Research on Application of Melt-Growth Composite Ceramics to Gas Turbines

Author(s):  
Kenji Fujiwara ◽  
Narihito Nakagawa ◽  
Kenji Kobayashi ◽  
Shinya Yokoi ◽  
Tsutomu Kihara ◽  
...  

An unique ceramic material produced through unidirectional solidification with eutectic composition of two-phase oxides was introduced recently. This composite material has the microstructure of coupled networks of two single crystals interpenetrate each other without grain boundaries. Depending on this microstructure this material, called Melt Growth Composite (MGC), can sustain its room temperature strength up to 1,700 (near its melting point) and offer strong oxidization-resistant ability, making its characteristics quite ideal for the gas turbine application. Our research project on MGC started in 2001 with the objective of establishing component technologies for MGC application to the high temperature components of the gas turbine engine. This paper outlines the results of our research so far at the early stage of the project.

Author(s):  
P. A. Phillips ◽  
Peter Spear

After briefly summarizing worldwide automotive gas turbine activity, the paper analyses the power plant requirements of a wide range of vehicle applications in order to formulate the design criteria for acceptable vehicle gas turbines. Ample data are available on the thermodynamic merits of various gas turbine cycles; however, the low cost of its piston engine competitor tends to eliminate all but the simplest cycles from vehicle gas turbine considerations. In order to improve the part load fuel economy, some complexity is inevitable, but this is limited to the addition of a glass ceramic regenerator in the 150 b.h.p. engine which is described in some detail. The alternative further complications necessary to achieve satisfactory vehicle response at various power/weight ratios are examined. Further improvement in engine performance will come by increasing the maximum cycle temperature. This can be achieved at lower cost by the extension of the use of ceramics. The paper is intended to stimulate the design application of the gas turbine engine.


Author(s):  
Robert A. Wilson ◽  
Daniel B. Kupratis ◽  
Satyanarayana Kodali

The Department of Defense and NASA have funded a major gas turbine development program, Integrated High Performance Turbine Engine Technology (IHPTET), to double the power density and fuel economy of gas turbines by the turn of the century. Seven major US gas turbine developers participated in this program. While the focus of IHPTET activity has been aircraft propulsion, the same underlying technology can be applied to water craft and terrestrial vehicle propulsion applications, such as the future main battle tank. For these applications, the gas turbines must be equipped with recuperators. Currently, there is no technology roadmap or set of goals to guide industry and government in the development of a next generation recuperator for such applications.


2016 ◽  
Vol 138 (06) ◽  
pp. 38-43
Author(s):  
Lee S. Langston

This article discusses various fields where gas turbines can play a vital role. Building engines for commercial jetliners is the largest market segment for the gas turbine industry; however, it is far from being the only one. One 2015 military gas turbine program of note was the announcement of an U.S. Air Force competition for an innovative design of a small turbine engine, suitable for a medium-size drone aircraft. The electrical power gas turbine market experienced a sharp boom and bust from 2000 to 2002 because of the deregulation of many electric utilities. Since then, however, the electric power gas turbine market has shown a steady increase, right up to present times. Coal-fired plants now supply less than 5 percent of the electrical load, having been largely replaced by new natural gas-fired gas turbine power plants. Working in tandem with renewable energy power facilities, the new fleet of gas turbines is expected to provide reliable, on-demand electrical power at a reasonable cost.


Author(s):  
Douglas A. Pennell ◽  
Mirko R. Bothien ◽  
Andrea Ciani ◽  
Victor Granet ◽  
Ghislain Singla ◽  
...  

This paper introduces and presents validation of the Constant Pressure Sequential Combustion system (denoted CPSC), a second generation concept developed for and applied to the new Ansaldo GT36 H-class gas turbine combustors. It has evolved from the well-established sequential burner technology applied to all current GT26 and GT24 gas turbines, and contains all architectural improvements implemented since original inception of this engine frame in 1994, with beneficial effects on the operation turndown, fuel flexibility, on the overall system robustness, and featuring the required aspects to stay competitive in the present day energy market. The applied air and fuel management therefore facilitate emission and dynamics control at both the extremely high and low firing temperature ranges required for existing and future Ansaldo gas turbine engine classes.


Author(s):  
J. D. MacLeod ◽  
W. Grabe

The Machinery and Engine Technology (MET) Program of the National Research Council of Canada (NRCC) has established a program for the evaluation of sensors to measure gas turbine engine performance accurately. The precise measurement of fuel flow is an essential part of steady-state gas turbine performance assessment. Prompted by an international engine testing and information exchange program, and a mandate to improve all aspects of gas turbine performance evaluation, the MET Laboratory has critically examined two types of fuel flowmeters, Coriolis and turbine. The two flowmeter types are different in that the Coriolis flowmeter measures mass flow directly, while the turbine flowmeter measures volumetric flow, which must be converted to mass flow for conventional performance analysis. The direct measurement of mass flow, using a Coriolis flowmeter, has many advantages in field testing of gas turbines, because it reduces the risk of errors resulting from the conversion process. Turbine flowmeters, on the other hand, have been regarded as an industry standard because they are compact, rugged, reliable, and relatively inexpensive. This paper describes the project objectives, the experimental installation, and the results of the comparison of the Coriolis and turbine type flowmeters in steady-state performance testing. Discussed are variations between the two types of flowmeters due to fuel characteristics, fuel handling equipment, acoustic and vibration interference and installation effects. Also included in this paper are estimations of measurement uncertainties for both types of flowmeters. Results indicate that the agreement between Coriolis and turbine type flowmeters is good over the entire steady-state operating range of a typical gas turbine engine. In some cases the repeatability of the Coriolis flowmeter is better than the manufacturers specification. Even a significant variation in fuel density (10%), and viscosity (300%), did not appear to compromise the ability of the Coriolis flowmeter to match the performance of the turbine flowmeter.


2021 ◽  
Author(s):  
Illia Petukhov ◽  
Taras Mykhailenko ◽  
Oleksii Lysytsia ◽  
Artem Kovalov

Abstract A clear understanding of the heat transfer processes in a gas turbine engine bearing chamber at the design stage makes it possible to properly design the lubrication and sealing systems and ensure the future bearing safe operation. The heat transfer coefficient (HTC) calculated based on the classical Newton-Richman equation is widely used to represent the heat transfer data and useful for the thermal resistance analysis. However, this approach is only formally applicable in the case of a two-phase medium. While there is a need to model a two-phase medium, setting the flow core temperature correctly in the Newton-Richman equation is an issue that is analyzed in this study. The heat from the flow core is transferred to the boundary of the oil film on the bearing chamber walls by an adjacent air and precipitating droplets. The analysis showed that droplet deposition plays a decisive role in this process and significantly intensifies the heat transfer. The main contribution to the thermal resistance of internal heat transfer is provided by the oil film. In this regard, the study considers the issues of the bearing chamber workflow modeling allowing to determine the hydrodynamic parameters of the oil film taking into account air and oil flow rates and shaft revolutions. The study also considers a possibility to apply the thermohydraulic analogy methods for the oil film thermal resistance determination. The study presents practical recommendations for process modeling in the bearing chamber.


Author(s):  
Geoffrey D. Woodhouse

The gas turbine engine has been examined as a power plant for military tracked vehicles for over 30 years. Advocates have stressed the potentially high power density and high reliability as factors in favor of the turbine. Several turbine engines have been evaluated experimentally in military tracked vehicles resulting in a better understanding of such aspects as response characteristics and air inlet filtration requirements. Moreover, although the small volume and light weight of aircraft derivative gas turbines have certain virtues, it generally has been concluded that some form of waste heat recuperation is essential to achieve an acceptable level of fuel consumption, despite the increased weight and volume incurred. The selection of the AVCO Lycoming AGT1500 recuperated gas turbine as the power unit for the U.S. Army new M1 “Abrams” main battle tank was a major milestone in the evolution of gas turbine engines for tank propulsion.


Author(s):  
James Anthony Kluka ◽  
David Gordon Wilson

One of the significant problems plaguing regenerator designs is seal leakage resulting in a reduction of thermal efficiency. This paper describes the preliminary design and analysis of a new regenerative heat-exchanger concept, called a modular regenerator, that promises to provide improved seal-leakage performance. The modular regenerator concept consists of a ceramic-honeycomb matrix discretized into rectangular blocks, called modules. Separating the matrix into modules substantially reduces the transverse sealing lengths and substantially increases the longitudinal sealing lengths as compared with typical rotary designs. Potential applications can range from small gas-turbine engines for automotive applications to large stationary gas turbines for industrial power generation. Descriptions of two types of modular regenerators are presented including sealing concepts. Results of seal leakage analysis for typical modular regenerators sized for a small gas-turbine engine (120 kW) predict leakage rates under one percent for most seal-clearance heights.


Author(s):  
J. E. Donald Gauthier

This paper describes the results of modelling the performance of several indirectly fired gas turbine (IFGT) power generation system configurations based on four gas turbine class sizes, namely 5 kW, 50 kW, 5 MW and 100 MW. These class sizes were selected to cover a wide range of installations in residential, commercial, industrial and large utility power generation installations. Because the IFGT configurations modelled consist of a gas turbine engine, one or two recuperators and a furnace; for comparison purpose this study also included simulations of simple cycle and recuperated gas turbine engines. Part-load, synchronous-speed simulations were carried out with generic compressor and turbine maps scaled for each engine design point conditions. The turbine inlet temperature (TIT) was varied from the design specification to a practical value for a metallic high-temperature heat exchanger in an IFGT system. As expected, the results showed that the reduced TIT can have dramatic impact on the power output and thermal efficiency when compared to that in conventional gas turbines. However, the simulations also indicated that several configurations can lead to higher performance, even with the reduced TIT. Although the focus of the study is on evaluation of thermodynamic performance, the implications of varying configurations on cost and durability are also discussed.


1973 ◽  
Vol 95 (3) ◽  
pp. 191-198 ◽  
Author(s):  
D. J. White ◽  
P. B. Roberts ◽  
W. A. Compton

In recent years automotive engine emissions have become subject to stringent Federal legislation. The most severe of these regulations pertains to the 1976 Emission Standards as defined by the Advanced Automotive Power Systems (AAPS) Division of the Environmental Protection Agency (EPA). A unique combustor concept has been developed by Solar which has demonstrated the feasibility of meeting these emission requirements. The integrated emissions of a typical regenerative gas turbine engine employing this combustor type were each below one half of the levels specified by the Federal 1976 Standards, when tested over a simulated federal driving cycle. The success of the feasibility tests for this combustor concept has lead to more fundamental studies and the planned development of a prototype combustor for demonstration on the EPA-AAPS baseline gas turbine engine. The prototype combustor for the baseline engine is described together with its variable area port mechanisms, which has been demonstrated as necessary for emission control.


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