查询词典 convection heat transfer

Furthermore the performances of heat transfers including corrugate plate, tube and fin-tube were compared under the same conditions. The results show that when the air frontal velocity is between 2.45 and 4.1m/s, the overall heat-transfer coefficient of plate heat exchanger ranges from 100 to 160 W/m^2/ equal to one sixth of that of fin- tube cooler based on tube outside area, which is about 70% higher than that of tube cooler. The volumetric heat transfer capacity of plate cooler is 1.5 times as that of fin-tube cooler and 15 times as that of tube cooler. The heat transfer capacity of per unit power of plate cooler is 5.5 times as that of tube cooler and similar results for fin-tube cooler.

在相同工况下，比较了波纹板式、光管式和翅片管式空冷器的性能指标，结果表明：迎面风速在2.45~4.1m/s之间，波纹板式空冷器传热系数达到100~160W/平方公尺/℃；约比光管式提高70%，但只有以管束外表面为基准的翅片管式传热系数的六分之一；板式空冷器单位体积换热量约是翅片管式空冷器的1.5倍，是光管式的15倍；板式空冷器单位功耗换热量约是光管式空冷器的5.5倍，而翅片管式空冷器与光管式空冷器则相差不大。

And, theoretical and experimental studies have been carried out of the performance of the heat transfer enhancement by adding a proper amount of nanoparticles to the thermosiphon with water as the working fluid. Compared with the ordinary thermosiphon, results indicate that this heat pipes posses such advantages as good startup, lower tube wall temperature, and its heat transfer coefficient is increased by 47～96%, heat flux is increased by 7.6～15% in the range of the experiment. The performance of the heat transfer relates to the diameter and the volume fraction of nanoparticle.

理论和实验的研究了这种热虹吸管蒸发段的工作特性，结果表明，与普通热管相比较，这种新式热管具有很好的启动特性，低的管壁温度，换热系数提高了47～96％，轴相热流率提高了7.6～15％，其换热性能随纳米颗粒粒径的减小而增大，随纳米颗粒加入量有所增加，当超过一定量时换热性能反而降低了。

The modified model took into account not only the coupled heat transfer of conduction, convection and radiation, but also the heat convection between each zone caused by temperature difference and airflow.

该模型综合了墙体热传导、壁面对流热交换以及内部控制体之间的对流热交换过程。

The concrete work and main contribution are as follows:(1) The index indicating transfer capability homogeneousness is defined, and the new terms like homogeneous grid, grid according with economic flow are put forward. These new concepts describe the degree in which transfer capability is utilized, and they provide the standard for ideal grid whose transfer capability and power generation dispatching economy are in phase. So, new idea is introduced in transfer capability analysis.(2) The multi-objective function with generation cost and transfer capability homogeneousness weighted is constructed. The relationship between system existing generation dispatching and transfer capability is revealed through comparative analysis between security economic dispatch and security homogeneous dispatch, and the variation rule analysis between generation cost and transfer capability homogeneousness with the change of weighting coefficient.(3) Example analyses demonstrate that the difference between specific power system with ideal instance can be identified effectively using the above concepts and method.

具体工作和贡献主要体现在：(1)定义了衡量电网输电能力均匀性分布的指标，提出均匀电网、符合经济流电网的新概念，以描述电网输电能力被利用的程度，并给出输电能力和发电调度经济性相协调的理想电网标准，在输电能力分析评判领域引入了新观点；(2)构造了发电费用与输电均匀性加权的多目标函数，通过对安全经济调度与安全均匀调度的对比分析，以及权系数变化过程中发电费用与输电均匀性的变化规律分析，揭示了系统现存发电调度与输电能力之间的依赖关系；(3)大量分析表明，利用上述概念和方法可有效识别系统在特定模式下与符合经济流电网的偏差程度。

The system of shareholders withdrawal will be designed as two ways: one is the general transfer that is implemented through the agreement between the shareholder and other people, including the internal transfer and external transfer; the other is the compulsory transfer that means other ways except the general transfer, including the appraisal right of dissenters in the limited liability company, the transfer on specific facts (as inheritance、division of property between husband an wife、impawn) and the transfer on the compulsory implementing of court.

本文将有限责任公司股东退出机制设计为两种方式，其一，普通转让，即股权的转让是股东与他方以协议的方式实现的，包括股权的对内转让和对外转让；其二，强制转让，指的是除通过协议转让的其他转让方式，包括异议股东股权回购、因特定事实的发生而因其的股权转让(包括因继承、夫妻财产分割、质押等引起的股权转让)以及因法院强制执行而引起的股权转让。

The invention comprises a main body of the reactor, the dynamic heat pipe, fins, a turbine, a motor, a transmission mechanism and a cold air jacket; the segment of the dynamic heat pipe in the main body of the reactor is a heat absorbing section; the segment of the dynamic heat pipe outside the main body of the reactor is a heat release section; the main technology characteristics are that the heat absorbing section of the dynamic heat pipe is connected with a central stirring shaft; and the heat absorbing section is used as a mixing impeller blade.

本发明包括反应器主体、动态热管、肋片、涡轮、电机及传动机构、冷风夹套，动态热管在反应器主体内的一段为吸热段，在反应器主体外的一段为放热段，其主要技术特征在于动态热管的吸热段与中心搅拌轴连接，吸热段作为搅拌桨叶。

The special material is adopted to enhance the radiation and heat conduction heat transfer, and the cellular strengthener whose surface area is bigger can enhance the convection heat transfer.

其采用高导热非金属材料为主体材质达到增强导热及辐射的目的；通过采用蜂窝体形式达到增大比表面积，从而增强对流换热的目的。

A wall heat flux function was introduced to separate the numerical prediction of internal heat transfer in aircraft from that of thermal effects outside the skin.The thermal network method combined with the Monte Carlo method was used to analyze the internal heat transfer and the FLUENT code was employed to simulate the aerodynamic convection outside skin.

引入壁面热流函数，将蒙皮外部热环境与飞机内部换热进行解耦计算，采用热网络法与蒙特卡罗法进行飞机内部传热分析，利用FLUENT软件进行蒙皮外气动对流换热模拟，建立了飞机蒙皮瞬态温度场的数值方法。

Based on the thermodynamic analysis of heat transfer process between water jet and the blade surface, the differential equations of heat convection and differential equation of steady heat conduction between water jet and the blade surface are established. Power expression of heat exchange and temperature field expression of the blade are derived.

根据对水射流与刀片间传热过程的热力学分析分别建立了水射流与刀片表面对流换热微分方程组和热源与刀片间的稳态导热微分方程，推导出水射流对刀片的换热功率表达式和刀片内温度场表达式。

In the analysis, firstly, the flux boundary condition is used to simulate the frictional heat resource between wheel and rail. The non-steady heat transfer between the contacting surfaces of the wheel/rail, heat-convection and radiation between the wheel/rail and the ambient were all taken into consideration. Therefore, a heat coupling model of the wheel/rail in rolling/sliding is put forward to calculate the frictional temperature rise in the wheel and rail. Secondly, after the temperature distribution of wheel/rail, due to friction, is calculated, substitute the thermal load with equivalent fictitious body force and boundary distributed force loaded on the nodes of the corresponding elements. The wheel-load is applied to the center of the wheel.

首先，用热流边界条件模拟轮轨接触界面的摩擦热源，考虑轮轨间的非稳态热传导、轮轨自由表面与环境的热对流、热辐射的影响，建立轮轨滚动接触热耦合有限元计算模型，分析计算轮轨滚、滑工况下的摩擦温升；其次，以求得的轮轨温度场结果作为求解轮轨应力场的已知条件，轮载以集中力形式直接加载于轮心处，将摩擦温升引起的热载荷等效为假想体力和热边界面力，施加于相应的单元节点上，建立了轮轨热—机械载荷耦合作用的热弹性平面应力模型，分析热—机械载荷作用下的轮轨应力场。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48