约束空间可燃气体燃烧爆轰特性的数值研究

在可燃气体的输送、贮存、加工和使用过程中,容易发生可燃气体的燃烧和爆炸事故。文中基于有限体积方法,采用五阶WENO格式进行左右状态量的重构后,利用ROE格式进行空间离散,自行开发程序对甲烷氧气的气相爆轰波传播过程进行了数值研究。计算结果表明:在CH4质量分数为10%的混合气体中,高温高压气团可诱导气相发生爆轰,爆轰波以2133.3 m/s的速度传播。在带有障碍物的约束空间内,文中分析了障碍物不同高度、不同间距条件下爆轰波传播时波的绕射、马赫反射等现象,给出障碍物表面压力随时间变化历程和冲量值,揭示波与障碍物的相互作用机理以及由此引发流场的变化规律,为有效地控制可燃气体的燃烧速率、防治爆炸灾害的发生提供理论依据。

Numerical study on the combustion and detonation characteristics of combustible gas in constraint space

For the transportation, storage, processing and use of combustible gases, combustion and explosion acci- dents happen frequently. In the paper, based on the finite volume method, the numerical study on detonation of methane-oxygen premixed gas by Fortran program was conducted by the fifth-order WENO scheme with interpolating left and right states across a cell interface and the Roe Riemann solver, which was low dissipation, strong resolution for the contact discontinuity and shock capture performance. The computed results showed that the propagation speed of detonation wave is 2133.3 m/s ignited by high temperature and high pressure for the mass fraction 10% of CH4. Within the constraint space with obstacles, detonation wave propagation, diffraction, Mach reflection phe- nomenon for the different obstacles heights and spaces were analyzed numerically. The surface pressure and impulse of obstacle structures changing with time were discussed. Moreover, the interaction mechanism of wave and obsta- cle, and the consequent variation of flow field were revealed, which provides a theoretical basis for controlling the combustible gas burning rate and prevention of explosion disasters effectively.