Hall current effects on MHD flow of chemically reacting fluid through a porous medium with heat source

We considered the magnetohydrodynamic (MHD) free convective flow of an incompressible electrically conducting viscous fluid past an infinite vertical permeable porous plate with a uniform transverse magnetic field, heat source and chemical reaction in a rotating frame taking Hall current effects into account. The momentum equations for the fluid flow during absorbent medium are controlled by the Brinkman model. Through the undisturbed state, both the plate and fluid are in a rigid body rotation by the uniform angular velocity perpendicular to an infinite vertical plate. The perpendicular surface is subject to the homogeneous invariable suction at a right angle to it and the heat on the surface varies about a non-zero unvarying average whereas the warmth of complimentary flow is invariable. The systematic solutions of the velocity, temperature, and concentration distributions are acquired systematically by utilizing the perturbation method. The velocity expressions consist of steady-state and fluctuating situations. It is revealed that the steady part of the velocity field has a three-layer characteristic while the oscillatory part of the fluid field exhibits a multi-layer characteristic. The influence of various governing flow parameters on the velocity, temperature, and concentration are analyzed graphically. We also discuss computational results for the skin friction, Nusselt number, and Sherwood number in the tabular forms.     

平板集热器(倾角)变化工况数值模拟

运用FLUENT数值模拟软件分析了平板集热器(倾角)变化对集热器传热特性的影响,保证其结构参数不变,通过对5组不同倾角(0°、30°、45°、60°、75°)的数值模型进行非稳态模拟,对模拟数据进行分析,得出了平板集热器不同倾角对集热器传热性能变化的影响。     

具有底水边界的水平井压力不稳态特征分析及认识

根据水平井三维渗流特征，在底水油藏情形仍假定顶面为不渗透隔层所封闭，底部则是恒压边界，水平井渗流表现为早期径向流以及稳定流动期，由此进行常规试井分析。以TKxxDH井为例，通过水平井的静压、压恢试井资料结果的对比分析，阐述了不稳定试井资料的应用，为此类油藏油井模型的选择及效果评价提供了可借签的经验。     

A multigrid accelerated hybrid unstructured mesh method for 3D compressible turbulent flow

 A cell vertex finite volume method for the solution of steady compressible turbulent flow problems on unstructured hybrid meshes of tetrahedra, prisms, pyramids and hexahedra is described. These hybrid meshes are constructed by firstly discretising the computational domain using tetrahedral elements and then by merging certain tetrahedra. A one equation turbulence model is employed and the solution of the steady flow equations is obtained by explicit relaxation. The solution process is accelerated by the addition of a multigrid method, in which the coarse meshes are generated by agglomeration, and by parallelisation. The approach is shown to be effective for the simulation of a number of 3D flows of current practical interest. Sponsored by The Research Council of Norway, project number 125676/410 Dedicated to the memory of Prof. Mike Crisfield, a respected colleague     

非稳定井流模型的半解析解

为了提高非稳定渗流计算的计算精度 ,通过数学分析得到了水位传导系数随时间变化时 ,一类非稳定渗流井流模型的半解析解 ,并进行了计算比较     

超音速燃气射流非定常波系的数值研究

根据ＭＵＳＣＬ格式的基本思想，对格式进行了部分修改，数值模拟了超音速燃气射流流场的结构和发展过程。给出了流场谐波系的变化趋势，得到了流场达到稳定状态的时间和稳定后的流动图形。     

佛山市中心组团桥梁群对河道影响的数值分析

在不同频率流量和阻水程度条件下,采用一维明渠非恒定流网河数学模型,分析规划中的佛山市桥梁群对区间河道洪季行洪、枯季水环境的影响,计算洪季不同频率洪峰流量下规划桥梁群对区间河道行洪洪水位、分流比的影响,枯季时规划桥梁群对区间河道过流量、分流比的影响,结果表明,利用一维网河数学模型计算佛山市中心组团规划桥梁群对区间河道断面平均水位、流量和流速的影响,结果有足够的数值精度,是可信的。     

可倾瓦径向气体轴承在低温透平机械中的应用

可倾瓦径向动压气体轴承以其良好的稳定性和自对中能力在低湿透乎机械中获得了广泛的应用。对可倾瓦径向气体轴承的工作原理和在低湿透乎机械中的应用发展情况进行了综述。     

AHMED experiments on hygroscopic and inert aerosol behaviour in LWR containment conditions: experimental results

Hygroscopic NaOH, CsI, CsOH and inert Ag aerosol behaviour at different temperatures and relative humidities (RH) has been studied in a well instrumented and controlled vessel of 1.81 m³ total free volume. Homogeneous thermal-hydraulic conditions for aerosol measurement in the vessel were achieved. The aerosol number and mass concentration were measured continuously during the experiments using a Condensation Nucleus Counter and a Tapered Element Oscillating Microbalance. The particle size distribution and chemical composition in the test conditions were measured by Berner low pressure impactors. In the case of NaOH the half life of the aerosol mass concentration was more than four times longer at low RH (22%) as compared to high RH (96%). The half lives of the CsOH and CsI aerosols were only twice as long at low RH as compared to high RH. Thus at high RH (96–97%) the half lives of CsOH and CsI were twice as long as the half life for the NaOH aerosol. The faster decay of the NaOH aerosol is due to the smaller density decrease of NaOH during water condensation. CsOH particles grew rapidly to their equilibrium size at all humidities. The measured equilibrium size for CsOH aerosol agree well with the calculated particle size at different RHs. Experimental results were also compared with calculations obtained by severe accident computer codes. These calculated results will be presented in a later paper.     

饱和—非饱和土体非稳定渗流数值分析

本文对一般的非饱和渗流有限元计算方法加以改进，有效地消除了非饱和渗流数值计算中存在的数值弥散现象。同时还提出了一种简便有效的逸出面处理新方法，并给出了非饱和非稳定渗流计算的实例。