TY - JOUR
TI - Optical study on needle lift and its effects on reacting diesel sprays of a single hole solenoid injector
AU - Xuan Tiemin
AU - Sun Zhongcheng
AU - Lu Peng
AU - Zhong Wenjun
AU - Si Zhanbo
AU - He Zhixia
AU - Wang Qian
AU - Chen Zhou
AU - Guan Wei
JN - Thermal Science
PY - 2021
VL - 25
IS - 5
SP - 3763
EP - 3773
PT - Article
AB - Precise control of needle lift provides one possibility to control the diesel spray and combustion process actively. However, most studies of needle lift focus on internal flow or near nozzle spray. Little work has been performed on its effects on reacting spray. In this work, one way to change the needle lift profile of a solenoid injector has been developed and the relationship between needle lift and reacting spray has been investigated. The needle movement was detected with an optical nozzle. In addition, the visualization of reacting sprays of the same injector equipped with a single hole nozzle was conducted in a combustion chamber. Some simulations were also performed to assist the analysis. The results show that the needle lift profile can be regulated by changing the thickness of an adjusting pad. It seems the different needle lift profiles do not bring in significant influences on reacting spray characteristics. The CFD results indicate that it is mainly caused by the similar internal flow characteristics which do not show strong variation when needle lift is higher than 0.1 mm. However, the discharge coefficient and velocity coefficient decrease sharply when needle lift is smaller than 0.05 mm because of the “throttle” effect.