家用空调冷凝器的仿真与实验研究

为了缩短对家用空调冷凝器的性能研究时间和开发新产品的周期,开发了冷凝器仿真程序。利用分布参数模型对家用空调冷凝器进行仿真计算,并设计建立了冷凝器实验装置,对仿真结果进行实验验证。对冷凝器进行了在不同风速,不同冷凝温度下的实验,进行分析得到实验结果。并将其与仿真程序的计算结果进行了比较。通过比较证明了仿真结果和实验结果总体变化趋势一致;在相同工况下,模拟换热量的数值比实验换热量要低7.7%~12%;由此验证了仿真程序的可行性。     

一种折反式光学系统的消杂光设计

针对一种折反式光学系统相机遇到的消杂光问题,根据杂光计算结果对相机进行了消杂光设计,通过试验对杂光计算结果进行了验证,试验结果与计算结果吻合,验证了消杂光设计的正确性。进行消杂光设计后,相机的杂光系数满足设计指标要求,有效地减小了杂光对图像质量的影响。     

变阻器的负载特性和调节灵敏度研究

对变阻器在分压、限流电路中的负载特性进行了讨论,并对其调节灵敏度进行了分析,给出了实验结果,表明理论分析与实验结果较好的符合。     

应用三维LDA对同向射流煤粉预燃室流场的研究

应用三维LDA对同向射流模型燃烧室的流场进行测量,对结果进行了分析。应用k-ε湍流模型进行了数值计算,计算结果与实验结果在定性上是一致的。     

耦合近场仿真及初步验模测试实验研究

针对电磁耦合仿真结果的校验需求,建立了基于光纤电场传感器的验模测试实验系统,对某模型的仿真结果进行了近场耦合验模测试。初步实验结果表明,在一定区域内,测试结果与仿真结果呈现趋势性一致,并对部分区域与仿真结果不符合的原因进行了分析,为下一步仿真模型优化和测试方法手段改进奠定了基础。     

炽热平板点火的计算研究

本文用数值计算的方法对炽热平板点火问题进行了研究,并将计算结果与实验结果加以比较,在层流流动中与实验结果的吻合令人满意,在湍流流动中也进行了计算,并对结果加以了讨论。     

空气横掠波纹管束流动与传热性能的数值模拟

本文应用层流模型和湍流模型的数值模拟方法,对空气外掠8排波纹管束时的流动与传热性能进行了研究,并将数值结果与实验结果进行了对比,结果表明:层流模型数值模拟结果较湍流更接近于实验值。同时,对两种模型的数值模拟结果拟合出了Nu-Re的关联式。     

喷动流化床的数值模拟研究

本文借鉴 Ｃｕｎｄａｌｌ＆ Ｓｔｒａｃｋ提出的碰撞模型,将欧拉方法和拉格朗日法结合起来,建立了喷动流化床气固两相流动的数学模型,在计算机上对试验台进行了模拟,探讨了床内颗粒的运动特征。按１：１的比例建立了喷动流化床的模型试验台并进行了试验,对模拟结果和试验结果进行了比较与分析。颗粒在喷动床内的运动特征,模拟结果都能够再现出来,模拟结果与试验结果取得了很好的一致性。     

“热线法”测定气体热导率数据处理方法及Origin软件应用的探究

在分析＂热线法＂测定气体热导率原理的基础上,以干燥空气为例对其热导率进行了测量,用＂线性外推法＂进行数据处理,并用Origin7.0软件对测量结果进行了数据分析,可快捷精确地获得测量结果。     

非接触圆筒形推拉式磁偶合联轴器的磁力矩公式的推理及其分析

本文对圆筒形推拉式磁偶合器的磁力矩 ,进行了推导 ,对推导结果进行了分析。     

光子晶体光纤在熔接夹具中的受力分析

运用接触力学和圆环压溃强度理论对由V型槽固定的光子晶体光纤进行了受力分析。分别考虑了两种极限情况,以推导光纤中的应力分布。第一种情况假设光纤是完全由纯石英材料制成的内部均匀的实芯圆柱体;第二种情况是把光纤假设成一个空芯圆柱体。根据这两种极限情况推导出了光子晶体光纤受力后光纤内部的最大应力点位于平行于接触面的外层空气孔的附近。采用有限元方法验证了此结论,计算出了光子晶体光纤可能承受的最大压力,并给出了光子晶体光纤在V型槽中的应力分布和变形情况。     

Two-dimensional convection; Oscillation of rolls with reversal of their sign of rotation

We consider a model of convection in which five hydrodynamic modes interact. We show the existence of oscillations in which the sign of rotation of the rolls is periodically reversed. When the Rayleigh number is increased, these oscillations exhibit a sequence of period doublings which is not of the Feigenbaum type.     

A General Theory of Non-Abelian Electrodynamics

The general theory of gauge fields is used to develop a theory of electrodynamics in which the fundamental structure is non-Abelian and in which the internal gauge field symmetry is O(3), based on the existence of circular polarization and the third Stokes parameter. The theory is used to provide an explanation for the Sagnac effect with platform at rest and in motion. The Sagnac formula is obtained by considering the platform in motion to be a gauge transformation. The topological phases can be described straightforwardly with non Abelian electrodynamics, which produces a novel magnetic field component for all types of radiation, a component which is proportional to the third Stokes parameter. The theory provides a natural explanation for the inverse Faraday effect without phenomenology.     

负载弦之演示教具

介绍一自制的负载弦教具，5颗沿铀向充磁的圆柱状钐钴磁铁穿在细钓鱼线上，作为负载弦之负载质点，再以可调频率的交流电磁化马蹄形电磁铁，使得马蹄形电磁铁对圆柱状钐钴磁铁施与周期性的引力及斥力，启动负载弦的各个简正模式．此自制的负载弦教具可定量演示教科书中理论计算的结果．     

Determination of the energy of electron in a quantum wire with a point defect

A problem of finding the energy of ground state of a quantum particle in a nanostructure with axial symmetry is considered. It is assumed that there is a point defect inside the nanostructure, which is given by δ-potential. A transcendent equation, which defines the lowest level of energy of the particle, is obtained. Corresponding formulas are used for calculation of the threshold frequency of interband absorption of light in semiconductor nanocrystals, which are dispersed in transparent dielectric matrix. Absorption spectrum edge dependence on location and power of δ-potential is obtained. It is shown that the effective length of the cylindrical nanocrystal is decreased in case of existence of δ-potential, which leads to increase in the threshold frequency of the optical spectrum of absorption.     

Classification of backscattering-enhancement mechanisms

A classification is provided for the principal backscattering-enhancement mechanisms, which are divided into singleparticle and collective mechanisms, which, in turn, consist of geometrical mechanisms and mechanisms associated with phase coherence. A distinction is made between dynamic mechanisms, which appear in nearly all realizations, and statistical mechanisms, which are observed only after averaging.     

On the stationary properties of an open system with internal coherent interactions

The asymptotic behaviour of an open system in which coherent and incoherent interactions interfere is discussed. It is shown that a stationary density operator exists which is diagonal with the coherent interaction, and that detailed balance is satisfied. A model-independent form for this density operator is given. A class of systems is identified for which the stationary solution can be constructed explicitly and in which some known models are contained.     

High-efficiency conversion of the electronic excitation energy to the translational degrees of freedom in collisions of excited atoms with the surface of a solid

An experimental study is reported about the quenching of electronic excitation of Cs atoms caused by their collisions with a glass surface. The energy with which they are scattered from the surface after quenching has been measured to be 0.5 eV, which is about one-third of the excitation energy. A discussion is given of the mechanisms by which the excitation energy is partitioned between the atom and the surface in two different cases, namely, in the excitation of the atom adsorbed on the surface and in the collision of the preexcited atom with the surface.     

非稳腔模式计算中Colins公式适用性的分析

Ｃｏｌｉｎｓ公式将几何光学和波动光学联系在一起，能以简单的形式描述相干光在复杂光学系统中的传输，但忽略了光学系统中一些光学元件的衍射损耗。当Ｃｏｌｉｎｓ公式用于激光谐振腔的本征模式计算时，其适用程度与被忽略腔镜的有效菲涅尔数有关。本文用数值方法求解了两组谐振腔本征积分方程，一组应用Ｃｏｌｉｎｓ公司推导，另一组用菲涅尔－惠更斯衍射积分推导，结果表明：对稳定腔Ｃｏｌｉｎｓ公式基本适用；对非稳腔，当被忽略腔镜的有效菲涅尔数＞１时，原则上可以用，当被忽略腔镜的有效菲涅尔数＜１时不适用；对有源非稳腔基本适用。