摘要随着社会发展,人们对火焰燃烧问题的研究越来越受到重视,为了能够应对日益 严重的能源危机,深入研究燃烧问题,对换热技术的强化有重要意义,同时研究喷射 火焰的燃烧特性及相关规律,了解其燃烧机理,这在消防安全领域也有重要意义。83978
本文以丙烷喷射火焰为研究对象,首先基于火焰燃烧综合测试仪进行实验分析, 并基于 FDS 软件对丙烷喷射燃烧进行数值模拟。通过火焰表面温度、火焰形状、速度、 密度、热释放率等实验和数值模拟数据分析,认为:
(1)温度,速度,热释放率在总体分布规律上是中心高边缘低的分布规律,密度场 分布是中心低边缘高的分布规律;
(2)随着流量增大,温度,热释放率最大值出现的位置在火焰竖直方向上上升,速 度最大值的位置下降,密度最小值位置下降;
(3)温度,速度,热释放率,密度的变化梯度均在各物理量达到最值的时候最大; (4)以上所有规律均在火焰条件稳定的情况下得出,火焰不稳定时,变化规律将改
变。
关键词:丙烷;喷射火焰;数值模拟;实验研究
Abstract In this paper, we mainly study the general rules and flame characteristics of propane jet flame。 With the development of society, people on the flame combustion research more and more attention, in order to be able to cope with the increasingly serious energy crisis, in-depth study of combustion, heat transfer technology of reinforcement significance, also of the spray flame combustion characteristics and related rules, to understand the mechanism of combustion, which in the field of fire safety also important significance。 The paper is pided into three parts。 In the first part, based on the experimental analysis of the flame combustion comprehensive test instrument, the second part establishes the combustion model to analyze the combustion model, and the third part compares the two parts。 Through the analysis of the surface temperature of flame and flame shape。 It is proved that the combustion model simulation result is reliable, then carries on the analysis to other physical quantities, obtained in the propane jet fires the general rules and characteristics of the flame for the following several points:
(1)the distribution of temperature, velocity and heat flux in the overall distribution is the distribution of the central high edge, and the distribution of the density field is the center of the low edge distribution;
(2)with the increase of flow rate, temperature, the position of the maximum value of heat flux appears in the vertical direction of the flame, the position of the maximum velocity decreases, and the position of the minimum density decreases;
(3)the temperature, velocity, heat flux density, and the change of density gradient are the biggest when the physical quantity reaches the maximum;
(4)above all the laws are stable under the conditions of the flame, the flame is not stable, the change will change the law。
Keywords: propane;flame;numerical simulatio;experiment
目录
第一章 绪论 1
1。1 研究的目的及意义 1
1。2。1 国外燃烧火焰数值模拟 1
1。2。2 湍流燃烧模拟理论 3
1。2。3 燃烧模拟的简化 4
1。3 论文主要研究内容