论文总字数：54956字

摘 要

本文首先对航空发动机气动仿真热物性参数计算的定义、意义、研究重点、研究现状进行了介绍。并根据文献提供的公式与计算方法，在Intel Visual Studio平台使用Fortran语言编写了湿空气的热物性程序，并对程序的计算步骤和计算逻辑进行了详细的描述。该程序共分为七个主要子程序，能够分别计算七种不同已知条件下的湿空气热物性参数，其中包括湿空气的干球温度、湿球温度、露点、饱和压力、水蒸气分压、相对湿度、含湿量、饱和含湿量、饱和度、比容、比焓、湿空气相对分子质量、比热容、动力粘度、导热系数以及密度，并与标准数据对比，二者相对误差控制在1.6%以内，证明了该程序的正确性。

将程序计算出的参数输入到FLUENT算例中进行计算，本文选择ANSYS FLUENT 16.0官方帮助文件中的欧拉模型耦合Eulerian Wall Film（EWF）模型模拟NACA-0012机翼壁面液膜凝结作为FLUENT算例。首先以空气为主相，小液滴为次相作为两相流体计算出了原算例结果，之后分别在只修改主相物性参数、只修改含水量、同时修改主相物性参数和含水量三种情况下计算研究了相对湿度变化对机翼液膜厚度、液膜速度、次相收集效率的影响以及产生影响的主要因素。由计算结果分析可知，三种情况均导致了机翼液膜厚度、液膜速度、次相收集效率数值的增加。其中，只改变主相物性参数时，发生改变的四个参数：比热容、动力粘度、导热系数以及密度只有密度和动力粘度会对结果产生影响，并且随着密度、动力粘度的增加，次相收集效率会降低，但液膜厚度、液膜速度、次相收集效率延机翼壁面的变化趋势并没有发生改变；只改变含水量使得液膜厚度、液膜速度在机翼上的分布和数值大幅改变，次相收集效率改变相对较小，最大液膜厚度出现的位置向机翼下缘后方移动，随着相对湿度的增加，含水量增加，液膜逐渐延机翼壁面向上下缘发展，并且，机翼前缘最薄液膜所在的位置逐渐向x=0m移动；液膜速度分布图上极小值出现的位置与原算例结果相比变化不大，随着含水量的增加，液膜与机翼发生分离的位置向机翼尾部移动；单独改变含水量或单独改变主相物性参数后最大次相收集效率出现的位置并没有发生改变，单独改变含水量对最大收集效率的影响较单独改变主相物性参数产生的影响更小。当同时改变主相物性参数和含水量时，对最终结果的影响程度二者单独改变时产生的影响程度之间。与原算例相比，同时改变物性参数和含水量后，计算获得的液膜厚度、液膜速度数值大于单独改变物性参数后计算获得的数值，小于单独改变含水量后计算获得的数值，而次相收集效率小于单独改变物性参数后计算获得的数值，大于单独改变含水量后计算获得的数值。由此证明了应用该程序能够在FLUENT计算模拟中减少与实际的误差。

关键词：湿空气；热物理性质；Fortran；CFD；FLUENT

Research on Calculation Method of Thermophysical Parameters of Aero-engine Aerodynamic Simulation and Verification of Examples

Abstract

This paper first introduces the definition, significance, research focus, and research status of the calculation of thermal physical parameter of aero-engine aerodynamic simulation. And according to the formulas and calculation methods provided in the literature, the Fortran language was used to write the thermal physical properties of the program on the Intel Visual Studio platform. The calculation steps and calculation logic of the program were described in detail. The program is divided into seven main subprograms, which can calculate the thermal physical parameters of wet air under seven different known conditions, including the dry bulb temperature of wet air, wet bulb temperature, dew point, saturation pressure, water vapor partial pressure , Relative humidity, moisture content, saturated moisture content, saturation, specific volume, specific enthalpy, relative molecular mass of humid air, specific heat capacity, dynamic viscosity, thermal conductivity and density, and compared with standard data, the relative error of the two is controlled at Within 1.6%, proved the correctness of the procedure.

Input the parameters calculated by the program into the FLUENT example for calculation. In this paper, the Euler model coupled with the Eulerian Wall Film (EWF) model in the ANSYS FLUENT 16.0 official help file is used to simulate the NACA-0012 wing wall liquid film condensation as a FLUENT example. . Firstly, the primary calculation phase is air, and the small droplets are secondary phases as two-phase fluids. The original calculation results are calculated. Then, only the main phase physical properties parameters, only the water content, and the main phase physical properties parameters and water content are modified In this case, the effects of changes in relative humidity on the thickness of the wing liquid film, the speed of the liquid film, the efficiency of secondary phase collection, and the main factors affecting the calculation were studied. From the analysis of the calculation results, it can be seen that the three conditions all lead to an increase in the wing liquid film thickness, liquid film speed, and secondary phase collection efficiency. Among them, when only changing the physical parameters of the main phase, there are four parameters that change: specific heat capacity, dynamic viscosity, thermal conductivity and density. Only density and dynamic viscosity will affect the result, and as the density and dynamic viscosity increase, the secondary phase is collected The efficiency will be reduced, but the change trend of liquid film thickness, liquid film speed, secondary phase collection efficiency and wing wall surface has not changed; only changing the water content makes the distribution and value of liquid film thickness and liquid film speed on the wing greatly Changes, the secondary phase collection efficiency change is relatively small, the position where the maximum liquid film thickness appears moves to the rear of the lower edge of the wing, with the increase of relative humidity, the water content increases, the liquid film gradually extends from the wing wall to the upper and lower edges, and, The position of the thinnest liquid film on the leading edge of the wing gradually moves towards x = 0m; The position where the minimum value appears on the liquid film velocity distribution map does not change much from the results of the original calculation example. As the water content increases, the position where the liquid film and the wing are separated moves toward the tail of the wing; The location of the maximum secondary phase collection efficiency did not change after changing the main phase physical property parameters alone. The effect of changing the water content alone on the maximum collection efficiency was smaller than that of changing the main phase physical property parameters alone. When the physical parameters and water content of the main phase are changed at the same time, the degree of influence on the final result is between the degree of influence when the two are changed separately. Compared with the original calculation example, after changing the physical property parameters and the water content at the same time, the calculated liquid film thickness and liquid film velocity are greater than the values calculated after the physical property parameters are changed alone, and are smaller than the calculated values after the water content is changed alone The secondary phase collection efficiency is less than the value calculated after changing the physical property parameters alone, and greater than the value calculated after changing the water content alone. This proves that the application of this program can reduce the actual error in the FLUENT calculation simulation.

Key Words: Humid air; thermophysical properties;Fortran;CFD;FLUENT

目录

摘 要 I

Abstract III

第一章 绪论 1

1.1 选题的背景及意义 1

1.2 国内外发展及研究现状 1

1.2.1 国外发展及研究现状 1

1.2.2 国内发展及研究现状 2

1.3 总结 5

第二章 计算方法 6

2.1 引言 6

2.2 状态参数 6

2.2.1 水蒸气的分压力p_v和饱和压力p_s 6

2.2.2 干球温度、露点温度、绝热饱和温度和湿球温度 6

2.2.3 绝对湿度、相对湿度、含湿量和饱和度 7

2.2.4 比焓和比容 7

2.3 湿空气热力性质的计算公式 7

2.4 计算中的数值方法及其公式 11

2.4.1 水蒸气饱和温度T的计算 11

2.4.2 绝热饱和温度的计算 12

第三章 程序验证 13

3.1 引言 13

3.2 计算步骤与程序逻辑图 13

3.3 计算验证 29

3.3.1 数值比较 29

3.3.2 计算实例 30

3.4 总结 32

第四章 FLUENT算例验证 33

4.1 引言 33

4.2 几何模型和网格生成 33

4.3 物理模型与流体设置 34

4.3 边界条件 35

4.4 求解方法 35

4.5 计算结果分析 36

4.5.1 算例结果 36

4.5.2 自定义湿空气物性 37

4.5.3 更改含水量计算 43

4.5.4 使用自定义湿空气物性与含水量计算 49

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