微型汽车空调除霜除雾风道的技术改进

汽车空调的除霜除雾性能对汽车安全驾驶非常重要,国家相关法规只对前挡风玻璃上的除霜除雾有要求,而对前门侧窗上的除霜除雾尚无要求.为了解决困扰用户的某款微型汽车前门两侧窗玻璃除霜除雾的问题,对除霜除雾风道作了技术改进,并进行了经验总结.     

浅析汽车空调除霜风道设计

除霜（及除雾）是空调系统三大功能之一，功能缺失可能影响车辆行驶安全性。除霜系统由两部分组成，即除霜风道和空调系统。重点研究除霜风道设计，既有基本的结构设计要求，同时提出前挡风玻璃风速分布要求，并利用CFD仿真分析及整车除霜试验方法进行验证。     

某轿车前挡风玻璃除霜模型建立及性能仿真研究

针对新上市的某车型,根据霜的形成原理,建立该车除霜系统物理模型和数学模型,利用CFD软件成功模拟了该车前挡风玻璃的稳态速度流场,以及除霜瞬态过程中的物理现象。分析发现该车型前挡风玻璃除霜系统压力损失大,风道各出口流量比例不合理,存在速度死区。提出了改进的建议,仿真模拟表明,新方案更加融霜的气流分布更加的均匀。     

乘用车除霜除雾效果分析

根据既有数据,利用HyperMesh和Fluent等软件对一款乘用车的前挡风玻璃和左右侧窗玻璃进行除霜除雾分析,检查该款车辆的除霜除雾时间能否满足相关标准的要求.     

汽车前挡玻璃除霜性能研究

利用STAR CCM＋软件,在既定的空调进风口位置、出入口边界条件对汽车内部气体流动过程进行了模拟,得出了某车型前挡玻璃除霜性能的分析结果。为汽车除霜空调设计及优化的工程应用提供依据。     

某车型前挡风玻璃除霜除雾性能优化设计

针对某车型前挡风玻璃除霜除雾性能问题,通过CFD仿真计算分析发现其风量分配与出风口风速满足目标要求,但A柱附近玻璃局部区域壁面风速偏小。因此,在风道上设计两种辅助出风口方案,对局部区域进行风速与温度提升。经过CFD分析与试验测试对比,优选一种方案,可以有效解决前挡风玻璃除霜除雾性能问题。     

景逸汽车除霜系统的CFD优化设计

利用CFD软件对景逸汽车空调除霜性能进行了分析,并根据分析结果,对除霜风道进行了修改,最终满足了设计要求.     

汽车前风窗玻璃的除霜性能数值研究

基于RNGk-ε湍流模型,对汽车前风窗玻璃的除霜性能进行研究。建立B柱前乘员舱模型和完整乘员舱模型,研究计算域对除霜仿真结果的影响。为保证分析结果的准确性,模型中将驾乘人员及座椅包含在内,且在仿真过程中考虑人体热源的影响。数值分析结果表明,完整乘员舱模型的计算收敛时间比B柱前乘员舱模型增加44%,而两种模型的出风口风量分配和前风窗稳态风速相差很小。两种模型的前风窗平均温度、霜层液态分数差距比较明显,完整乘员舱模型的瞬时除霜结果与实验值能较好吻合,且能准确反映驾驶员呼吸点的温度。因此,当以除霜风道的风量分配为分析目标时可采用B柱前乘员舱模型,但在研究瞬时除霜效果、评价除霜工况下的车内热环境时,必须采用完整乘员舱模型进行分析。     

基于SST k-ω模型的汽车空调CFD仿真分析

以汽车空调为研究目标,利用SST k-ω两方程模型,在除霜模式下分别对带HVAC及不带HVAC的空调系统进行仿真计算,分析了HVAC系统对仿真计算结果产生的影响。此外,分析结果显示位于驾驶员侧的前挡玻璃表面速度满足要求,位于副驾驶侧的前挡风玻璃表面速度大于1.5 m/s的区域覆盖率仅为75%左右,不满足国标要求。侧窗玻璃表面速度均值不到1 m/s,也不满足国标,仿真结果与试验结果对比相一致。风道存在较大问题,导致除霜风道气体集中从中间风道吹出,两侧风道的气流极小。根据结果提出进一步的改进建议,即在除霜风道增加必要的隔板装置,为汽车空调的改进设计提供依据。     

除湿机除霜设计与实验研究

分析了除湿机的除霜方法,对除湿机进行了除霜设计和实验研究,结果表明时间温度控制除霜法是较为有效和实用的方法,它能根据室内温湿度对结霜霜层的影响进行除霜,在除湿机结霜温湿度范围内对除霜周期具有一定的自调性.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...