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101.
Thermal analysis of a ceramic coating diesel engine piston using 3-D finite element method 总被引:1,自引:0,他引:1
In this study, firstly, thermal analyses are investigated on a conventional (uncoated) diesel piston, made of aluminum silicon alloy and steel. Secondly, thermal analyses are performed on pistons, coated with MgO-ZrO2 material by means of using a commercial code, namely ANSYS. Finally, the results of four different pistons are compared with each other. The effects of coatings on the thermal behaviors of the pistons are investigated. It has been shown that the maximum surface temperature of the coated piston with material which has low thermal conductivity is improved approximately 48% for the AlSi alloy and 35% for the steel. 相似文献
102.
103.
Stratis V. Sotirchos 《Chemical Engineering Communications》1985,39(1):259-276
The effects of thermal radiation on the pseudosteady state and transient behavior of porous char particles exposed to an oxygen containing environment are investigated. The numerical simulation results show that particles that do not interchange radiant energy with their environment are characterized by wider ambient temperature regions where multiple steady states exist, higher combustion rates, and lower burning times 相似文献
104.
本文用不同的测试技术和方法测定了锗酸铋(BGO)单晶的比热(300~800K)热膨胀系数(100~1100K)和导温系数(140~700K),进而导出了 BGO 单晶不同温度下的导热系数、定容比热、德拜温度和格虑内森数。本文还对 BGO 单晶热物理性质的变化规律作了理论解释。 相似文献
105.
W.K ChiuS.T Tan 《Computer aided design》2002,34(13):997-1010
In many applications the location of the centre of gravity of a mechanical part is an important factor that a designer must consider. If it is not in a desired location, a part might not work properly, e.g. unbalanced force might be generated in a rotational part. After a part is modeled, its centre of gravity cannot be altered unless its external shape or internal mass distribution is changed. However, the external shape is usually constrained by other design considerations. In this paper, an algorithm is proposed for controlling the centre of gravity of a hollowed part. Using this algorithm, the location of the centre of gravity of a part is controlled by changing its internal mass distribution. 相似文献
106.
Kazutaka Chibana Chaedong Kang Masashi Okada Koji Matsumoto Tetsuo Kawagoe 《International Journal of Refrigeration》2002,25(2):83
Water-silicone oil emulsion with an additive, (C2H5O)3SiC3H6NH2, was examined as a heat storage material. A spiral tube used as a heat exchanger was immersed in a low temperature bath and the emulsion was circulated in the tube to make ice continuously. Ice was separated from the ice–liquid suspension in an outlet tank. The amount of formed ice, the temperatures of the inlet and the outlet of the heat exchanger, and the temperatures in the tube wall were measured and the overall heat transfer coefficient and the heat flux through the tube were calculated. Experiments were carried out, varying the flow rate, the temperature of cooling brine, and the thickness of tube wall. The condition under which slurry ice was formed continuously without adhesion of ice to the cooling wall was clarified. Though decrease in the thermal resistance of the tube increased the rate of ice formation or raised the brine temperature, it narrowed the range of the flow rate and of the brine temperature in which slurry ice was formed continuously. 相似文献
107.
The objective of the present study is to develop multi-functioned coating to the components, which are made of copper with electroplated Ni and are widely used for steel making industry. In this paper, we report the mechanical and thermal properties of Ni based superalloys with carbide sprayed by high velocity oxygen fuel (HVOF), and the detailed effects of sprayed material, spraying conditions, and initial powder structure on these properties. It was found that, among commercial Ni self-fluxing alloys (without fusing treatment), coating with a carbon content of 0.58 mass% had the most preferable properties, with a good balance of the hardness, strength, and thermal shock resistance. The thermal shock resistance depended not only on the strength of the coating but also on the volume contraction when tested at high temperatures. For the several developed Ni based superalloys with carbide, Ni20Cr8Mo5Fe–WC and Ni16Cr15Mo3–WC demonstrated the prominent adhesion strength and thermal shock resistance with high Galvanic corrosion resistance through optimized spraying condition. Also, 20 mass% NiCr–Cr3C2 coating sprayed by using employed relatively small primary particle succeeded in achieving the multi-superior properties; high adhesion strength, high corrosion resistance and thermal shock resistance. 相似文献
108.
The aim of the present paper is to study the effect of gravity on visco-elastic surface waves in solids. The wave velocity
equations are deduced from Biot’s theory of initial stress on the assumption that gravity creates a type of initial stress
— hydrostatic in nature. Resulting equations are used to investigate surface waves of the Rayleigh, Love and Stoneley types.
Results are in good agreement with corresponding classical results when gravity and viscosity are neglected. 相似文献
109.
夏季 ,室外气候诸因素经过不同途径 ,对室内的影响会有差异。了解这些差异有助于在设计时把握主要问题。讨论在住宅隔热设计中 ,针对不同的室内条件 ,应优先考虑的因素及相应的设计对策。 相似文献
110.
在3次采油过程中,注采已为广泛应用,但所面临的问题是如何确定油层中注入流体的波及范围、流体前缘位置及推进速度等。利用地震方法进行注采由于受震资料分辨率的限制,只适用于浅层,而其它测井方法由于探测范围限制,揭示井间注采动态又显不足。重力测井具有探测范围大、受井径变化影响小、重复观测周期短、不受目的层埋深限制等优点。通过正演模拟分析表明,重力测井方法不仅可监测CO2前缘空间位置的变化,而且可以判定CO 相似文献