Development of 300 kW Class Ceramic Gas Turbine (CGT302)

With the aim of achieving higher efficiency, lower pollutant emissions, and multi-fuel capability for small to medium-sized gas turbine engines for use in co-generation systems, a ceramic gas turbine (CGT) research and development program is being promoted by the Japanese Ministry of International Trade and Industry (MITI) as a part of its “New Sunshine Project”. Kawasaki Heavy Industries (KHI) is participating in this program and developing a regenerative two-shaft CGT (CGT302). In 1993, KHI conducted the first test run of an engine with full ceramic components. At present, the CGT302 achieves 28.8% thermal efficiency at a turbine inlet temperature (TIT) of 1117°C under ISO standard conditions and an actual TIT of 1250°C has been confirmed at the rated speed of the basic CGT. This paper consists of the current state of development of the CGT302 and how ceramic components are applied.

An On-Line System for Heterogeneous Distributed Computing and Advanced Visualization of Test Cell Data

In most turbine engine testing facilities, the tools and techniques of computational fluid dynamics (CFD) and advanced visualization have never been applied to facilitate (near) real-time analysis of the test hardware. New computer software technology has now been applied which allows server-to-client remote procedure calls (RPC), enabling supercomputers to be called from within the online test scanning program. Coupled with advanced visualization software and graphics workstations, it is possible to view the inside of a test while it is being conducted. Such capability can be as valuable to researchers in steering tests as X-rays are to doctors in diagnosing health. This report presents results from a library of software for on-line visualization. Using this system, a full turbomachine (compressor) has been visually analyzed by interpolating pressure instrument rakes to give a full flow field view of the engine (compressor). All data values at each grid cross-section are non-dimensionalized and viewed at varying ranges of iso-distortion surfaces. Regions of low or high energy can be seen as they proceed through the compressor stages. A full range of capabilities are displayed for both pressure and temperature using computer animation techniques recorded to video. Such views are unique and may provide extra information to help understand flow phenomena such as inlet distortion and how it relates, for example, to stall margin. CFD efforts are also described in conjunction with the use of RPC to supercomputers. A stream function meridional, 2D/quasi-3D solution to five blade rows is shown in context with rotating blade rows and shown on video. The value of the computer work is all generic and can be applied in almost any scientific area where on-line computer systems are used.

Use of Knowledge-Based Engineering in Compressor Rotor Design

Competitive pressures are forcing manufacturers of turbine engines to reduce product development times, minimize design iterations, and react rapidly to changing markets and customers. Concurrent Engineering replaces the traditional sequential design process with parallel efforts in multiple disciplines, increasing product quality while reducing leadtime. Knowledge-Based Engineering captures product and process knowledge contained in the “corporate memory” to enhance and accelerate the design process. Linking the two together provides a wide variety of synergistic effects not separately available. In this paper a general description of the process used to create a Knowledge Based Engineering (KBE) System capable of Concurrent Engineering (CE) will be presented, along with selected results. The summary discusses use of the system created to pursue real world design problems.

Development of an Oilless, Gearless, and Bleedable Under Armor Auxiliary Power Unit

The oilless, gearless and bleedable under armor auxiliary power unit (UAAPU) development program is providing the United States Army with a technically advanced auxiliary power unit (APU) for military tracked vehicles. Fully functional prototypes in two configurations are being demonstrated in both laboratory and field tests. The APU power output is 32 kw (43 shp) with 10 to 20 kw supplied as electrical power and the balance of power delivered as elevated pressure bleed air for use in conjunction with the vehicle nuclear, biological, and chemical (NBC) filtration and environmental control system (ECS). The design of the UAAPU incorporates air bearings and a shaft-speed permanent-magnet starter/generator with electronic power conditioning to eliminate completely the need for oil lubrication and an auxiliary gearbox. This significantly simplifies the mechanical design of the APU with resulting reliability, durability, and maintainability improvements. Over 600 hours of laboratory system development test time has been logged and 90 hours in field tests on an M1A1 main battle tank. Operations in the field have included both gunnery and simulated warfare training exercises.

Life Cycle Considerations in Propulsion Alternatives for Fast Vessels

Fast vessels are being built and operated for a large range of passenger carrying applications. Fast cargo carrying vessels are being considered in a variety of sizes as well. A major decision in design and construction of these vessels is the propulsion system; this decision has major impacts on the operation economics as well as the operational capabilities of the vessels. Factors involved in consideration of propulsion alternatives for fast vessels are examined, with emphasis upon the total life cycle operating implications of these factors. A methodology for considering the factors is suggested, and an example is presented with results of the consideration tradeoffs.

An Evaluation of Indentation and Finishing Properties of Bearing Grade Silicon Nitrides

This paper describes the results of studies of the machining performance and the indentation hardness and fracture toughness of different silicon nitride materials as part of an effort to better define the optimum machining conditions for bearing components. This work builds on prior efforts by two of the authors, Gardos and Hardisty (1993) who formulated a simple relationship between diamond grinding performance of silicon nitride bearing balls and a wear equation first detailed by Evans and Wilshaw (1976). The goal of this present work was to determine the general applicability of such a relationship, i.e. could simple indentation studies be used to define finishing conditions for different silicon nitride materials. The availability of such a simple test would reduce the time required for developing an acceptable process when a supplier changes his formulation, or when a new material becomes available. Quicker development of optimum finishing conditions would eventually result in a lower-cost product for users. The initial study by Gardos and Hardisty (1993) was based on limited data taken at a fixed set of conditions. This study expanded the range of conditions evaluated and the number of ceramic materials studied in an effort to define the universality of the relationship between grinding wear, hardness and toughness. This study has shown that no simple relationship like that first envisioned by the authors exists. The results showed that the grinding wear of the individual silicon nitride materials increased at different rates as a function of load. Because of the differences found in the load dependence of grinding rates, no simple relationship between hardness, fracture toughness and grinding rate could be found which fit the data over the range of conditions studied. This work is part of an ARPA funded effort to provide a tribological performance database on ceramic bearing materials, including their grinding and finishing properties, and their interaction with standard bearing steels.

The Westinghouse/Rolls-Royce WR-21 Gas Turbine Variable Area Power Turbine Design

The Westinghouse/Rolls-Royce WR-21 marine gas turbine with an intercooled, recuperated thermodynamic cycle utilises exhaust heat to provide excellent efficiency not only at full power but also at part power. Vital to the success of the engine and the optimisation of fuel consumption is the Variable Area Nozzle (VAN) which is used to control turbine capacity across the power range. By continuously monitoring and controlling turbine capacity, the heat recovered by the recuperator is optimised across the power range. The efficiency of the power turbine variable stage at low power (low flow) and its ability to deliver full power (high flow) is vital to the success of the engine. Success also requires precise control of the variable vane, easy maintenance and good reliability in a hot, mechanically hostile environment. This paper describes the aerodynamic and mechanical design, rig verification and early engine experience of the variable power turbine stage.

ICR Gas Turbine Update

The Intercooled, Recuperated (ICR) marine gas turbine development program is a U.S. Navy program to design, develop, and qualify an engine for propulsion of future surface ships. This paper provides a brief description of the program objectives, technical requirements, design overview, and status of development program and the test program currently underway. The engine system being developed is designated the WR-21 and is being designed in accordance with a detailed technical specification issued by the U.S. Navy.

Progress on the AGATA Project: A European Ceramic Gas Turbine for Hybrid Vehicles

The European EUREKA project EU 209 or AGATA - Advanced Gas Turbine for Automobiles is a program dedicated to the development of three critical ceramic components; i. catalytic combustor, ii. radial turbine wheel, iii. static heat exchanger, designed for a 60 kW turbogenerator hybrid electric vehicle. The objective is to develop and test the three components as a full scale feasibility study with an industrial perspective. The AGATA partners represent car manufacturers as well as companies and research institutes in the turbine, catalyst and ceramic material fields in France and Sweden. The program has been running since early 1993 with good progress in all three sub-projects. The turbine wheel design is now completed. FEM calculations indicate that the maximum stress occur during cold start and is below 300 MPa. Extensive mechanical testing of the Si3N4 materials from AC Cerama and C&C has been performed. The catalytic combustor operates uncooled at 1350°C. This means a severe environment for both the active catalyst and the ceramic honeycomb substrates. Catalysts with high activity even after aging at 1350°C have been developed. Ceramic honeycomb substrates that survive this temperature have also been defined. The catalytic combustor final design is ready and the configurations which will be full scale tested have been selected. The heat exchanger will be a ceramic recuperator with 90 % efficiency. Both a tube concept and a plate concept have been studied. The plate concept has been chosen for further work. Sub-scale plate recuperators made of either cordierite or SiC have been manufactured by C&C and tested.

GE LM2500 Gas Turbine Enters Commercial Marine Service in Aquastrada Class Ships

This paper reviews the highlights of the first two seasons of commercial operation of GE LM2500 gas turbines installed in the Aquastrada class of fast ferries. The ships’ total propulsion systems were supplied and packaged by MTU-Friedrichshafen for this first commercial marine application of the LM2500 gas turbine. Problems encountered and lessons learned are presented as part of the paper.