Research papers

Subsonic Single Aft Engine (SUSAN) Flight Deck Experiment: Throttle and Engine Display Concepts

NASA is developing a new hybrid-electric aircraft concept called the SUbsonic Single Aft eNgine (SUSAN) Electrofan. The SUSAN airplane is being designed as a 180-passenger commercial regional jet and is expected to fly i…

Initial Regulatory and Certification Approach for the SUSAN Electrofan Concept

New aircraft concepts and associated technologies are required to meet emerging environ-mental impact goals, while still meeting established airworthiness certification standards and regulations.

Identification and dual adaptive control of a turbojet engine

The objective of this paper is to utilize the design methods of modern control theory to realize a 'dual-adaptive' feedback control unit for a highly non-linear single spool airbreathing turbojet engine.

Icing research tunnel test of a model helicopter rotor

An experimental program has been conducted in the NASA Lewis Research Center Icing Research Tunnel (IRT) in which an OH-58 tail rotor assembly was operated in a horizontal plane to simulate the action of a typical main r…

Dual Engine application of the Performance Seeking Control algorithm

The Dual Engine Performance Seeking Control (PSC) flight/propulsion optimization program has been developed and will be flown during the second quarter of 1993.

Turbine bypass engine: A new supersonic cruise propulsion concept

Engine performance and mission studies were carried out for a single-spool Turbine Bypass Engine concept. Comparisons were made between the TBE, a conventional single-spool turbojet, and the Pratt & Whitney Variable Stre…

Turbine bypass engine - A new supersonic cruise propulsion concept

Engine performance and mission studies were carried out for a single-spool turbine bypass engine (TBE) concept. Comparisons were made between the TBE, a conventional single-spool turbojet, and the Pratt and Whitney Varia…

Comparison of predicted engine core noise with current and proposed aircraft noise certification requirements

Predicted engine core noise levels for subsonic CTOL aircraft engines are compared with measured total aircraft noise levels and to current and proposed federal noise certification requirements.

A Noise and Emissions Assessment of the N3-X Transport

Analytical predictions of certification noise and exhaust emissions for NASA's N3-X - a notional, hybrid wingbody airplane - are presented in this paper.

The effect of ambient conditions on the emissions of an idling gas turbine

Changes in ambient conditions - pressure, temperature, and humidity - affect the exhaust emissions of a gas turbine engine. Such variations must be compensated for during engine certification.

Multi-Partner Experiment to Test Volcanic-Ash Ingestion by a Jet Engine

A research team of U.S. Government agencies and engine manufacturers are designing an experiment to test volcanic-ash ingestion by a NASA owned F117 engine that was donated by the U.S. Air Force.

System Analysis and Performance Benefits of an Optimized Rotorcraft Propulsion System

The propulsion system of rotorcraft vehicles is the most critical system to the vehicle in terms of safety and performance. The propulsion system must provide both vertical lift and forward flight propulsion during the e…

General aviation turbine engine /GATE/ concepts

The paper deals with only a portion of the work done by Williams Research Corporation for NASA. It provides a look at possible new-generation powerplants that offer the potential for remarkable airplane performance gains…

Intelligent Engine Systems Work Element 1.2: Malfunction and Operator Error Reduction

Jet engines, although highly reliable and safe, do experience malfunctions that cause flight delays, passenger stress, and in some cases, in conjunction with inappropriate crew response, contribute to airplane accidents.…

The Effects of Hot Corrosion Pits on the Fatigue Resistance of a Disk Superalloy

The effects of hot corrosion pits on low cycle fatigue life and failure modes of the disk superalloy ME3 were investigated. Low cycle fatigue specimens were subjected to hot corrosion exposures producing pits, then teste…

Ultra-High Bypass Engine Aeroacoustic Study

A system study was carried out to identify potential advanced aircraft engine concepts and cycles which could be capable of achieving a 5 to 10 EPNdB reduction in community noise level relative to current FAR36 Stage 3 l…

Noise Certification Predictions for FJX-2-Powered Aircraft Using Analytic Methods

Williams International Co. is currently developing the 700-pound thrust class FJX-2 turbofan engine for the general Aviation Propulsion Program's Turbine Engine Element.

Bifurcation techniques for nonlinear dynamic analysis of compressor stall phenomena

Compressor stall phenomena is analyzed from nonlinear control theory viewpoint, based on bifurcation-catastrophe techniques. This new approach appears promising and offers insight into such well known compressor instabil…

Helicopter propulsion system reliability and engine monitoring assessments

The major short life, unreliable, and high maintenance engine and power components and subsystems in current civil helicopters were identified.

NASA/Pratt and Whitney experimental clean combustor program: Engine test results

A two-stage vorbix (vortex burning and mixing) combustor and associated fuel system components were successfully tested in an experimental JT9D engine at steady-state and transient operating conditions, using ASTM Jet-A …

Teledyne Continental Motors emissions data and analysis and flight test results

Five different engine models were tested covering combinations of all engine categories in current production in the range from 100 to 435 brake horsepower.

An overview of SAE ARP 1587: Aircraft gas turbine engine monitoring system guide

A systematic approach to developing an engine monitoring system (EMS) is outlined. An extensive shopping list of EMS capabilities and benefits are included.

Pollution reduction technology program for turboprop engines

The reduction of CO, HC, and smoke emissions while maintaining acceptable NO(x) emissions without affecting fuel consumption, durability, maintainability, and safety was accomplished.

The convertible engine: A dual-mode propulsion system

A variable inlet guide vane (VIGV) convertible engine that could be used to power future high-speed rotorcraft was tested on an outdoor stand.

Life prediction technologies for aeronautical propulsion systems

Fatigue and fracture problems continue to occur in aeronautical gas turbine engines. Components whose useful life is limited by these failure modes include turbine hot-section blades, vanes and disks.

Life prediction technologies for aeronautical propulsion systems

Fatigue and fracture problems continue to occur in aeronautical gas turbine engines. Components whose useful life is limited by these failure modes include turbine hot-section blades, vanes, and disks.

Turbofan engine demonstration of sensor failure detection

In the paper, the results of a full-scale engine demonstration of a sensor failure detection algorithm are presented. The algorithm detects, isolates, and accommodates sensor failures using analytical redundancy.