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毕业论文网 > 毕业论文 > 理工学类 > 轮机工程 > 正文

微沟槽在船体表面减阻中的应用毕业论文

 2021-03-21 00:49:32  

摘 要

本文研究微沟槽在船体表面中的应用,由贝壳非光滑表面的微沟槽得到启发,研究相关论文,基于Wlash研究的微沟槽简化,由此确定了微沟槽形貌尺寸,并按相关尺寸构建了物理模型。通过对物理模型内流体理论分析,确定了其网格模型。为确保所选定的数值模拟方法的正确性,本文有对光滑平板进行所选定的数值模拟方法的数值模拟,把得到的数值模拟结果与由近似计算公式计算出的计算结果进行计算误差比较,发现所得所有计算误差在范围之内。本文紧接着对不同尖角V形微沟槽进行数值模拟。本文的数值模拟主要研究近壁面区域的剪切应力、湍动能分布。比较五种不同尖角的V形微沟槽的减阻效果,研究表明V形微沟槽尖角在小于90°时都具有减阻效果,其中尖角为75°的V形微沟槽的湍动能最低和减阻率最高,即其减阻效果最佳,减阻率为5.016%。本文研究V形沟槽皆为对称V形沟槽。

关键词:数值模拟、微沟槽减阻、船舶减阻

Abstract

Paper application of micro grooves on the surface of the hull from shells of non-smooth surface of the Groove and get inspired, research papers, micro Groove simplification based on Wlash research, thereby determining the micro Groove shape size and dimensions constructing physical models. Theoretical analysis of fluid in the physical model, determine its meshes. To ensure the correctness of the selected numerical simulation method, we have selected the smooth flat numerical simulation method of numerical simulation and numerical simulation of received results from an approximate formula to calculate the results of calculation errors, find that all errors in the range. This article followed by different cusp numerical simulation of v-shaped micro grooves. This numerical simulation studies of near-wall region of shear stress, turbulent kinetic energy distributions. Comparing five different angle of v-shaped micro grooves on drag reduction effect, research has shown that v-shaped micro Groove angle is less than 90 ° with drag reduction effect, which pointed to 75° v-shaped micro grooves on the turbulent kinetic energy minimum and drag reduction rate is the highest, best drag reduction effect, drag reduction reach 5.016%. V-shaped grooves are investigated in this paper is the symmetric v-shaped grooves.

Key words: numerical simulation of drag reduction, micro-grooves, ship drag reduction

目 录

第1章 绪论..................................................................1

1.1 微沟槽在船体表面减阻中的应用的研究意义..............................1

1.2 微沟槽减阻国的内外现状..............................................1

1.2.1 微沟槽减阻的国外现状..........................................1

1.2.2 微沟槽减阻的国内现状..........................................2

1.3 论文的工作简介......................................................4

第2章 湍流以及边界层........................................................5

2.1 前言................................................................5

2.2 湍流理论............................................................5

2.2.1 黏性流体的两种流动状态........................................5

2.2.2 湍流..........................................................5

2.3 边界层理论..........................................................6

2.3.1 边界层的基本概念..............................................6

2.3.2 平板边界层的近似计算与比较....................................6

2.4 本章小节............................................................8

第3章 数值模拟..............................................................9

3.1 前言................................................................9

3.2 基本理论............................................................9

3.2.1 流体流动的控制方程............................................9

3.2.2 数值的模拟方法...............................................10

3.2.3 数值模拟的其他选择...........................................10

3.2.4 边界条件.....................................................10

3.3 三维建模和网格划分.................................................11

3.3.1 三维建模.....................................................11

3.3.2 网格划分.....................................................12

3.4 本章小结...........................................................14

第4章 数值模拟结果........................................................15

4.1 前言...............................................................15

4.2模型准确性验证......................................................15

4.2.1 光滑平板阻力的验证...........................................15

4.2.2 模型适用范围的验证...........................................15

4.3 不同尖角比对减阻性能的影响.........................................16

4.3.1 速度分布分析.................................................16

4.3.2 剪切应力分析.................................................18

4.3.3 湍动能分析...................................................19

4.4 本章小结...........................................................21

第5章 结论和展望...........................................................22

参考文献...................................................................23

致谢.......................................................................24

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