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Technical Paper

Initial Testing of a 250 KW Starter/Generator for Aircraft Applications

The work reported in this paper has been conducted by a team from GE-Aircraft Engines, GE-CR&D, and Sundstrand under a contract sponsored by the USAF, Wright Laboratories, WPAFB, Contract No. F33615-90-C-2052. The objective of this contract is to prove the feasibility of an Integral Starter/Generator (IS/G) through the preliminary design stage and demonstrate the starter/ generator technology in the externally mounted version utilizing switched reluctance machine technology. This paper will report on the progress for the EIS/G-system through the initial testing stage. Comparison of the finished hardware with the design results presented earlier will lead of the paper. This is followed by the discussion of the early testing results for the system testing. Recommendation on additional testing will be presented at the end of the paper.
Technical Paper

SP-100 Initial Startup and Restart Control Strategy

Recent Generic Flight System (GFS) updates have necessitated revisions in the initial startup and restart control strategies. The design changes that have had the most impact on the control strategies are the addition of the Auxiliary Cooling and Thaw (ACT) system for preheating the lithium filled components, changes in the reactivity worths of the reflectors and safety-rods such that initial cold criticality is achieved with only a small amount of reflector movement following the withdrawal of the safety-rods, and the removal of the scram function from the reflectors. Revised control and operating strategies have been developed and tested using the SP-100 dynamic simulation model, ARIES-GFS. The change in the total reactivity worths of the reflectors and safety-rods has eliminated the need for the use of fast and slow reflector drive speeds during the initial on-orbit approach to criticality.
Technical Paper

SP-100 Controller Development Paradigm

To facilitate the development of the Space Reactor Power System (SRPS) controller, a rapid prototyping and multi-phased development methodology is being utilized. The rapid prototyping environment used in the development models both the controller and the system being controlled. Since the validation of the SRPS control strategies is a long lead activity to ensure the required safety and control features, the SRPS controller development is carried out in phases, starting with normal modes of operation and followed by transient and off-normal modes. In every phase, the rapid prototyping of the control strategies is used (1) to establish well-defined controller requirements, (2) to perform fast identification of changes and refinement of the strategies, and (3) to conduct in-phase correction and optimization of the strategy and component development.
Technical Paper

Re-Establishment of RTG Unicouple Production

The approach that was utilized to start up and requalify manufacture of the thermoelectric unicouple devices for the Cassini RTG (Radioisotope Thermoelectric Generator) program are described in this paper. Key elements involved in this effort were: engineering review of specifications; training of operators; manufacturing product verification runs; and management review of results. Appropriately, issues involved in activating a fabrication process that has been idle for nearly a decade, such as upgrading equipment, adhering to updated environmental, health, and safety requirements, or approving new vendors, are also addressed. The cumulative results of the startup activities have verified that a production line for this type of device can be reopened successfully.
Technical Paper

Quiet Clean Short-Haul Experimental Engine (QCSEE) Design Rationale

The principal design features of the NASA QCSEE UnderThe-Wing and Over-The-Wing powered lift propulsion systems are given. In the UTW engine, these include noise reduction features, a variable pitch low pressure ratio fan, a fan drive reduction gear, an advanced core and low pressure turbine with a low pollution combustor, a digital control, and advanced composite construction for the inlet, fan frame, fan exhaust duct, and variable area fan exhaust nozzle. The OTW engine is similar but has higher fan pressure and a fixed pitch fan. Both engines are scheduled to be fabricated and tested starting in 1976.
Technical Paper

Development of Hot-Isostatically Pressed and Forged P/M Rene 95 for Turbine Disc Application

Previous studies had demonstrated the economic and technical feasibility of producing high-quality forgings for aircraft turbine engine parts from hot-isostatically pressed (HIP) Rene 95 powder billets. The present program was aimed at developing a production practice for making HIP + forged turbine discs. The major goal was improved product fabricability and reliability with minimum cost. The program was conducted using argon atomized Rene 95 powder. Experimental studies were conducted to evaluate the effect of powder characteristics, HIP parameters, preform design, and forging conditions on forgeability, microstructure, and mechanical properties. The results of these studies were incorporated into a pilot production run in which 10 disc forgings were made and evaluated. The selected process involved the consolidation of -60 mesh powder to full density by hot-isostatic pressing at a temperature above the γ' solvus temperature.
Technical Paper

Optimizing the Design of the Battery-Starter/Generator System

Aircraft starting and generating systems heretofore have been largely the result of joining together available components. Recent studies have demonstrated that substantial benefits in weight, cost, size, and performance may be realized through a total system approach. This paper identifies the types of information required, and the methods of system analysis employed, to design an optimized system.
Technical Paper

A New Reaction Control Approach for Sounding Rockets

This paper concerns a new technique designed to provide high performance reaction control systems for sounding rockets. Proportional control of differential thrust and simple adaptive control of thrust magnitude (based on the level of demanded thrust) is utilized. The control is being implemented with a combination of electronic and fluidic components for an Aerobee 150 sounding rocket payload whose goal is a pointing stability of 0.1 arc second.
Technical Paper

Storable Fuel Cell Powerplants for Undersea Applications

Storable powerplants are needed in many applications of submerged ocean systems. On the basis of cost effectiveness alone, it is shown that storable fuel cell powerplants for fixed and slowly moving mobile systems offer significant advantages over a range from 0.005 to 30 kW in the mission energy range from 0.01 to 100 megawatt-hr. Analysis of high pressure gaseous storage (compatible with deep submergence hulls) shows significant fuel storage volume advantages over storage of cryogenic hydrogen and oxygen. A unique hybrid fuel storage system, using LOX and high pressure hydrogen at LOX temperature shows reduced displacement, compared to both gaseous and pure cryogenic systems, for modest endurance periods. Long term storage involves substantial volume penalties for cryogenic reactants. High pressure gas storage may, however, be substantially excelled on a storage volume basis by solid reagents used to produce hydrogen and oxygen for the fuel cell as needed.
Technical Paper

The GE Electric Vehicle

This paper discusses some of the objectives, results, and implications of GE's electric vehicle and component systems developments to date. The experimental vehicle is covered in detail. The vehicle's styling, construction, materials, power system, operating costs, and performance are discussed with some alternatives and attendant economic considerations. The paper also presents a brief discussion of the power system requirements, performance, and economics of several potential electric vehicles as well as a critique of the potential power sources presently announced as having promise for electric vehicle propulsion. The paper includes pictures, tables, and graphs describing the experimental vehicle and illustrating the points discussed relative to other potential vehicles, power systems, batteries, and fuel cells.
Technical Paper

A Hydromechanical Transmission Development

This paper describes the results of the first step of a planned development program to produce a family of split path hydro-mechanical transmissions for military applications. The HMT-250 hydromechanical transmission has given superior performance, unlimited ability to change ratio without affecting service life, and a control system with the advantages of variable ratio. The control system and testing programs are described in detail.