采用不同气相燃烧模型模拟含硼燃气扩散燃烧过程

Numerial simulation on boron-based gas diffusion combustion by different gaseous combustion models

为解决固冲发动机补燃室中含硼富燃燃气湍流扩散燃烧模型选择问题,以设计的平行进气燃烧装置为物理模型,以King点火模型与L-W燃烧模型为硼粒子点火和燃烧模型,湍流燃烧分别采用有限速率/涡耗散模型、涡耗散模型、有限速率模型,采用数值模拟方法对其燃烧过程进行数值模拟,获得了理想的含硼燃气湍流扩散燃烧的火焰结构、流场规律,得到不同燃烧模型下的燃烧特性。不同湍流燃烧机理对气相燃烧过程和颗粒相燃烧过程存在影响不同。不同影响的内在机理说明,燃烧模型模拟不同过程时存在能力差异。对于气相反应的模拟,涡耗散模型最剧烈,有限速率/涡耗散模型次之,有限速率模型最缓慢;对于硼粒子点火反应,有限速率/涡耗散模型最剧烈,有限速率模型次之,涡耗散模型最缓慢;对于硼粒子燃烧反应,涡耗散模型最快,有限速率模型次之,有限速率/涡耗散模型最缓慢。

For selection of boron-based fuel-rich gas turbulent diffusion combustion model in solid ramjet rocket secondary com- bustion chamber, parallel intake combustion apparatus was designed as physical model. On foundation of boron particles King igni- tion model and L-W burning model, turbulent diffusion combustion process was simulated by numerical simulation methods which a- dopted Finite-Rate/Eddy-Dissipation model, Eddy-Dissipation model, Laminar Finite-Rate model respectively. Flame structure and flow field characteristics of turbulent diffusion combustion were acquired, and combustion characteristics of different combustion models were obtained. Different turbulent combustion mechanisms have different influence on gaseous combustion process and parti- cle combustion process, and inherent mechanism of different influence reveals that combustion model has different ability to simulate different process. The most intensity of gas phase reactor simulation is Eddy-Dissipation model ,followed by Finite-Rate/Eddy-Dissi- pation model, and Laminar Finite-Rate model is the slowest;when boron particle ignition reaction is simulated, Finite-Rate/Eddy- Dissipation model is the most dramatic, followed by Laminar Finite-Rate model, and Eddy-Dissipation model is the slowest; but Eddy-Dissipation model is the fastest for boron particle combustion reaction, followed by Laminar Finite-Rate model, and Finite- Rate/Eddy-Dissipation model is the slowest.