项目名称: 油滴周围流动和火焰结构与新亚网格两相小火焰模型研究
项目编号: No.51266008
项目类型: 地区科学基金项目
立项/批准年度: 2013
项目学科: 能源与动力工程
项目作者: 李科
作者单位: 内蒙古科技大学
项目金额: 58万元
中文摘要: 实验观测表明,油滴燃烧和液雾湍流燃烧都有不同的瞬态流动和火焰结构,但是未能给出定量的规律。目前的数值模拟中,不论是点源颗粒的直接模拟、大涡模拟,还是雷诺平均模拟,都是基于冷油滴在气体火焰中蒸发的模型,将蒸发和燃烧解耦,分别采用油滴纯蒸发和纯气体燃烧模型,冷颗粒阻力系数,忽视湍流变动规律。模拟结果不能合理地预测真实液雾燃烧过程。液雾燃烧的全尺度直接数值模拟,应当能给出真实过程,但是计算量十分巨大,难以实现。本项目对油滴燃烧进行全尺度直接数值模拟,并且进行实验研究,取得不同的相对速度、颗粒尺寸、环境温度和湍流度下的油滴燃烧时周围的流动和火焰结构,蒸发规律,阻力和湍流变动规律。用此研究结果构造新的亚网格两相小火焰模型,用于液雾湍流燃烧的大涡模拟,并对统计模拟结果进行实验检验,从而得到更符合实际的液雾火焰结构和更合理的液雾燃烧的CFD数值模拟方法。
中文关键词: 燃烧油滴;液雾燃烧;数值模拟;大涡模拟;多模态
英文摘要: The experimental observations show that combusting droplets and spray turbulent combustion has different transient flow and flame structure, but failed to give the law of quantitative. Numerical simulations, whether PDNS(Particles Source Direct Numerical Simulation), LES(Large Eddy Simulation) or RANS(Reynold Averaged Navier-Stokes), are all based on the evaporation model of cold droplets in the gas flames where the evaporation and burning are decoupled, pure oil droplets evaporate,pure gas combustion model and cold particles resistance coefficient are adopted, turbulent modulation is neglected. So,the numerical simulation results can't predict the true spray turbulent combustion process reasonably. FDNS(Fully-Resolved Direct Numerical Simulation) should be able to give a real process. However, because of demanding a huge amount of storagede and high speed computer, it is difficult to achieve. This project presents a multi-scale analysis method which simulate combusting droplets using the FDNS and experimental research firstly.And then obtaining the evaporation rate, resistance and turbulent modulation rules with the conditions of the relative speed, different particle size, environment temperature and turbulence intensity of surrounding combusiting droplets of flow and flame structure. Then constructing a new
英文关键词: Combusting Droplets;Spray Combustion;Numerical Simulation;Large Eddy Simulation;Multi-Mode