run each child scenario and determine resulting acoustic magnitudes
9. Automatically compare peak-to-peak pressure pulsation to API 674 requirements
2. Specify the characteristics of the pulse
3. Apply the forcing function to the source of the pulse
4. Run the model
5. Generate a Bode plot, displaying Frequency vs. Magnitude
For PD Pump pulsations:
6. Specify excitation frequencies to analyze from specific pump RPM
7. Generate child scenarios for each selected excitation pump RPM
8. Run each child scenario and determine resulting acoustic magnitudes
9. Automatically compare peak-to-peak pressure pulsation to API 674 requirements