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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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一、前言 回收工业低温(t<150℃)余热发电或作其它动力,能收到良好的节能效果。一般采用低沸点工质,用向心透平作膨胀机较为合宜。向心透平设计中,大多沿用轴流透平的叶栅资料,经保角变换而得.向心环形叶栅资料很少,有待进一步开拓。本文用时间相关法编程对向心环形叶栅作流场计算,用附面层原理计算叶栅叶型损失,并作了二套叶栅的吹风试验,结果符合较好,提供了向心环形叶栅的一种计算方法。 相似文献
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本文提出了一种经验调整分区变分能带计算方法。它通过球外势的调整来使算得的能带更接近于实验结果。应用这一方法计算了锗和硅的能带。所得结果和实验值吻合得很好。针对在不同势场区域内用不同方法计算的特点,我们又提出了计算合金固溶体能带的新模型。运用同样的调整参数来计算锗硅合金的能带,获得了比OPW法更好的结果,从而说明这是一种有效的能带计算方法,可望在其它领域中获得更多的应用。
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A molecular-dynamics scheme in the embedded-atom method is shown to be the efficient and accurate in studying liquid aluminium system. The ability of the method in studying liquid system is demonstrated by calculating the intent heat, self-diffusion coefficient, pair distribution function of aluminium, and so on. All of the results agree well with experimental results. The background electron density is also calculated using this method, and the result shows that a discontinuous change occurs at melting point for the electron density in the system. 相似文献
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Nonlinear optical properties in double-sided nonlinear media with Z-scan technique based on the Huygens——Fresnel principle
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We present a theoretical model to analyse the propagation of a Gaussian laser beam
through double-sided nonlinear media. This model is based on the Huygens--Fresnel
diffraction integral method. This theoretical model is not only consistent
with the cascade structure model for a small nonlinear phase-shift but also can be
used for a large nonlinear phase-shift. It has been verified that it is suitable to
characterize the double-sided nonlinear media compared with the cascade structure
model. A good agreement between the experimental data and the results from the
theoretical model is obtained. It will be useful for the design of multi-sided
nonlinear materials. 相似文献
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推算乙烷系氟里昂饱和液体粘度的基因贡献法吕萍,刘志刚(西安交通大学能动学院西安710049)关键词基团贡献,粘度,乙烷系氟里昂1引言CFCS物质很快将被禁用,寻找合适的替代物已成为当务之急。在CFCS替代物的研究中粘度是必不可少的迁移性质之一。CFC... 相似文献
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采用曲线拟合方法进行EPR波谱基线校正 总被引:1,自引:0,他引:1
提供了一种以曲线拟合方式进行的EPR波谱基线校正的简单方法.程序置于486微机上,采用C++语言编写,在Windws环境下运行.使用菜单、模块化方式.操作简单,快捷.在联机进行数据采集时尤为方便.本程序对需要进行基线校正的谱线,只需使用鼠标器在实验谱上选择一定的数据点,通过程序运算,比较,验算即可得到较好的基线校正. 相似文献
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Experimental determination of cascade parameters of a hearing-aid microphone via the two-load method
D P Egolf B T Haley K M Bauer H C Howell V D Larson 《The Journal of the Acoustical Society of America》1988,83(6):2439-2446
Presented in this article is a computer-aided experimental method for obtaining the cascade parameters of the two-port model of a miniature hearing-aid microphone. The method is an adaptation of the "two-load" method [D.P. Egolf and R.G. Leonard, J. Acoust. Soc. Am. 62, 1013-1023 (1977)] to acoustoelectric, rather than electroacoustic, transducers. The cascade parameters of a particular microphone, determined by this method, were within 2.5 dB of the manufacturer's published open-circuit sensitivity data. In an attempt to further verify the numerical cascade-parameter data, a two-port model of the microphone was used to simulate experimental voltages developed across two different complex electrical load impedances attached to the microphone. The results showed experimental/simulation differences of no greater than 3.0 dB at any frequency. The two-port microphone model and associated cascade parameters are currently being incorporated into a computer-based plan for mathematical simulation of an entire in situ hearing aid. 相似文献