ORCID

0000-0002-0823-2872

Keywords

aeromechanics, flutter, piezoelectric, vibration

Abstract

Flutter in turbomachinery poses significant risks to aerospace systems, requiring accurate identification of flutter boundaries to ensure operational safety. Traditional binary “flutter / no flutter” testing methods provide limited data without error margins. Aeromechanical Identification Methodology (AIM) offers a safer alternative by mapping aeromechanical damping across operational conditions using non-contact excitation. However, current AIM actuators are constrained to excitation frequencies below 500 Hz, limiting their effectiveness and applicability. To bridge this gap, this research analyzed and validated performance of a novel piezoelectric-based oscillatory flow injection valve (NOVA) designed to deliver high-bandwidth, high-authority actuation for expanded flutter boundary mapping.

NOVA was tested using high-pressure nitrogen on a benchtop rig, with its performance evaluated across various frequencies, pressures, and stroke lengths. Benchtop results indicated the valve has expanded authority and bandwidth (more than 100%) relative to prior actuation technologies. NOVA's performance was repeatable, though authority depended on frequency. At individual frequencies, authority was approximately linear with voltage amplitude. Additionally, the pressure differential measured in the valve exit bore was linear with respect to authority, which is critical for realistic measurement capabilities during on-engine testing.

For comparison with experimental results and to guide future design refinement and engine integration, 2D axisymmetric and 3D simulations were developed in COMSOL Multiphysics. These model valves simulated optimal performance using prescribed pintle motion to investigate dynamics and verified the governing relationships influencing performance across a range of actuation frequencies, stroke lengths, and supply pressures.

This work characterized performance of a novel piezoelectric-based, oscillatory flow actuator capable of extending the operational range of AIM testing. By doubling, and possibly tripling, the usable frequency range and enabling deployment in high-stiffness engine regions, this piezoelectric-based flow valve addresses critical limitations in current testing methods. Expanding flutter boundary testing enhances turbomachinery safety, modeling accuracy, and performance evaluation capabilities.

Completion Date

2026

Semester

Spring

Committee Chair

Jeffrey L. Kauffman

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Mechanical and Aerospace Engineering

Format

PDF

Document Type

Dissertation

Identifier

DP0053244

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