流固耦合作用下真实人体上呼吸道呼吸流涡结构演化的数值仿真

Numerical simulation on vortex evolution of airflow in realistic human upper respiratory tract under the effect of fluid-solid interaction

通过构建真实人体上呼吸道三维规范模型,运用大涡模拟数值方法,对考虑流固耦合作用的低强度循环呼吸模式下人体上呼吸道内的呼吸流进行了数值仿真,研究分析了人体口喉模型及气管支气管内的气流涡结构及其演化过程。结果表明,循环吸气过程中,气流在口腔中部以及舌苔上部形成多个涡管,在声门部位形成强烈的射流,在气管前壁出现马蹄涡,到气管中部大尺度涡结构逐步消失,支气管中只剩下一系列小尺度涡结构;循环呼气过程中,气流在气管底部产生较为复杂的涡结构,随着气流在气管内的融合,涡强度逐步减弱,在咽喉后壁形成拱状涡,气流进入口腔后,涡结构破裂,涡量扩散,没有较大的涡结构产生。

The airflow in human upper respiratory tract was simulated by using large eddy simulation method with 3D standardized model of realistic human upper respiratory tract under the effect of fluid-solid interaction and cyclic respiratory pattern,and the vortex evolution of airflow in human mouth-throat as well as trachea and bronchi was analyzied.The results show that several vortex tubes are formed in the central of mouth and on the surface of tongue coating,a turbulence j et ej ected towards to the anterior wall of the trachea appears in the glottal regional,the horseshoe vortexe which is similar to horseshoe appears on the anterior wall of the trachea in the phase of inhalation;In the phase of exhalation,the complex vortex structure appears on the bottom of the trachea,the vorticity in the trachea decreases and only a stronger vortex tube extends along the trachea with the airflow streams converging, and arch vortex is formed on the posterior wall of throat,then the vortex structure breaks up and there is no big vortex structure in the mouth.