铁路空调客车车内气流组织的数值模拟

本文以铁路空调客车为研究对象．采用k-ε双方程模型,对客车室内的气流组织进行数值模拟,得到了有车内热负荷存在时的车内温度、速度场分布模拟计算结果。通过与试验结果的对比,对影响车内温度、速度场的因素进行了初步分析。     

内置式客车空调气流组织的数值模拟

本文介绍了内置式客车空调的气流组织，运用κ-ε模型进行了模拟，并与顶置式空调进行了对比。结果表明，内置空调的温度、速度分布较佳，车内的气流组织更合理。车内空气的温度、流速以及相对湿度等共同作用的效果更符合人的生理及心理需要。     

空调硬卧车内气流组织的数值模拟研究

空调车内气流组织研究是车厢内热环境控制的基础，合理的车内气流组织可有效地改善乘客的冷热舒适性。采用k-ε湍流模型对25K型空调硬卧车内气流组织进行了数值模拟，研究了不同送风方式和送风参数下车内空气流场和温度场分布规律，并与实验结果进行了对照，两者基本一致。研究结果对于改善硬卧车内人体冷热舒适性提供了理论依据，对车内气流组织优化设计有指导意义。     

空调客车车内空气品质控制系统的设计

客车空调注重满足人体热舒适的要求,对空气的清洁度重视不够,车内空气的污染物严重地影响乘员的健康。开发传感器准确、快速地测定空气的污染物,通过电子控制系统改善车内空气品质势在必行。介绍传感器的结构、原理及应用,并设计空调客车车内空气品质电子控制系统。     

中学教室空调气流组织的数值模拟研究

针对相同室内条件、不同送回风口位置下的两种模型,运用暖通空调专用数值模拟软件Airpark,对室内速度场、温度场进行了数值模拟计算。并根据模拟结果分析不同送回风口位置下的空气品质和人体热舒适,为教室等人员密集区域空调室内的气流组织形式优化设计提供了研究依据。     

湍流模型在列车空调气流组织中的应用

空调车室内空气的速度场,温度场研究是空调车室内气流组织设计及空调室内舒适环境评价与研究的基础.针对零方程模型,k-ε湍流模型,湍流大涡模型在列车空调气流组织中的应用进行分析比较,所得结论对列车的空调效果及车内舒适环境的优化提供了依据.     

基于 ADPI 的房间空调器气流组织性能评价

利用 Airpak 软件对某空调办公室的气流组织和热环境进行数值模拟,对该办公室速度场、温度场进行了分析研究,并按照 ISO7730标准,采用有效吹风感温度ΔET 和空气分布特性指标 ADPI 对室内气流组织性能进行评价,为空调室内气流组织形式的优化设计及热舒适性的改善提供了依据。     

微型客车车内气流速度场的三维数值模拟

采用UG建立微型客车车内结构的几何模型,运用ANSYSIECM10.0划分网格,以微型客车空调车内流动的空气气流为研究对象,应用标准K-ε湍流计算模型,通过Fluent软件分析前、顶蒸发器不同的送风角度车内的速度场的分布特征,为设计微型客车车内均匀气流场提供参考依据.     

空调羽毛球场馆内三维紊流流动的数值模拟与研究

体育场馆空调馆内气流的速度场、温度场的研究是体育场馆馆内气流组织设计及舒适环境评价与研究的基础.本文采用k-ε双方程模型对某大空间空调羽毛球场馆馆内三维紊流流动进行了数值模拟,利用有限容积法和SIMPLE算法对微分方程进行离散、求解,对模拟结果进行了分析与研究,为室内空调系统设计、方案优化提供了重要的参考资料.     

阅览室内空气品质及热舒适性的模拟分析

利用Fluent公司推出的Airpak软件,针对夏季工况下某大学图书馆阅览室内速度场、温度场进行了数值模拟计算,根据模拟结果对阅览室内空气品质、舒适度进行了分析,为空调房间的气流组织形式优化设计以及室内热环境的改善提供快捷,方便的解决方案。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.