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121.
In the present paper the elastostatic problem of a generally anisotropic and angularly inhomogeneous plane wedge loaded at its apex by a concentrated force, is studied in linear elasticity. At first the self-similarity property is formulated and the stress field of the inhomogeneous anisotropic self-similar wedge problem, is deduced. The wedge is radially separated and the plane wedge problem is reformulated by the introduction of a characteristic vector. Furthermore, the angular distribution of the load is determined. The multi-material wedge problem in terms of a formulation based on the isotropic angularly inhomogeneous wedge, is confronted, and necessary conditions that ensure the self-similarity property, are found. Finally, the similar elastostatic wedge problems and the involution between stresses, are studied.
Mathematics Subject Classifications (2000) 74B05, 74K30, 34B05, 51N15. 相似文献
122.
The aerodynamic characteristics and distinctive features of the flow past hypersonic integral-layout flight vehicles with air-breathing engines intended for cruise flight in the atmosphere are experimentally investigated. The experiments were conducted on a simplified model designed with regard for the general principles of integration of vehicles of the class considered. The tests were performed in a wind tunnel over the Mach and Reynolds number ranges 0.6 ≤ M ≤ 4 and 6.3 × 106 ≤ Re ≤ 16 × 106, respectively. Balance testing was carried out, the pressure distributions over the vehicle surface were measured, and the flowfields on the model surface were photographed. The effects of mounting a nacelle and contouring the internal duct are considered. The effect of the corrections on the duct flow in the absence of jet modeling is estimated. The results obtained can be used as a basis for developing the aerodynamic configurations of integral-layout flight vehicles, for forming their thrust and aerodynamic parameters under full-scale flight conditions, and for testing computation methods. 相似文献
123.
为研究小口径喷嘴冲击射流的噪声特性,测定了3mm口径的轴对称收缩喷嘴在各种压比情况下产生的亚音速和超音速射流冲击坚固大平板产生的噪声。发现噪声在空间呈近似四瓣分布,当喷嘴与平板距离减小时,噪声指向壁射流下游的瓣到增强,反之,噪声指向喷嘴上游的瓣得到增强。噪声随喷嘴距平板距离的增加呈增强的趋势,在距平板一定距离内有锯齿现象。噪声随喷嘴压比的增加而增强,相应于各种工况,存在一不同的压比值,此压比之前,噪声随压比的增大而迅速提高,但有起伏现象,在此压比之后,噪声平缓地随压比的增大而增强。 相似文献
124.
The antiplane analysis is made for a bimaterial BaTiO3–CoFe2O4 composite wedge containing an interface crack. The coupled magneto-electro-elastic field is induced by the piezoelectric/piezomagnetic BaTiO3–CoFe2O4 composite materials. For the crack problems, the intensity factors of stress, strain, electric displacement, electric field, magnetic induction and magnetic field at crack tips are derived analytically. Also, the energy density criterion is applied to predict the fracture behavior of the interface crack. The numerical results also show that the energy release rate for a crack in a single wedge is negative. 相似文献
125.
The flow in a convergent nozzle equipped with chevrons and the flow around the chevrons are numerically simulated and studied on the basis of the numerical integration of the system of Reynolds equations closed by a differential model for the turbulent viscosity. From the calculated results, the flow pattern, the action of the chevrons on the flow, the circulation generated, and the values of the parameters characterizing the streamwise vorticity are determined. The results of calculations of the thrust and flow-rate characteristics of nozzles equipped with chevrons are presented. The data for chevron and conical nozzles are compared.__________Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, 2005, pp. 76–88.Original Russian Text Copyright © 2005 by Brailko and Krasheninnikov. 相似文献
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