内燃机缸内近壁气流速度及温度分布特性的数值分析

为解决内燃机缸内近壁处的气体流动和传热问题，研究了内燃机缸内近壁处的气流温度和速度分布特性．以二维可压缩平面边界层流动方程为基础，根据准稳态能量定律的假设，以F因子作为修正系数，建立了曲面边界层的二维模型，并计算了温度和速度边界层在曲面上的分布．结果表明：热边界层和速度边界层的厚度数量级均为10^-3m；壁面温度高处热边界层厚，反之较薄；气流速度梯度较大处速度边界层薄，反之较厚．计算结果得到了激光实验测量结果的验证．

Numerical Analysis on In-Cylinder Air Motion Velocity and Temperature Distribution Near Wall in Internal Combustion Engine

To solve the problem of gas flow and heat transfer near wall in cylinder of internal combustion engine,the characteristic of temperature distribution and air motion velocity near wall in cylinder of internal combustion engine is investigated.A two-dimensional curved boundary layer model is proposed, based on the two-dimensional boundary layer theory, assuming that the temperature and velocity profile follows the quasi steady state energy law, with the F factor working to revise the error of curved flow. The distribution of temperature and velocity boundary layer on curve is calculated. The calculated results demonstrate that both order of magnitude the thickness of temperature and velocity boundary layer are 10~(-3) m. The thermal boundary layer is thick near the wall where the temperature is high, whereas the thermal boundary lager is thin. The velocity boundary layer is thin near the wall where the velocity gradient is high, on the contrary, it is thick. The calculated results are verified by the measured results of laser experiments.