大型客机座舱内考虑送风系统的流动数值模拟策略

发布时间：2018-03-18 09:35

本文选题：飞机座舱　切入点：送风系统　出处：《天津大学》2016年硕士论文　论文类型：学位论文

【摘要】：目前全球有超过1/4的人依靠飞机出行,飞机座舱环境问题日益成为关注热点。大量研究表明,飞机座舱内部的气流组织是影响机舱环境及乘员舒适性的关键因素。因此,准确高效地计算和分析机舱内部气流流动特征对预测和控制机舱内部空气品质及污染物扩散具有重要意义。因飞机舱整体尺寸较大,而舱内个性送风口尺度相对很小以及主送风和个性送风系统结构复杂,确立适用于飞机座舱内气流模拟的高效数值计算策略成为研究舱内气流流动特征的关键问题。首先针对机舱大空间与局部个性送风口之间的高比例尺度问题给舱内复杂气流数值模拟带来的网格质量与数量的挑战,以MD-82飞机单排舱为研究对象,引入适用于个性送风口圆射流粗网格模拟计算的数值耗散修正模型(MDRκ-ε模型),通过与标准κ-ε湍流模型细网格下的射流结果的对比确定该模型能够在有效解决舱内网格匹配问题的同时将射流计算所需网格数量降低90%,进一步确立了与MDRκ-ε湍流模型相匹配的合理的单排舱网格尺度。采用MDRκ-ε模型对等温及空调工况下单排舱内部气流流动特征进行粗网格下的模拟计算,通过计算结果与实验数据的对比验证MDRκ-ε模型适用于舱内主气流的快速正确模拟,可在显著控制座舱主气流模拟计算所需网格数的同时保证良好的计算精度。由此,提出了采用MDRκ-ε模型将个性送风局部射流耦合到机舱主气流流动的座舱气流高效模拟计算策略。进一步针对不同送风流量下的个性送风射流对舱内气流速度、温度分布以及人体热舒适度的影响的研究表明,在个性送风作用下舱内靠近过道乘客周围有更为均匀的流场速度和温度分布,舒适感更好。且随个性送风口送风量增大,个性送风口对乘客的影响无论是速度还是温度都会明显增强,但速度变化范围均集中在个性送风口中轴线附近,无强烈放射状扩散。将数值模拟策略应用于飞机七排舱气流流动特征的模拟计算,在每排座舱送风条件一致情况下,获得了七排舱每排座舱周期性的主气流分布规律,同时确定在座舱过道、乘客头顶上方及肩部存在速度为0.05~0.1m·s-1的弱纵向流动。本文座舱气流模拟策略可为飞机整舱流场的快速正确模拟计算奠定基础,且带个性送风口单排舱及七排舱内部气流分布特征的研究结果可以为飞机座舱内部环境及污染物控制提供理论依据。
[Abstract]:At present, more than 1/4 people in the world rely on aircraft travel, and the problem of cabin environment has become a hot issue. A large number of studies show that the airflow distribution inside the cockpit is the key factor affecting the cabin environment and crew comfort. Accurate and efficient calculation and analysis of the airflow characteristics in the cabin is of great significance in predicting and controlling the air quality and pollutant diffusion in the cabin. However, the scale of individual tuyere in the cabin is relatively small, and the structure of the main air supply and individual air supply system is complex. It is a key problem to study the characteristics of airflow in cockpit to establish an efficient numerical calculation strategy suitable for airflow simulation in aircraft cockpit. Firstly, the high-proportion scale problem between the large space of engine room and the local individual tuyere is discussed. The challenges of mesh quality and quantity brought by numerical simulation of internal complex airflow, Taking the single row cabin of MD-82 aircraft as the research object, A numerical dissipation correction model (MDR 魏-蔚 model), which is suitable for the simulation of individual tuyere round jet with coarse mesh, is introduced. By comparing the jet results with the standard 魏-蔚 turbulence model under fine mesh, it is determined that the model can effectively solve the problem of in-cabin network. The grid matching problem simultaneously reduces the number of grids needed for jet calculation by 90%, and further establishes the reasonable grid scale of single row cabin that matches the MDR 魏-蔚 turbulence model. The MDR 魏-蔚 model is used to analyze the internal airflow of single row cabin under isothermal and air conditioning conditions. The flow characteristics are simulated with coarse mesh. The comparison between the calculation results and the experimental data shows that the MDR 魏-蔚 model is suitable for the fast and correct simulation of the main airflow in the cabin. In this paper, the MDR 魏-蔚 model is used to couple the local jet of individual air supply to the main airflow of cabin. The simulation strategy of air flow efficiency in cockpit is put forward, which is further aimed at the velocity of individual air jet in the cabin under different air flow rate. The research on the influence of temperature distribution and thermal comfort of human body shows that under the action of individual air supply, there is a more uniform velocity and temperature distribution in the cabin near the aisle passenger, and the comfort is better, and with the increase of the air supply volume of the individual tuyere, The influence of individual tuyere on passengers will obviously increase, both in speed and temperature, but the range of velocity changes is concentrated near the central axis of individual tuyere. There is no strong radial diffusion. The numerical simulation strategy is applied to the simulation calculation of the airflow characteristics of the aircraft's seven-row cabin. Under the same air supply conditions of each cabin, the periodic main airflow distribution law of the seven-row cabin is obtained. At the same time, it is determined that there is a weak longitudinal flow over the top of the passenger's head and shoulders in the cockpit corridor with a velocity of 0.1m 路s ~ (-1). The airflow simulation strategy of the cockpit in this paper can lay a foundation for the rapid and correct simulation of the flow field in the whole cabin of the aircraft. The results of the study on the characteristics of airflow distribution in single-row and seven-row cabins with individual tuyere can provide a theoretical basis for the internal environment of aircraft cockpit and the control of pollutants.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V223

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