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Gadolinium zirconate (GZ)-based TBCs comprising GZ as the top layer and yttria stabilized zirconia (YSZ) as the base layer, are attractive double-layered thermal barrier coatings (TBCs) for high temperature gas turbine engine application. This work attempts to understand the influence of individual layer microstructure on the durability of GZ/YSZ double-layered TBCs processed by suspension plasma spray (SPS). Two different spray parameters were chosen to obtain a combination of three microstructurally distinct GZ/YSZ double-layered TBCs i.e. GZ porous (P)/YSZ porous (P), GZ dense (D)/YSZ porous (P) and GZ dense (D)/YSZ dense (D). Thermal diffusivity of the as-deposited coatings was measured using Laser Flash Analysis (LFA) technique and the thermal conductivity of the TBCs was calculated. The GZ/YSZ double-layered TBC specimens were subjected to two different durability tests, i.e. thermal cyclic fatigue (TCF) and burner rig test (BRT). Sintering behavior of the individual layer TBC microstructures was evaluated by comparing the porosity evolution in as-deposited and TCF tested TBCs. Fracture toughness measurements performed on each layer of the double-layered TBCs were correlated with the durability results. Thermal cycling results amply demonstrate that the individual layer microstructure of GZ/YSZ double-layered TBC influenced its durability. Detailed failure analysis of the TCF and BRT failed specimens revealed similar failure modes for GZ (P)/YSZ (P), GZ (D)/YSZ (P) and GZ (D/YSZ (D) TBCs under identical thermal cyclic test conditions. However, failure modes differed when subjected to different thermal cyclic test conditions (TCF and BRT) and the probable causes are discussed. Findings from this work provide key insights on designing durable GZ/YSZ double-layered TBCs. The authors extend their thanks to Mr. Andreas Ottosson from GKN Aerospace AB, Sweden, for performing the burner rig test.

Laser processing of Ti-SiC composite coating on titanium was carried out to improve wear resistance using Laser Engineered Net Shaping (LENS�) - a commercial rapid prototyping technology. During the coating process a Nd:YAG laser was used to create small liquid metal pool on the surface of Ti substrate in to which SiC powder was injected to create Ti-SiC metal matrix composite layer. The composite layers were characterized using X-ray diffraction, scanning and transmission electron microscopy equipped with fine probe chemical analysis. Laser parameters were found to have strong influence on the dissolution of SiC, leading to the formation of TiSi2, Ti5Si3 and TiC with a large amount of SiC on the surface. Detailed matrix microstructural analysis showed the formation of non-stoichiometric compounds and TiSi2 in the matrix due to non-equilibrium rapid solidification during laser processing. The average Young's modulus of the composite coatings was found to be in the range of 602 and 757GPa. Under dry sliding conditions, a considerable increase in wear resistance was observed, i.e., 5.91�10-4mm3/Nm for the SiC reinforced coatings and 1.3�10-3mm3/Nm for the Ti substrate at identical test conditions. � 2011 Elsevier B.V.

航空宇宙技術研究所 12-13 Jun. 1997 東京 日本, National Aerospace Laboratory 12-13 Jun. 1997 Tokyo Japan, HYFLEX(極超音速飛行実験)プロジェクトは、日本の無人軌道機HOPE(H-2ロケット打上げ型有翼回収機)開発用小型実験機シリーズの1つとして計画された。1996年2月12日、実験は成功のうちに行われた。C/C耐熱構造およびセラミックタイル部への飛行中の空力加熱を計測した。本論文では、HYFLEXモデルにおける空力加熱実験を示した。角田研究センタのHEK(中型高温衝撃風洞)で、HYFLEXモデルを試験した。HYFLEXの飛行軌道に沿って試験条件を選択し、これらの実験で得た結果を飛行データと比較した。, The HYFLEX (Hypersonic Flight Experiment) project was planned as one of a series of small-scale experimental vehicles for the development of the Japanese unmanned orbiting plane, HOPE (H-2 Orbiting Plane). The experiment was successfully performed on Feb. 12, 1996. The aerodynamic heating to the region of C/C hot structure and ceramic tile were measured during flight. In this paper, aerodynamic heating experiments on a HYFLEX model are presented. The HYFLEX model was tested in the HEK (High Enthalpy shock tunnel Kakuda), a medium size free-piston shock tunnel at the Kakuda Research Center. Test conditions were selected along the HYFLEX flight trajectory and results obtained in these experiments are compared with flight data., 資料番号: AA0001433024, レポート番号: NAL SP-37

To enable direct experimental duplication of the inflight heat flux distribution on supersonic and hypersonic vehicles, an aerodynamic heating scaling technique has been developed. The scaling technique is based on the analytical equations for convective heat transfer for laminar and turbulent boundary layers that follow from applying the Reynolds analogy. The method was developed starting from an elementary isothermal cold flat plate at zero angle of attack and subsequent introduction of wall temperature effects, geometrical scaling effects and angle of attack effects. The present paper extends the scaling technique by introducing correction factors enabling full duplication of the laminar and turbulent boundary layer heat transfer downstream of a shock wave generated by a flat plate at angle of attack. A similar extension is developed to enable full duplication of the laminar and turbulent boundary layer heat transfer downstream of a Prandt- Meyer expansion. The scaling technique is applied to a simplified vehicle configuration consisting of two convex surfaces. The results clearly show that scaled test conditions can be derived at which the in-flight distribution of heat flux on either one of the two surfaces can be fully duplicated. After implementation of high temperature effects this scaling technique may allow for experimental verification of the heat flux distribution on hypersonic vehicles at supersonic test conditions. In this way, test facilities that are far less expensive to operate can provide valuable information during the initial design phase of a hypersonic vehicle.

Up to now, reduction of fuel consumption of vehicles equipped with CVT transmission has not been exploited to its full potential due to the reduced driveability when driving the optimum efficiency engine operating points. An ISG system with torque boost capabilities can be used to restore this driveability. This paper discusses the goals, the CAE simulation tool, the methodology used in the preparative study for evaluation and dimensioning of a CVT- ISG concept, as well as the simulation results. The conclusions, generated from numerous simulations, provide vital information for the component selection, and for the development of the powertrain management system.

With a rapid increase in size and complexity of software today, the scope of software testing is also expanding. The efficiency of software testing needs to be improved in order to ensure the appropriate delivery deadline and cost of software development. For improving efficiency of software testing, the test needs to be designed in a way that the number of test cases is sufficient and appropriate in quantity. Test analysis is the activity to refine Application Under Test (AUT) into proper size that test design techniques can be applied to. It is for designing the test properly. However, the classification for proper size depends on individual's own judgments. This paper proposes a test analysis method for the black box testing using a test category that is the classification based on fault and AUT knowledge.

This paper summarizes the compilation of information on physical simulations of seabed scouring by ice keels, and the resulting database. Physical simulations are critical for a proper understanding of ice scouring phenomena. A total of 487 scour simulations from twentyeight studies are reported. General information about test facility, soil, keel type, model pipeline, test conditions and results are outlined. The database can be used as a tool to identify knowledge gaps and guide future testing programs, to generate empirical relationships between the parameters involved during this interaction, or to validate numerical models. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE)., 22nd International Offshore and Polar Engineering Conference, ISOPE-2012, June 17-22, 2012, Rhodes, Greece, Series: The proceedings of the ... International Offshore and Polar Engineering Conference

In-cylinder flow field structure in an internal combustion (I.C) engine has a major influence on the combustion, emission and performance characteristics. Fluid enters the combustion chamber of an I.C engine through the intake manifold with high velocity. Then the kinetic energy of the fluid resulting in turbulence causes rapid mixing of fuel and air, if the fuel is injected directly into the cylinder. With optimal turbulence, better mixing of fuel and air is possible which leads to effective combustion. A good knowledge of the flow field inside the cylinder of an I.C engine is very much essential for optimization of the design of the combustion chamber for better performance especially in modern I.C engines like gasoline direct injection (GDI), homogeneous charge compression ignition (HCCI) engines.The main objective of this work is to study the incylinder fluid flow field characteristics of a single-cylinder engine to see the effect of intake manifold inclination at equivalent rated engine speed using Particle Image Velocimetry (PIV) under various static intake valve lift conditions. To facilitate the PIV experiments, the metal cylinder of the engine was replaced by a transparent one. For every operating test condition, 50 image pairs were captured and processed using DAVIS software. From the results, it is seen that the in-cylinder flow structure is greatly influenced by the intake manifold inclinations irrespective of intake valve lift. Maximum Turbulent Kinetic Energy (TKE) was highest at full intake valve lift irrespective of the inclination. Also, the maximum TKE was the highest for 60� intake manifold inclination compared to other inclinations irrespective of the intake valve lift at equivalent rated engine speed. Finally, it is concluding that the analysis carried in this work is useful in predicting the flow and inturn optimizing combustion chamber of modern I.C engines.