共查询到19条相似文献,搜索用时 328 毫秒
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非正交曲线坐标下三维粘性流动数值分析 总被引:3,自引:2,他引:1
本文基于非正交曲线坐标与相应的非正交速度分量下导得的守恒型N—S方程,讨论了求解三维粘性流动的数值方法,计算中显式时间推进算法与Baldwin—Lomax湍流模型被采用,应用本工作发展的程序,作为算例计算了一个沿径向非等截面环形叶栅的三维粘性流场,得到了诸如三维压力分布,总压损失分布以及十分清晰的二次流动图景等丰富的流场信息。 相似文献
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涡轮叶栅二次流损失的实验研究 总被引:2,自引:0,他引:2
为了研究涡轮叶栅内部二次流的流型及损失,在平面叶栅风洞上对叶栅流道内部及出口平面上用微型四孔测针进行了详尽的测量,配之以叶型和端壁表面的静压实测值及二维等熵流场计算,得到了二次流的流型。作者还根据多次试验结果,拟出了二次损失的物理模型和预估方法。 相似文献
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非绝热壁叶栅的粘性流动王正明(中国科学院工程热物理研究所北京100080)关键词非绝热壁;叶栅;粘性流动1引言近年来,随着计算机运算速度的提高,叶轮机械内部粘性流动的数值解法发展很快,对于动量方程,已广泛采用亘接求解不作简化的完全的N-S方程,以便更... 相似文献
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叶顶间隙对环形叶栅三维粘性流场影响的数值分析 总被引:1,自引:0,他引:1
1前言考虑叶顶间隙影响的三维叶栅粘性流场特性的数值模拟是当今比较流行的研究课题。顶部泄漏流动的研究对更准确分析、设计三维叶栅具有重要意义。近年来,国内外的学者使用了多种不同的数值方法及实验方法对叶顶间隙流进行研究。然而,以往的计算往往局限于直列叶栅,... 相似文献
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Quantum mechanics forbids deterministic discrimination among nonorthogonal states. Nonetheless, the capability to distinguish nonorthogonal states unambiguously is an important primitive in quantum information processing. In this work, we experimentally implement generalized measurements in an optical system and demonstrate the first optimal unambiguous discrimination between three nonorthogonal states, with a success rate of 55%, to be compared with the 25% maximum achievable using projective measurements. Furthermore, we present the first realization of unambiguous discrimination between a pure state and a nonorthogonal mixed state. 相似文献
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We calculate the magnetic properties of small FeN clusters(N=2~7,9,13,15) by using a parameterized Hubbard tight-binding sp d-band model Hamiltonian, with the parameters obtained from nonorthogonal Ham il tonian parameters. the average magnetic moments, and the spin-polarized charge distribution within clusters are in agreement with those obtained by first-prin ciple and tight-binding calculations. The effect of the nonorthogonal basis is discussed. 相似文献
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M. Pugaczowa-Michalska 《Solid State Communications》2006,140(5):251-255
A computational study of the pressure and thermal behaviour of NiMnSb within the framework of density functional theory and the Debye-Grüneisen model is reported. The theoretical values of equilibrium lattice parameter, bulk modulus, its pressure derivative, Debye temperature, Grüneisen constant and coefficient of thermal expansion are estimated from electronic structure calculated by the full-potential nonorthogonal local-orbital minimum basis method (FPLO). The bulk modulus and its pressure derivative have been computed using the Murnaghan form of the equation of states. The volume-temperature dependence was obtained by minimisation of the free energy as a sum of the total energy of the rigid lattice and the free energy of the vibration lattice. The thermal expansion coefficient for the studied NiMnSb, obtained within the Debye theory including anharmonicity, is in good agreement with experimental results. 相似文献
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A quantum key distribution protocol with nonorthogonal basis states is a generalization of the known BB84 key distribution protocol. The critical error and length of a secure key have been determined for the protocol with nonorthogonal basis states for an arbitrary angle between information states. An explicit optimal attack on the distributed key has been constructed; this attack maximizes eavesdropper information at a given error on the receiver side. 相似文献
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Baye D Vincke M 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,59(6):7195-7199
The Lagrange-mesh numerical method has the simplicity of a mesh calculation and the accuracy of a variational calculation. A flexible general procedure for deriving an infinity of new Lagrange meshes related to orthogonal or nonorthogonal bases is introduced by using nonclassical orthogonal polynomials. As an application, different Lagrange meshes based on shifted Gaussian functions are constructed. A simple quantum-mechanical example shows that the Lagrange-mesh method may become more accurate than the original variational calculation with a nonorthogonal basis. 相似文献
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In this paper, we consider the minimax strategy to unambiguously discriminate two pure nonorthogonal quantum states without knowing a priori probability. By exploiting the positive-operator valued measure, we derive the upper bound of the minimax measurement of the optimal unambiguous state discrimination. Based on the linear optical devices, we propose an experimentally feasible scheme to implement a minimax measure of a general pair of two nonorthogonal quantum states. 相似文献