Aircraft noise is a complex topic which is projected to increase with the increasing number of aircraft and size of the engines. Turbine-powered aircraft produce sounds that are considered pollutants at certain decibel levels. Turbofan engines are inherently quieter than turbojet engines for a given level of thrust. The purpose of this research is to determine if current turbofan noise reductio...

As the aerospace industry is moving towards the More Electric Aircraft, there is a growing demand for electrical power to feed the increasing electrical loads in the aircraft. More Electric Aircraft (MEA) and More Electric Engine (MEE) are terms that are sometimes mistakenly being used interchangeably, but that are actually very different. This paper outlines some of the issues that have been c...

The seals are the important component of the aircraft engine to prevent leakage of gas or oil. Because the contact and friction problems have a great influence on the performance of the seals, the concept and theory of tribology is already widely applied in research and design processes of advanced seals. This report selected three kinds of representative seals which are co...

Current practice in the operation and maintenance of an aircraft fleet requires analysis of data obtained from in-service engines in order to identify engine deterioration and provide preventative maintenance. Typically large quantities of engine vibration and performance data are available from various engine-mounted sensors. The analysis of such data requires techniques for modelling these mu...

For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health p...

The high noise levels associated with full-scale military aircraft result in nonlinear propagation, which results in acoustic shock formation and can alter noise perception. This propagation has been modeled for other aircraft but previous studies have been limited in scope, showing results for only select engine conditions and angles. Recent data measured near an F-35B allow for a more complet...

A detection scheme based on the artificial immune system (AIS) paradigm was developed for specific classes of aircraft jet engine failures including throttle, burner fuel flow valve, variable nozzle area actuator, variable mixer area actuator, low-pressure spool speed sensor, low-pressure turbine exit static pressure sensor, and mixer pressure ratio sensor. The Modular Aero-Propulsion System Si...

Exposures to cabin environmental contaminants were measured on 36 commercial transport aircraft. The objectives were to characterize levels of contaminants and evaluate the relationship between flight factors such as aircraft size, occupancy, ventilation, and flight length, and environmental parameters. Monitoring was conducted at two coach locations for the duration of the flight for VOCs, nit...

Contributions from the combustor to the overall propulsion noise of civilian transport aircraft are starting to become important due to turbofan design trends and expected advances in mitigation of other noise sources. During on-ground, static-engine acoustic tests, combustor noise is generally sub-dominant to other engine noise sources because of the absence of in-flight effects. Consequently,...