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The purpose of this paper is to outline the potential usage of ceramic engines in combination with other technologies as a possible propulsion contender for future aerospace applications.

The possibility of enabling novel propulsion systems in aerospace engineering is examined through a multilateral review study concerning ceramic engines and a proposed design approach. In view of the benefits and challenges of employing ceramic engines as possible candidates for the sustainable solutions of the future, a fundamental design proposal is presented for a conceptual generic unmanned air vehicle (GUAV).

The findings of this article identify a number of useful scenarios for future ceramic engine applications and considerations.

It is imperative to emphasize that this conceptual article solely sheds light on a limited number of key ideas associated with ceramic engines and their possible applications. Thus, many new areas may emerge and impact the application of ceramic engines in light of more in‐depth conceptual studies.

Implications of ceramic engine utilization in aeronautical applications may result in enhanced performance characteristics and less operational costs. Further implications could possibly be extended to various naval/automotive applications and new configurations of transportation vehicles.

The paper aims to generate an interest amongst younger individuals and environmental aware enthusiasts to consider ceramic engines for transportation applications to a greater extent than before.

The implementation of this particular conceptual design results in a synergistic ceramic engine combination with a hybrid airship design in novel aeronautical applications.

This paper seeks to evaluate the potential of heat exchanged aeroengines for future Unmanned Aerial Vehicle (UAV), helicopter, and aircraft propulsion, with emphasis placed on reduced emissions, lower fuel burn, and less noise.

Aeroengine performance analyses were carried out covering a wide range of parameters for more complex thermodynamic cycles. This led to the identification of major component features and the establishing of preconceptual aeroengine layout concepts for various types of recuperated and ICR variants.

Novel aeroengine architectures were identified for heat exchanged turboshaft, turboprop, and turbofan variants covering a wide range of applications. While conceptual in nature, the results of the analyses and design studies generally concluded that heat exchanged engines represent a viable solution to meet demanding defence and commercial aeropropulsion needs in the 2015‐2020 timeframe, but they would require extensive development.

As highlighted in Parts I and II, early development work was focused on the use of recuperation, but this is only practical with compressor pressure ratios up to about 10. For today's aeroengines with pressure ratios up to about 50, improvement in SFC can only be realised by incorporating intercooling and recuperation. The new aeroengine concepts presented are clearly in an embryonic stage, but these should enable gas turbine and heat exchanger specialists to advance the technology by conducting more in‐depth analytical and design studies to establish higher efficiency and “greener” gas turbine aviation propulsion systems.

It is recognised that meeting future environmental and economic requirements will have a profound effect on aeroengine design and operation, and near‐term efforts will be focused on improving conventional simple‐cycle engines. This paper has addressed the longer‐term potential of heat exchanged aeroengines and has discussed novel design concepts. A deployment strategy, aimed at gaining confidence with emphasis placed on assuring engine reliability, has been suggested, with the initial development and flight worthiness test of a small recuperated turboprop engine for UAVs, followed by a larger recuperated turboshaft engine for a military helicopter, and then advancement to a larger and far more complex ICR turbofan engine.

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

This paper aims to compare the performance, emission and combustion characteristics of E20 biodiesel with diesel-water emulsion and eucalyptus water emulsion.

This research expounds the trans-esterification process apparently. Various biodiesel blends were made to go through the trans-esterification process to make it suitable for feeding them into the low heat rejection (LHR) engine. E20 biodiesel – 20% of eucalyptus oil by volume with diesel was chosen to carry out the research as it was found to be the best blend with diesel. The volume of water content in diesel water emulsions was varied by 5, 10 and 15% in DWM1 (Diesel Water Mixture1), DWM2 (Diesel Water Mixture2) and DWM3 (Diesel Water Mixture3), respectively. Similarly, the volume of water content in eucalyptus water emulsions was varied with emulsification ratio of E20 biodiesel. Partially stabilized zirconia was coated over top surface of the piston and valve facing of the LHR engine.

From the researches carried out, DWM3 (Diesel Water Mixture3) was found to be superior when compared with other diesel-water emulsions in LHR engine. The overall efficiency was found to be higher for EWM3 than other biofuels tested the in LHR engine.

This investigational experiment can be further extended to multi-cylinder engine and to improve the cetane number, Di ethyl ester (DEE) fuel additives can be added.

In the development of engine components a number of special techniques are used to combat the hostile operating environment which usually includes high and cyclic forces, high and cyclic temperatures, sliding and often corrosion and/or erosion. Examples of the use of these techniques, namely the development of special materials for substrate and surface, of mathematical modelling verified by telemetry, and of special machining, to solve the problems of the operating environment, are given in respect of piston rings, cylinder liners, bearings, camshafts and valve seat inserts. It is noted that of these techniques the development of special surface and substrate materials provides the most assistance. The application of materials technology to surface and substrate is illustrated with respect to ceramics, including silicon nitride, silicon carbide, zirconia and alumina. Applications underdevelopment include insulation, improvement of wear resistance, reduction of mass, increase of operating temperature and the reinforcement of metals, for example reinforcement of aluminium alloys using alumina fibres incorporated by squeeze casting. The several means open to improve the properties of gravity cast aluminium silicon alloys are reviewed and the improvement of properties obtained by squeeze casting without reinforcement are illustrated. The further enhancement of these properties by the design of an appropriate fibre reinforcement system, incorporated by squeeze casting, is then described. Its application to the reinforcement of a combustion bowl subject to high thermal stress is discussed and the performance of the resulting piston in relation to unreinforced pistons is described. In conclusion the market, product and process aspects of the development are correlated to demonstrate its overall value and to identify further applications.

In the development of engine components a number of special techniques are used to combat the hostile operating environment which usually includes high and cyclic forces, high and cyclic temperatures, sliding and often corrosion and/or erosion. Examples of the use of these techniques, namely the development of special materials for substrate and surface, of mathematical modelling verified by telemetry, and of special machining, to solve the problems of the operating environment, are given in respect of piston rings, cylinder liners, bearings, camshafts and valve seat inserts. It is noted that of these techniques the development of special surface and substrate materials provides the most assistance. The application of materials technology to surface and substrate is illustrated with respect to ceramics, including silicon nitride, silicon carbide, zirconia and alumina. Applications under development include insulation, improvement of wear resistance, reduction of mass, increase of operating temperature and the reinforcement of metals, for example reinforcement of aluminium alloys using alumina fibres incorporated by squeeze casting. The several means open to improve the properties of gravity cast aluminium silicon alloys are reviewed and the improvement of properties obtained by squeeze casting without reinforcement are illustrated. The further enhancement of these properties by the design of an appropriate fibre reinforcement system, incorporated by squeeze casting, is then described. Its application to the reinforcement of a combustion bowl subject to high thermal stress is discussed and the performance of the resulting piston in relation to unreinforced pistons is described. In conclusion the market, product and process aspects of the development are correlated to demonstrate its overall value and to identify further applications.

The purpose of this paper is to develop a novel process of integral ceramic molds for investment casting of hollow turbine blades.

At first, a resin pattern of a hollow turbine blade prototype is fabricated by stereolithography (SL). And then aqueous gelcasting process is utilized to fill the resin pattern with ceramic slurry of low viscosity and low shrinkage, through in situ polymerization of the slurry a ceramic mold is formed. At last, the ceramic mold for investment casting of hollow turbine blade is obtained by vacuum drying, pyrolyzing and sintering.

An integral ceramic mold is successfully fabricated by combining SL and gelcasting process, cores and shell are connected with each other and thus high relative position accuracy is guaranteed. Properties of integral ceramic mold at room temperature and high temperature satisfy the requirements of directional casting for complex‐shaped thin‐walled blades.

Because the integral ceramic mold is a close body, it is very difficult to directly measure its inner dimensions and the relative position accuracy of cores and shell, and the further research is needed.

This method enhanced the versatility of using SL prototype in the fabrication of integral ceramic mold for investment castings. Although this paper took a hollow turbine blade as an example, this method is also capable of fabricating integral ceramic molds for other complex investment castings.

Heat transfer and stress analysis in metallic and coated exhaust valves are performed by an adaptive space‐time finite element method. Results indicated that coatings of ordinary thickness cannot protect a coated valve operating in an uncooled engine. A new approach for designing the inner geometry of the metallic part in a coated hollow valve is presented. The purpose of the cavity is changed from cooling to insulating. Controlling the valve temperature and the heat flows out is done by changing the geometry of the cavity. The optimum is sought between the hollow geometry of the valve and its coating thickness while the outer geometry is that of an ordinary valve. Exhaust valves with optimal geometry are presented. A reduction of 40% of the heat flows out is obtained, compared to the heat flows out from a metallic valve operating in a cooled engine. By comparison, reduction of the heat flows out from a coated, ordinary geometry valve amounts to only 20%.

The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite (CMC) components used in gas-turbine engines are commonly protected with so-called environmental barrier coatings (EBCs). EBCs typically consist of three layers: a top thermal and mechanical protection coat; an intermediate layer which provides environmental protection; and a bond coat which assures good EBC/CMC adhesion. The materials used in different layers and their thicknesses are selected in such a way that the coating performance is optimized for the gas-turbine component in question.

Gas-turbine engines, while in service, often tend to ingest various foreign objects of different sizes. Such objects, entrained within the gas flow, can be accelerated to velocities as high as 600 m/s and, on impact, cause substantial damage to the EBC and SiC/SiC CMC substrate, compromising the component integrity and service life. The problem of foreign object damage (FOD) is addressed in the present work computationally using a series of transient non-linear dynamics finite-element analyses. Before such analyses could be conducted, a major effort had to be invested toward developing, parameterizing and validating the constitutive models for all attendant materials.

The computed FOD results are compared with their experimental counterparts in order to validate the numerical methodology employed.

To the authors’ knowledge, the present work is the first reported study dealing with the computational analysis of the FOD sustained by CMCs protected with EBCs.

Westland Aerospace Division has delivered its first orders for the laser cable marking system, developed by Westland. The orders, worth about £350,000, include one for Boeing Corporation.