喷油提前角对生物柴油高压共轨柴油机性能影响的数值模拟

Numerical simulation of the influence of spray advance angle on the performance of biodiesel high pressure common rail diesel engine

利用CFD分析软件AVL FIRE对高压共轨柴油机燃用B20(掺比20%生物柴油)燃料的燃烧过程进行模拟,通过建立三维仿真模型研究发动机在不同喷油提前角下燃用该燃料的燃烧过程,并对模型的准确性进行验证。计算不同喷油提前角下发动机燃烧过程中放热率、缸内压力、缸内平均温度、放热量等的影响;模拟出不同配比混合燃料下高压共轨柴油机的各方面的性能。模拟结果得出:随着喷油提前角的增大,高压共轨柴油机的动力性提高,燃油消耗率减小,Soot排放减小,但NO_X排放增大。

Using CFD simulation tool FIRE to simulate the combustion process that a high pressure common rail diesel engine use B20（the fuel mixed with 20% biodiesel）at different spray advanced angles,and a 3D simulation model was established and validated.Using the established model to study the combustion process of the mixed fuel,calculating the influence of spray advance angle on the mean pressure in the cylinder、accumulated heat release and rate of heat release and so on;Various performance of the diesel engine was calculated.The result shows that with the spray advance angle increasing,the power of the diesel increases,the break specific fuel consumption decreases,the Soot emission decrease,while the NOX emission increases.