单峰放热率曲线的双韦伯函数拟合探讨

A Study on Simulation of Single-Hump-Shaped Heat Release Rate by Dual Wiebe's Functions

运用优化理论和方法,建立了单峰形状放热率曲线的双韦伯函数拟合问题的最优化方法模型,提出了充分必要的约束条件。通过对典型的单峰放热率曲线的拟合和分析,指出韦伯函数在拟合扩散燃烧阶段放热率时存在着不足;并相应提出了一种修正的韦伯函数用来拟合扩散燃烧放热率,初步探讨了这种修正的物理意义。对若干单峰放热率曲线的拟合表明,这种修正是合理的,拟合效果令人满意。

An optimum simulation model of single-hump-shaped heat release rates by dual Wiebe's functions is set up using the optimization theory. Its necessary and full constraining conditions are put forward. The analysis of typical heat release rate reveals that there is a demerit of Wiebe's function to simulate the diffuse combustion rate. Then a modified Wiebe's function is formulated for a better simulation. The calculation results of several single-hump-shaped heat release rate show that the modification is quite reasonable and satisfactory.