The Study of Noise, Vibrations, and Harshness of a Gas Turbine for Unmanned Aerial Vehicle

Primary Faculty Mentor’s Name

Dr. Valentin Soloiu

Proposal Track

Student

Session Format

Poster

Abstract

The efficiency of rotating of shafts of aero derivative turbines are dependent upon numerous factors such as, but not limited to, the type of fuel, the ratio of power output to power input, how the power is transmitted, and how the components of engine interact with each other. The Engine and Combustions Laboratory of Georgia Southern University’s Mechanical Engineering Department is working towards improving the efficiency of gas turbines fueled with alternative fuels. The fuel properties are determined by a viscometer and thermo-gravimetric/differential temperature analyzer while the combustion process is analyzed by instruments and thermodynamics principles. Supplementary, important aspects of combustion effects are analyzed such as: the noise, vibrations, and harshness (NVH). The NVH analysis will be conducted using Jet A, JP 8 and Carinata biofuel.

NVH, a non-intrusive method of determining combustion excitation within the system, is using state of the art measuring instruments by taking the noise level and the vibrating motion and mapping their signals on a frequency spectrum, where abnormal signals are investigated. Higher noise levels are undesirable because they compromise the stealth signature of the Unmanned Aerial Vehicle (UAV) and higher vibrations, which can lead to premature component failure. Analyzing sound and vibration will utilize transducers, which will convert the mechanical energy input to a decipherable electrical output. Sound as a mechanical wave of oscillations will travel through air vibrations and the sound wave will be detected by measuring microphones. Vibration oscillating will be defined by the frequency and amplitude detected by an accelerometer.

Gas turbine’s moving components will produce noise and vibrations, given by the source of excitation. Each component within an engine possess a natural frequency and it is a unique vibration characteristic associated with each component under load at a defined speed. As the engine operates through different speeds, the load characteristics change based on the types of fuel. The point at which the harmonics of the components are no longer unique will be found and the resonance and that leads to amplified vibrations. The detection of resonance through NVH analysis will aid in the development of improvements to either enhance the damping in the system, or set limits to the operation of the turbine to avoid resonance speed. The testing of the different types of fuel will give certitude on the effects on engine components due to the different fuel properties.

Keywords

NVH, Noise, Vibration, Harshness, Turbine, UAV, JP8, Carinata, Biodiesel, Harmonics

Award Consideration

1

Location

Concourse/Atrium

Presentation Year

2014

Start Date

11-15-2014 9:40 AM

End Date

11-15-2014 10:55 AM

Publication Type and Release Option

Presentation (Open Access)

This document is currently not available here.

Share

COinS
 
Nov 15th, 9:40 AM Nov 15th, 10:55 AM

The Study of Noise, Vibrations, and Harshness of a Gas Turbine for Unmanned Aerial Vehicle

Concourse/Atrium

The efficiency of rotating of shafts of aero derivative turbines are dependent upon numerous factors such as, but not limited to, the type of fuel, the ratio of power output to power input, how the power is transmitted, and how the components of engine interact with each other. The Engine and Combustions Laboratory of Georgia Southern University’s Mechanical Engineering Department is working towards improving the efficiency of gas turbines fueled with alternative fuels. The fuel properties are determined by a viscometer and thermo-gravimetric/differential temperature analyzer while the combustion process is analyzed by instruments and thermodynamics principles. Supplementary, important aspects of combustion effects are analyzed such as: the noise, vibrations, and harshness (NVH). The NVH analysis will be conducted using Jet A, JP 8 and Carinata biofuel.

NVH, a non-intrusive method of determining combustion excitation within the system, is using state of the art measuring instruments by taking the noise level and the vibrating motion and mapping their signals on a frequency spectrum, where abnormal signals are investigated. Higher noise levels are undesirable because they compromise the stealth signature of the Unmanned Aerial Vehicle (UAV) and higher vibrations, which can lead to premature component failure. Analyzing sound and vibration will utilize transducers, which will convert the mechanical energy input to a decipherable electrical output. Sound as a mechanical wave of oscillations will travel through air vibrations and the sound wave will be detected by measuring microphones. Vibration oscillating will be defined by the frequency and amplitude detected by an accelerometer.

Gas turbine’s moving components will produce noise and vibrations, given by the source of excitation. Each component within an engine possess a natural frequency and it is a unique vibration characteristic associated with each component under load at a defined speed. As the engine operates through different speeds, the load characteristics change based on the types of fuel. The point at which the harmonics of the components are no longer unique will be found and the resonance and that leads to amplified vibrations. The detection of resonance through NVH analysis will aid in the development of improvements to either enhance the damping in the system, or set limits to the operation of the turbine to avoid resonance speed. The testing of the different types of fuel will give certitude on the effects on engine components due to the different fuel properties.