西安交通大学：《数值传热学》课程教学资源（课件讲稿）第二章 计算区域及控制方程的离散 Discretization of Computational Domain and Governing Equations

Interfacesbylowercases(小写字母）wande(x)w(ax)Distancebetweennodes?1)(i+(i-GridlineETInterfaceDistancebetweeninterfacesW2.1.3 Introduction to different types of grid systemand generation method(1）Structuredgrid（结构化网格)：Node positionlayout（布置）is in order（有序的），and fixedfortheentiredomain6/44

6/44 2.1.3 Introduction to different types of grid system and generation method （1） Structured grid (结构化网格)：Node position layout（布置）is in order (有序的）, and fixed for the entire domain. Interface Gridline Distance between nodes Distance between interfaces Interfaces by lower cases(小写字母) w and e

(2)Unstructuredgrid（非结构化网格）：Nodepositionlayout(布置) is in disorder, and may change from node tonode. The generation and storage (存储) of the relationship ofneighboring nodes are the major work of grid generation.Structured (b)Structured (a)5elementsUn-structured6neighboringelements7/44

7/44 （2） Unstructured grid (非结构化网格)：Node position layout(布置) is in disorder, and may change from node to node. The generation and storage (存储) of the relationship of neighboring nodes are the major work of grid generation. Structured（a) Structured（b) Un-structured 5 elements 6 neighboring elements

Both structured and unstructured grid layout(节点布置)have two practices（实施）：outer node and innernode(3)Outer nodeand inner nodeforstructured grid(a) Outer node method: Node is positioned at thevertexofasub-domain(子区域的角顶）；Theinterfaceisbetween two nodes; Generating procedure: Node firstandinterfacesecond---calledPracticeA(byPatankar)orcell-vertexmethod（单元顶点法）Sub-D极坐标个孤度(radian)直角坐标6CV|Cylindrical (2D)Cartesian(2D)Polar8/44

8/44 Both structured and unstructured grid layout (节点布置) have two practices（实施）：outer node and inner node. （3）Outer node and inner node for structured grid (a) Outer node method：Node is positioned at the vertex of a sub-domain(子区域的角顶)；The interface is between two nodes；Generating procedure：Node first and interface second-called Practice A (by Patankar) ， or cell-vertex method (单元顶点法). Sub-D Cartesian(2D) CV Cylindrical（2D） Polar (radian)

(b)Innernodemethod:Nodeis positioned atthecenter of sub-domain,Sub-domain is identical to controlvolume; Generating procedure: Interface first and nodesecond,called PracticeB(byPatankar),or cell-centered method【（单元中心法）Axe(斧头)1radian(1弧度)Sub-domainisthecontrolvolume9/44

9/44 (b) Inner node method：Node is positioned at the center of sub-domain; Sub-domain is identical to control volume; Generating procedure: Interface first and node second, called Practice B (by Patankar) , or cell￾centered method（单元中心法）. Sub-domain is the control volume 1 radian （1弧度） Axe (斧头)

Generating procedure of Practice B10/44

10/44                                                                         Generating procedure of Practice B