文档介绍：题目:半圆螺旋管流动和传热特性研究
摘要
螺旋管是一种在动力、化工、石油和核工业中都有广泛应用的空间曲线管。按其截面形状来分,可分为圆形、环形、矩形、半圆形螺旋管等。由于流体在螺旋管道中旋转流动的过程中产生的离心作用使它与直管中的流动有很大的不同,正由于此,其产生的二次流动增加了流体的热扰动从而起到强化传热的作用。而半圆螺旋管,更是在人们的生产和生活中已经取得的越来越广泛的应用。
目前所研究的问题主要是基于实验分析与数值模拟两种。实验分析方法所研究的问题是基于相似原理的指导,通过对实际问题进行实验模拟的方式来确定的,在工程研究中具有广泛的应用,但相比而言,耗时较长,成本相对比较高。本文采用数值模拟的方法对半圆螺旋管进行分析,在应用fluent软件和计算流体力学(CFD)相关知识的基础上,对半圆螺旋管管道内流体湍流流动状态下的流场进行数值模拟,分析半圆螺旋管内流场及影响因素,包括轴向速度的分布、压降、雷诺数以及二次流对流场的影响。本文首先概述了半圆螺旋管的应用背景及分析意义,对gambit和fluent进行了系统的介绍,而后进行了数值模拟及分析。通过建模,导入gambit中划分网格定义边界条件,在fluent中设定初始条件进行数值模拟,进一步分析在湍流条件下流体在半圆螺旋管中换热的影响因素。通过数值模拟得出了结论,入口雷诺数对半圆螺旋管的整个流场影响较大,管道内流体压降与流体流速大小成正比。速度越大半截面管中流体压降越大。由此,我们可以增大管道雷诺数从而达到改善流场流动的目的。同时,流体入口速度的大小又影响整个管子中流体的二次流的流型。速度较小时,二次流呈对称分布。当速度较大时二次流向外部偏离且不明显。因此,选择合理的入口速度,可以使流体在流场中达到优化配置。数值模拟及分析的结果对工业生产具有指导意义,可以更好的指导应用进行实践工作。
关键词: 半圆螺旋管;传热特性;流动性;三维模拟
Title: Semi-circle spiral flow and heat transfer Characteristics
Abstract
The spiral is a power, chemical; oil and nuclear industry have widely space curve tube. According to their cross-section shape can be divided into round, circular, rectangular, semi-circular spiral. Centrifugation so that it produced in the process of the rotational flow of fluid in the spiral pipe and pipe flows are very different, precisely because of this, which produces a secondary flow to increase the thermal disturbance of the fluid to play the enhanced mass hot. The semi-circular cross-section spiral has been made more widely used in the production and living of the people.
Now the study is based mainly on the experimental analysis and numerical simulation. Experimental analysis of the study is based on similar guiding principles, practical issues of experimental simulation approach to identify, and in engineering research in a wide range of applications, but parison, the time is longer, the cost is relatively high. In this paper, numerical simulation method is used to analysis the spiral pipe with semi-circular section. It is based on the knowledge of software putational fluid dynamic