不同运行参数和结构尺寸气缸内流动的数值计算

内燃机缸内流动是极其复杂的三维湍流流动,其流动具有强压缩性、强旋转和各向异性的特点,正确地模拟和分析内燃机的燃烧和排放,离不开对缸内湍流运动的正确描述和模拟。为了考察运行参数和结构尺寸对内燃机缸内湍流特性的影响,用修正的非线性三方程模型对不同运行参数及燃烧室几何尺寸的缸内流动进行计算,特别考察挤流和旋流对湍能的影响,给出了用非线性三方程模型计算得到的结果,结果表明改变内燃机运行参数及燃烧室几何尺寸对缸内流动及湍流特性有很大的影响,旋流和挤流共同作用能有效改善压缩后期缸内湍流特性。

Numerical Simulation of in- Cylinder Flows in Various Working Parameters and Combustion Chamber Configurations

Gas flows in internal combustion engine cylinders are invariably complicated, three - dimensionalturbulent flows. These flows in engines have the characteristic of highly compressible, rotational andanisotropic. For accurate simulating and analyzing the combustion and exhaust, it is necessary to describe andsimulate the turbulent flow in cylinder. The modified non - linear three equation model was applied to calculatethe in - cylinder turbulent flows for engines with various working parameters and combustion chamberconfigurations, especially the effect of extrusion flow and turbulent flow on turbulent energy. Numerical resultshows that working parameters and combustion chamber configurations have great influences on the in - cylinderflow and turbulence characteristics. And co-operative action of turbulent flow and extrusion flow can effectivelyimprove the in- cylinder turbulence characteristics during later stage of compression.