中介尺度活塞式内燃机氢氧燃烧过程的数值模拟

Numerical simulation of hydrogen-air combustion in meso-scale IC engine

中介尺度条件下的氢氧预混燃烧,其燃烧速率主要由化学反应速度决定。于是采用层流有限速率模型,运用详细氢氧19步基元反应化学动力学机理和动态网格数值方法,对中介尺度准气体动力循环活塞式热力发动机超高燃烧负荷率氢氧预混燃烧过程进行了模拟。研究表明:中介尺度移动边界微小封闭空间的氢氧预混燃烧具有稳定性;采用表面炽热点火形式的中介尺度准气体动力循环的活塞式内燃机,能够实现工质高温吸热、内能增加和对外做功的完整热力学过程;而循环周期、初始压力、相对燃空比等运行参数对移动边界微小封闭空间的氢氧燃烧过程具有复杂的影响。

The burning rate of hydrogen air pre-mixture on meso-scale is mainly determined by its chemical reaction rate. So a Laminar Finite Rate Model, the gas phase reaction mechanism for the combustion of hydrogen-air mixture which consists of 19 reversible elementary reactions and the dynamic mesh method are adopted to simulate the combustion of hydrogen-air mixture in a meso-scale IC engine which operates a quasi gas power cycle under ultrahigh combustion load. The combustion of hydrogen-air mixture on meso- scale in the micro combustion chamber with moving boundary can be stable. The complete thermodynamic process of heat addition, internal energy increasing, and a boundary work output producing during expansion can be perfectly achieved in the closed combustion system of the meso-scaled IC engine igniting the hydrogen-air mixture by wire surface of high temperature. However, running parameters such as cycle period, initial pressure and fuel/air ratio have complex effects on the hydrogen-air combustion of micro closed container with moving boundary.