The high-speed digital imaging technique is applied to observe the developing process of flash boiling spray of dimethyl ether at low ambient pressure, and the effects of nozzle opening pressure and nozzle hole diamet...The high-speed digital imaging technique is applied to observe the developing process of flash boiling spray of dimethyl ether at low ambient pressure, and the effects of nozzle opening pressure and nozzle hole diameter on the spray shape, spray tip penetration and spray angle during the injection are investigated. The experimental results show that the time when the vortex ring structure of flash boiling spray forms and its developing process are determined by the combined action of the bubble growth and breakup in the spray and the air drag on the leading end of spray; with the enhancement of nozzle opening pressure, the spray tip penetration increases and the spray angle decreases. The influence of nozzle hole diameter on the spray tip penetration is relatively complicated, the spray tip penetration is longer with a smaller nozzle hole diameter at the early stage of injection, while the situation is just opposite at the later stage of injection. This paper establishes that the variation of spray angle is consistent with that of nozzle hole diameter.展开更多
This study discusses about the optimization of spray characteristics of biodiesel fuel in a spray chamber.Three factors namely,fuel injection pressure,fuel temperature and fuel blends were chosen as the influencing fa...This study discusses about the optimization of spray characteristics of biodiesel fuel in a spray chamber.Three factors namely,fuel injection pressure,fuel temperature and fuel blends were chosen as the influencing factor for the set objective.Four levels were chosen in each factor and spray tip penetration,spray cone angle and Sauter mean diameter(SMD) were taken as the response variables.Experiments were designed by employing design of experiments method and Taguchi full factorial array was used to conduct the tests with different levels of the chosen factors.Multi Response Signal to Noise ratio(MRSN) was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi's parametric design.Confirmation experiments were conducted for the obtained optimum combination level of factors and the results were compared with the normal operating conditions and significant improvement were observed in the response variables.展开更多
文摘The high-speed digital imaging technique is applied to observe the developing process of flash boiling spray of dimethyl ether at low ambient pressure, and the effects of nozzle opening pressure and nozzle hole diameter on the spray shape, spray tip penetration and spray angle during the injection are investigated. The experimental results show that the time when the vortex ring structure of flash boiling spray forms and its developing process are determined by the combined action of the bubble growth and breakup in the spray and the air drag on the leading end of spray; with the enhancement of nozzle opening pressure, the spray tip penetration increases and the spray angle decreases. The influence of nozzle hole diameter on the spray tip penetration is relatively complicated, the spray tip penetration is longer with a smaller nozzle hole diameter at the early stage of injection, while the situation is just opposite at the later stage of injection. This paper establishes that the variation of spray angle is consistent with that of nozzle hole diameter.
文摘This study discusses about the optimization of spray characteristics of biodiesel fuel in a spray chamber.Three factors namely,fuel injection pressure,fuel temperature and fuel blends were chosen as the influencing factor for the set objective.Four levels were chosen in each factor and spray tip penetration,spray cone angle and Sauter mean diameter(SMD) were taken as the response variables.Experiments were designed by employing design of experiments method and Taguchi full factorial array was used to conduct the tests with different levels of the chosen factors.Multi Response Signal to Noise ratio(MRSN) was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi's parametric design.Confirmation experiments were conducted for the obtained optimum combination level of factors and the results were compared with the normal operating conditions and significant improvement were observed in the response variables.
