圆柱周围湍流场的数值模拟

In practical problems, the variation of the free surface around a circular pier is severe. For the Fluent CFD, the multiphase flow models cannot be used together with the LES model to calculate the free surface. Present paper provides a two-step method which joints the 2D compressible ideal-gas equations and the LES model to calculate the 3D flow field with free surface around the pier. The effects of the free surface on the flow structures are studied in detail.     

管壳式换热器流场数值模拟方法

介绍了对管壳式换热器研究的基本方法。对数值模拟的优缺点和模拟的软件做了简要介绍，并对常用于管壳式换热器的两种方法：直接数值模拟和多孔介质模型两种类别作了明确阐述。     

Simulation investigation on fluid characteristics of jet pipe water hydraulic servo valve based on CFD

Simulation investigation on fluid characteristics of the water hydraulic jet pipe servo valve (WHJPSV) is conducted through a commercial computational fluid dynamics (CFD) software package FLUENT. In particular, the factors to fluid characteristics of WHJPSV are addressed, which include diameter combination of jet pipe and receiver pipe, jet pipe nozzle clearance, angle between two jet receiver pipes and deflection angle of the jet pipe. It is concluded from the results that: (i) Structural parameters have ...     

Evaluating the effect of midpalatal corticotomy-assisted rapid maxillary expansion on the upper airway in young adults using computational fluid dynamics

Midpalatal corticotomy-assisted rapid maxillary expansion(MCRME)is a minimally invasive treatment of maxillary transverse deficiency(MTD)in young adults.However,the effect of MCRME on respiratory function still needs to be determined.In this study,we evaluated the changes in maxillary morphology and the upper airway following MCRME using computational fluid dynamics(CFD).Twenty patients with MTD(8 males,12 females;mean age 20.55 years)had cone-beam computed tomography(CBCT)images taken before and after MCRME.The CBCT data were used to construct a threedimensional(3 D)upper airway model.The upper airway flow characteristics were simulated using CFD,and measurements were made based on the CBCT images and CFD.The results showed that the widths of the palatal bone and nasal cavity,and the intermolar width were increased significantly after MCRME.The volume of the nasal cavity and nasopharynx increased significantly,while there were no obvious changes in the volumes of the oropharynx and hypopharynx.CFD simulation of the upper airway showed that the pressure drop and maximum velocity of the upper airway decreased significantly after treatment.Our results suggest that in these young adults with MTD,increasing the maxillary width,upper airway volume,and quantity of airflow by MCRME substantially improved upper airway ventilation.     

基于Pro/E模型导入ANSYS的方法

研究了Pro/E与ANSYS之间模型转换的几种方法,并以7500t浮式起重机人字架结构为例,对各种方法进行对比和探讨,得出使大型Pro/E模型顺利导入ANSYS的最优方法,为进一步有限元分析做准备。     

高超声速复杂流动中湍流模式的研究

研究了标准k-ε模式,双尺度湍流模式,并对其在壁面附近作出长度尺度修正在此基础上,选择了几个基准流动 :二维可压缩拐角、锥柱裙组合体绕流和斜激波⁄平板湍流边界层干扰,进行数值计算。通过数值计算和实验结果的比较,发现修正湍流模式对流动分离、摩阻和热流的计算具有更好的效果。     

数值模拟在某毒物泄露事故救援预案制定中的应用

随着我国经济的飞速发展和改革开放的不断深入,化工行业亦高速发展起来。由于种种原因,各类危化品泄露、火灾爆炸事故时有发生。科学、有效的制定应急救援预案并实施演练是消防部队快速反应、最大程度减少灾害事故危害的有效措施。探索和形成新的救援预案中灾情假定的方法对于掌握灭火作战行动的主动权与实现灭火指挥现代化具有极为重要的现实意义。利用计算机数值模拟对事故灾害行为进行分析,评价或预测灾害的行为效果,有利于根据现有消防力量合理调配,达到一次性调集、成功处置的目的。本文正是针对这一现实要求,利用数值模拟分析方法对某化工厂氨泄漏救援预案灾情设定进行研究。     

节能温室中的泡沫保温及自然通风研究

将绝热性能良好的透明流动泡沫填充于节能温室的外层覆膜空腔内,降低温室与外界环境之间进行热交换产生的能量损失或聚热,是一项温室节能新技术。借助流体动力学数字模拟计算程序（CFD）,对影响节能温室隔热性能的因素、通风窗结构进行了系统的优化研究,预测节能温室在冬季寒冷条件下的隔热性能和在夏季炎热环境下的通风降温效率,为节能温室设计提供依据。     

北京市传统大学生宿舍室内空气环境的模拟

本文旨在通过流场分布来研究北京市传统学生宿舍里的室内空气环境(包括室内压力场与速度场的分布情况)。文中采用k-ε双方程湍流模型来模拟空气介质，应用计算流体力学(CFD)的方法来求解室内空气流动，运用有限体积法来处理控制方程，并用Fluent模拟流场分布结果。分析结果表明，学生床上的通风情况跟床的位置有很大的关系。     

天津地铁站气流组织的数学模拟

为天津地铁改建、扩建所需 ,采用数学模拟方法对原有站台通风系统的气流组织效果进行评价 ,在此基础上提出通风系统的改建方案 ,并对新方案的速度场、温度场进行优化 .借助实际流场的测试数据判断紊流模型的适用性 ,并通过现场测试获得了所需边界条件值 .模拟结果与实测数据相符 ,证明了双方程紊流模型用于模拟站台的复杂流场是可行的 .模拟时将列车进站过程的瞬时流简化为稳定流 ,并对此假设前提下模拟结果的有效性给予认证 .