Emissions and new technology programs for conventional spark-ignition aircraft engines

A long-range technology plan in support of general aviation engines was formulated and is being implemented at the Lewis Research Center. The overall program was described, and that part of the program that represents the in-house effort at Lewis was presented in detail. Three areas of government and industry effort involving conventional general-aviation piston engines were part of a coordinated overall plan: (1) FAA/NASA joint program, (2) NASA contract exhaust emissions pollution reduction program, and (3) NASA in-house emissions reduction and new technology program

An overview of NASA intermittent combustion engine research

This paper overviews the current program, whose objective is to establish the generic technology base for advanced aircraft I.C. engines of the early 1990's and beyond. The major emphasis of this paper is on development of the past two years. Past studies and ongoing confirmatory experimental efforts are reviewed, which show unexpectly high potential when modern aerospace technologies are applied to inherently compact and balanced I.C. engine configurations. Currently, the program is focussed on two engine concepts the stratified-charge, multi-fuel rotary, and the lightweight two-stroke diesel. A review is given of contracted and planned high performance one-rotor and one-cylinder test engine work addressing several levels of technology. Also reviewed are basic supporting efforts, e.g., the development and experimental validation of computerized airflow and combustion process models, being performed in-house at Lewis Research Center and by university grants

Compound cycle engine program

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded power plant which combines the lightweight pressure rise capability of a gas turbine with the high efficiency of a diesel. When optimized for a rotorcraft, the CCE will reduce fuel burned for a typical 2 hr (plus 30 min reserve) mission by 30 to 40 percent when compared to a conventional advanced technology gas turbine. The CCE can provide a 50 percent increase in range-payload product on this mission. A program to establish the technology base for a Compound Cycle Engine is presented. The goal of this program is to research and develop those technologies which are barriers to demonstrating a multicylinder diesel core in the early 1990's. The major activity underway is a three-phased contract with the Garrett Turbine Engine Company to perform: (1) a light helicopter feasibility study, (2) component technology development, and (3) lubricant and material research and development. Other related activities are also presented

Design and fabrication of noncondensing radiator for environmental evaluation of space power mercury Rankine system

Conceptual and mechanical design analyses, and fabrication of noncondensing radiator for environmental testing of space power mercury Rankine syste

Preliminary evaluation of a compound cycle engine for shipboard gensets

The results of a thermodynamic cycle (SFC) and weight analysis performed to establish engine configuration, size, weight and performance are reported. Baseline design configuration was a 2,000 hour MTBO Compound Cycle Engine (CCE) for a helicopter application. The CCE configuration was extrapolated out to a 10,000 MTBO for a shipboard genset application. The study showed that an advanced diesel engine design (CCE) could be substantially lighter and smaller (79% and 82% respectively) than todays contemporary genset diesel engine. Although the CCE was not optimized, it had about a 7% reduction in mission fuel consumption over today's genset diesels. The CCE is a turbocharged, power-compounded, high power density, low-compression ratio diesel engine. Major technology development areas are presented

Investigation of a 0.6 hub-tip radius-ratio transonic turbine designed for secondary-flow study I : design and experimental performance of standard turbine

Detailed design information including overall performance parameters, velocity diagrams, and blade surface velocities is presented. Experimental performance includes maps based on rating as well as total-pressure ratios showing the effect of exit whirl. Also included are results of surveys at the stator exit and downstream of the rotor at design speed and specific work. This information will be used as a standard for comparison with subsequent secondary-flow work

NACA Research Memorandums

Report presenting a low-velocity-turning stator designed to reduce secondary-flow loss cores by turning the flow at low velocities and accelerating it in passages of constant flow angle with reduced cross-channel pressure gradients. Turbine performance was measured to determine the effect of low-velocity turning in the stator on the overall turbine performance. Results regarding the stator performance, overall turbine performance, and rotor exit surveys are provided

NACA Research Memorandums

Report presenting an investigation of a transonic turbine with a 0.6 hub-tip radius ratio in order to determine the effect of stator and rotor secondary flows on turbine performance. Results regarding the overall performance, stator exit surveys, and rotor exit surveys are provided

NACA Research Memorandums

Memorandum presenting a low-velocity-turning stator designed to reduce secondary-flow loss cores by turning the flow at low velocities and accelerating it in passages of constant flow angle with reduced cross-channel pressure gradients. Performance of the stator was determined with static-pressure measurements and detailed surveys of total pressure and flow angle made with the turbine operating at design speed near design work