共查询到20条相似文献,搜索用时 93 毫秒
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通过测量EAST装置水冷系统的出入口冷却水的温差和流量,搭建了第一壁热负荷测量系统,实现了第一壁热负荷的分布测量。实验结果表明,在上单零偏滤器位形放电实验中,该系统测量的热负荷约占总注入能量的80%,其中,接近50%的热负荷沉积在上偏滤器区域。高的加热功率会使得第一壁热负荷更快上升。通过冷却水降温曲线拟合计算得出EAST装置上钨偏滤器水冷系统的热衰减时间约为下石墨偏滤器水冷系统的十分之一。 相似文献
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通过分析热波传输过程中产生的谐波的振幅谱和相位谱,测量了存在热耗散情况铜棒的热导率.该方法可以简化实验装置,消除谐波引起的系统误差,实验中热对流和热辐射对测量结果的影响可以忽略. 相似文献
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提高了一种采用方波热脉冲测量低温下固体结构材料的比热和热导率的非稳态方法。选用玻璃钢作为实验试样,所测量度范围为77-150K。通过一简单的方波热脉冲可直接测得试样的比热,由温升动态曲线可计算出试样的热导率,中给出了求解热导率的数学方法。 相似文献
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实验研究燕尾形轴向槽道热管启动/关闭及负荷变化的瞬态响应特性。建立了燕尾形轴向槽道热管的热阻理论预测模型,分析工作温度和热负荷及对热管总热阻的影响。结果表明:热管在负荷突然增加或减小时,响应特性良好;热管在启动过程中,热管的蒸发段、绝热段和冷凝段的温度都在增大;总热阻随热负荷的增大而增大;然而,总热阻受工作温度的影响较小;比较总热阻和平均温差的实验测量和计算值,两者符合较好。 相似文献
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文中以强化低温固体界面间的接触导热为出发点 ,实验测定了低温环境下两种金属界面在过度加载前后的接触热导值 ,指出过度加载是一种经济有效的强化导热方法 ,对卸载过程接触热导率大于同次加载过程接触热导的“hysteresis”现象产生机理进行了分析 相似文献
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In this Letter, a fractal series-parallel model, which included numerous capillary channels both parallel and perpendicular to the heat flow direction, was established to predict the effective thermal conductivity of fibrous porous material (FPM). The prediction results from the proposed model are compared with calculated values from other theoretical models and experimental data. 相似文献
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The thermal stress effects of the diode-end-pumped Nd:YLF slab laser crystals are numerically investigated. The theoretical model is established by considering the divergence of the pump beam in the slab and the additional heat generated in the upconversion. Using the three dimensional finite element analyses, accurate numerical solutions based on the theoretical model are achieved. Our analyses focuses on the thermal fracture damage of the Nd:YLF slab under both the lasing and non-lasing conditions, and the predicted values are compared with the experimental results. 相似文献
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建立了激光二极管阵列端面抽运棒状激光介质的数值模型.考虑到介质与空气的对流换热和介质的热力学参量随温度的变化,根据经典热传导方程和热弹性方程,运用有限单元法,得出了棒状介质内瞬态温度、热应力和应变的分布.分析了热透镜焦距随抽运功率的变化规律,所得的规律与有关文献相符合.理论分析结果可为激光二极管阵列抽运固体激光器的结构优化设计和实验提供理论参考. 相似文献
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The paper presents frequency modulated thermal wave imaging (FMTWI) as a fast and efficient non-contact technique for in-plane thermal characterization of thin plate nanomaterials. A novel excitation signal in the form of an up-chirp is applied and the thermal response is monitored using an infrared (IR) thermography based temperature sensing system. The in-plane thermal diffusivity of any sample can be measured using the multiple phase information extracted from a single run of the experiment. This feature provides a time efficient approach for thermal measurements using infrared thermography techniques. The theoretical background and experimental details of the technique are discussed, with practical measurement of thermal diffusivity of an empty anodic alumina (AAO) template in direction perpendicular to the nanochannel axis, in support. 相似文献
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The thermal effects of the diode end-pumped Nd:YVO4 slab laser crystal are investigated both analytically and numerically. The theoretical model is established with considering the divergence of the pump beam in the slab. A detailed theoretical analysis of the temperature, stress and the focal length of thermal lens are presented. Using 3D finite element analysis, an accurate numerical solution based on the theoretical model is achieved. Our analysis includes the thermal fracture damage of the thermally and optically anisotropic slab and the predicated values are compared with the experimental results. 相似文献
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EAST超导托卡马克冷屏结构与受力分析 总被引:3,自引:2,他引:1
EAST是一个全超导磁体系统的托卡马克实验装置,超导纵场和极向场磁体工作在4K温区下。在磁体和其它发热部件之间布置有冷屏系统,以减少作用到所有低温冷质部件上的热载,将其保持在最低水平。该系统包括真空室冷屏(内冷屏)和外真空杜瓦冷屏(外冷屏)两部分。在分析了冷屏低温运行时所受热应力以及等离子体破裂时所受电磁载荷的基础上,运用大型有限元分析程序NASTRAN,对其不同载荷状况进行了数值计算,为其结构设计与优化提供了理论依据。 相似文献
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Luis-David Patio-Lopez M. Amine Salhi Stefan Dilhaire Stphane Grauby Jean-Michel Rampnoux Sbastien Jorez Wilfrid Claeys 《Superlattices and Microstructures》2004,35(3-6):375
We propose in this paper an in-depth study of a method, both experimental and theoretical, for the determination of thermoelectric properties, in single, or multi-layered thermoelectric devices. We use a modulated laser beam as a heater in order to generate a thermally induced Seebeck EMF. The laser beam, line shaped, can be focused at any location along the sample surface, allowing spatially resolved measurements. Seebeck EMF measurements, associated with a versatile modeling method based on the thermal quadrupoles, allow determining sample Seebeck EMF profile. We contemplate to apply this technique to thermal and thermoelectric properties identification. 相似文献