温度对液态正庚烷喷射特性影响的PIV实验

Influence of temperature on n-heptane liquid injection characteristics through PIV experiment

基于粒子图像测速仪(PIV)实验系统研究了正庚烷在不同温度、不同压力下的射流特性,用于指导发动机燃油供给系统设计。通过对正庚烷在不同喷射压力、不同温度下射流宏观图像的拍摄和分析,研究了正庚烷在温度不断提高的条件下射流特性的变化规律。结果表明:液态正庚烷喷射特性中,锥角最大值随压力增大而增加;随着温度的不断提高,射流锥角、射流最大宽度呈现先增加后减小的规律。在实验中得到:当射流锥角明显增大,压力小于0.5 MPa时,温度随压力增大而升高;压力大于0.5 MPa时,温度随压力增大而降低。

N-heptane injection characteristics under different temperatures and pressures is studied basing on PIV （particle image velocimetry） experimental system and is used for the design of engine fuel supply system. Under the condition of temperature rising, macro images have been taken at different temperatures and injection pressures for the study of n-heptane jet characteristics. Results show that among the liquid n-heptane injection characteristics, maximum spray-cone angle increases with increasing pressure; while, with the increasing temperature, spray- cone angle and injection maximum width first increase and then decrease. In the experiment, when the pressure is less than 0.5 MPa, temperature of injection cone increases significantly with increasing pressure. When the pressure is greater than 0.5 MPa, the temperature of this moment decreases with increasing pressure.