点燃式发动机火花塞离子电流的数学模型

针对火花塞离子电流的应用问题,基于点燃式发动机在燃烧过程中特定时城内燃气呈等离子体状态的认识,分析研究了发动机燃烧室内燃气离子化的过程；综合运用化学动力学、热力学和等离子体物理学的有关理论和定律,推导出点燃式发动机火花塞离子电流的数学模型．模拟结果表明：离子电流信号强度与火花塞中心电极截面以及火花塞间隙间外加偏置电压成正比,与火花塞间隙成反比；离子电流还受燃气等离子体中带电粒子迁移率和带电粒子浓度的影响,且直接正比于这两个参量；离子电流在特定时城内的变化呈现双峰值状态,这是由于在燃气离子化进程中,带电粒子浓度将呈现两个高峰期．

Mathematical Models of Spark Plug Ion Current in SI Engine

The ionization process of burned gas in combustion chamber of engine is investigated on the basis of the hypothesis that the burned gas is a plasma state in a special stage of the engine combustion process.A math- ematical model of the spark plug ion current in SI engine is established based on the chemical kinetics,thermo- dynamics and plasma physics.The model shows that the strength of the ion current is directly proportional to the section area of center electrode of spark plug and the bias voltage applied cross the spark plug,and inversely proportional to the clearance of the spark plug.The model also indicates that the ion current is directly propor- tional to the move rate and the concentrations of charge particle in burned gas plasma.The mathematical analy- sis of the model shows that two major peaks display during the stage,which is consistent with the fact that the charged particle concentrations,are two peak values during the ionization process of burned gas.