Response and Flow Characteristics of an Angular Momentum Flowmeter

Area of Science:

• Aerospace Engineering
• Fluid Dynamics
• Mechanical Engineering

Background:

• Accurate aviation fuel flow measurement is critical for commercial flight safety and efficiency.
• Existing flowmeters face challenges in dynamic response and measurement range.
• Angular momentum flowmeters offer a potential solution but require detailed operational understanding.

Purpose of the Study:

• To design a visualization platform for observing internal component dynamics in angular momentum flowmeters.
• To simulate the dynamic rotation of rotors and calculate deflection angles under varying flow conditions.
• To elucidate the operational mechanism and identify areas for structural optimization.

Main Methods:

• Utilized a sliding mesh method combined with an angular momentum algorithm for dynamic simulation.
• Developed a visualization platform to observe component responses.
• Conducted experimental analysis to categorize flow regimes based on spring behavior.

Main Results:

• Identified three flow regimes: pre-spring, single-spring, and dual-spring, based on spring response.
• Observed stable upstream rotor rotation at 1.1 rad/s at 0.091 kg/s flow rate.
• Demonstrated that flat spring configurations improve measurement limits and high-pressure zone stability by dissipating secondary vortices.

Conclusions:

• The study provides a clear understanding of angular momentum flowmeter operational mechanisms.
• The flat spring design enhances performance by extending the lower measurement limit and stabilizing operation.
• Findings offer a theoretical foundation for future structural optimization of these flowmeters.