共查询到10条相似文献,搜索用时 62 毫秒
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Energy-saving roof renovation methods are effective ways to alleviate the urban heat island effect. In this paper, the authors propose three models of two-layer water-retained bricks, established the physical and mathematic models of the water-retained bricks, and then conducted a computational fluid dynamics (CFD) simulation on the effect of wind speed and evaporation space height on the water-evaporating performance of water-retained bricks. The results show that: (1) for the water-retained bricks with no-hole lids, macroscopic evaporation does not happen under the static wind conditions; with the increase of wind speed, the evaporating boundary layer thickness decreases, the water vapor concentration gradient in the boundary layer and the mass diffusion flux increase; (2) for the water-retained bricks with strip-hole lids, under the static wind condition, the evaporating performance of the water-retained bricks with strip-hole lids is better than that of bricks with no-hole lids; with the increase of wind speed, the evaporation of bricks with strip-hole lids is less affected by inlet airflow velocity than that of bricks with no-hole lids; (3) as for both the water-retained bricks with no-hole lids and with strip-hole lids, for a given wind speed, both the water vapor concentration gradient and the mass diffusion flux decrease as the evaporation space increases. 相似文献
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采用气动力/热/结构耦合的方法对高速细长体飞行器结构热静气动弹性问题进行了研究.为保证耦合计算精度,达到准确预测热气动弹性特性的能力,气动力和气动热计算采用CFD数值模拟方法,热应力和热变形计算采用有限元方法并通过热考核试验验证.以该简单细长体飞行器模型为研究对象,对其热静气动弹性特性进行了计算与分析,计算结果表明:CFD/CSD耦合可准确模拟热气弹问题,且气动加热造成结构温升不均衡是结构变形的主导因素,力热耦合静气弹变形与单纯受力分析变形形式不同,对飞行器气动特性影响规律不同.准确预测飞行器热气动弹性特性对飞行器结构设计十分必要. 相似文献
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Gaurav Kumar Bharti 《Fiber and Integrated Optics》2018,37(2):103-121
The present paper describes various attractive logical code conversions using optical micro-ring resonator. We have proposed an all-optical switching activity using silicon waveguide based micro-ring resonator under low-power operation through two-photon absorption effect. The different properties of the optical switch are analyzed through numerical simulation. We have also proposed and described all-optical binary-to-octal, binary-coded-decimal-to-excess-3 and binary-to-Gray-code converter circuits by this proposed architecture. Numerical simulation results for code conversion verifying the proposed methods are given in this paper. We identify a combination of feasible ring radius and detuning through numerical simulation that allows analyzing the system performance of the scheme. 相似文献
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通过对Willmore区域外,特别是中等及较小约化体积下的形状及其演化进行深入细致的研究,发现在这一区域的形状要远比原有的猜测丰富,亏格g=2的膜泡会展现出比已有结果更多迷人的形状并出现新的膜泡相变分支.同时,数值计算的结果更加期待实验验证,从而为曲率模型的正确性提供有力支持. 相似文献
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高精度瑞奇-康芒检测法研究及测试距离精度影响分析 总被引:1,自引:0,他引:1
为实现高精度瑞奇-康芒法检测,利用检测系统光瞳面与被测平面镜二者间的坐标转换关系,结合最小二乘法直接对测得的系统波像差进行恢复,通过两角度检测分离由光路调整引入的离焦误差,得到更为精准的平面镜面形。分析光路中测试距离对坐标转换关系以及瑞奇角求解精度的影响,根据仿真分析结果确定实验方案。实验中采用两角度检测,对测试波前进行恢复并分离系统调整误差后,最终得到被检平面镜面形,结果峰谷(PV)值为0.182λ、均方根(RMS)值为0.0101λ,对比干涉仪直接检测结果 PV值为0.229λ、RMS值为0.013λ,PV检测精度优于λ/20,RMS检测精度优于λ/100,实验结果证明了此种面形恢复方法的有效性以及测试距离精度分析理论的正确性,从而实现了瑞奇-康芒法高精度检测。 相似文献
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GUO Shuqin XIAO Yan XUE Wenrui LI Zhonghao ZHOU Guosheng Department of Physics Shanxi University Taiyuan China Department of Electronics Shanxi University Taiyuam China Received Aug. Re 《Chinese Journal of Lasers》2001,10(4):277
1 Introduction Despitethegreatsuccessofwavelengthdivisionmultiplexed (WDM )systemsinachievinghigh capacitytransmission ,thereremainsinterestinexploringthecapabilitiesofhighdatarateinsinglechannelsystems.Thepropagationofchirpedpulsesinopticalfibersisofgr… 相似文献