Time filter

Source Type

Yin B.,Jiangsu University | Yu S.,Jiangsu University | Jia H.,Jiangsu University | Yu J.,Wuxi Fuel Injection Equipment Research Institute
International Journal of Heat and Fluid Flow | Year: 2016

A special spray model is applied to study the spray behavior with high injection pressure and micro-hole nozzle. To reveal the cavitation in diesel nozzle and its influence on spray and atomization, the Large Eddy Simulation (LES) turbulence model is adopted to detect the cavitation, and then the special spray model coupling the cavitation is build. From research results, three important conclusions can be drawn. Firstly, the cavitation flow can raise the effective velocity at the nozzle exit and such effect become even more obvious with higher injection pressure, e.g.180. MPa. Secondly, the applied spray model is in good agreement with the spray characteristics and images obtained from the EFS8400 spray test platform. Thirdly, the cavitation with high injection pressure and micro-hole nozzle can increase the spray cone angle and reduce the spray penetration; the cavitation intensity has a great impact on the spray velocity field and vorticity intensity, especially at the initial spray field under the condition of high injection pressure. © 2016 Elsevier Inc.

Li P.,Beijing Institute of Technology | Zhang Y.,Beijing Institute of Technology | Xie L.,Beijing Institute of Technology | Hu L.,Wuxi Fuel Injection Equipment Research Institute
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2014

Oil pressure fluctuation caused by last injection can lead to oil mass deviation of this injection during multi-injection of high pressure common-rail system. Influence of rail pressure on the oil mass deviation amplitude of the second injection under two different injection pulse width of the first injection is researched. The results show that the changing of oil mass deviation amplitude with rail pressure shows different law under different injection pulse width of the first injection. The influence of rail pressure on the amplitude of pressure fluctuation caused by a single injection is also studied under two different injection pulse width. The results show that the influences of rail pressure on the oil mass deviation amplitude and pressure fluctuation amplitude are almost the same when the injection pulse width is small, but there is a difference when the injection pulse width is large. Mechanism of the influences of rail pressure on oil mass deviation amplitude is discussed in detail. A coefficient named injection time deviation coefficient which demonstrates the mechanism of the influence of rail pressure on oil mass deviation is put forward. The influence law of rail pressure on oil mass deviation amplitude is acquired. © 2014 Journal of Mechanical Engineering.

Fan B.,Jiangsu University | Pan J.,Jiangsu University | Huang J.,Wuxi Fuel Injection Equipment Research Institute | Xiao M.,Jiangsu University | Yao J.,Jiangsu University
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2015

Taking a side ported pre-mixed natural gas-fueled rotary engine converted from a gasoline rotary engine as the study object. On the basis of the Fluent simulation software, a three-dimensional dynamic simulation model is established by writing dynamic mesh programs and choosing the reasonable turbulent model, combustion model, CHEMKIN mechanism. The three-dimensional dynamic simulation model based on the chemical reaction kinetics is also validated by the experimental data. On this basis, the three-dimensional dynamic characteristics for flow, temperature field and the combustion intermediate product under different combustion chamber configuration are analyzed. The results show that when the rotor pocket is located at the front end of rotor surface along length direction and the center of the rotor surface along width direction, a tumble in the rear of combustion chamber and a high speed flow in the middle of combustion chamber are made full use to increase flame speed. The flame propagation speed reaches the maximum value. The indicator diagram is best and the production of OH is biggest. Comparing with mid pocket combustion chamber, the front pocket combustion chamber shows a 19.9 percent increase in the peak pressures, but NO emission mass fraction still stay within 0.5 percent. © 2015 Journal of Mechanical Engineering.

Zhu J.-M.,Wuxi Fuel Injection Equipment Research Institute | Peng D.-Y.,Wuxi Fuel Injection Equipment Research Institute
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2011

The current world oil situation and various new-energy concepts were analyzed, and a new-energy development strategy for China was put forward. At present stage China must continue utilizing conventional energy more rationally and efficiently, meantime explore emphatically practical and effective new-energy resources, particularly realize their industrialization. If China launches development of new energy rashly and disorderly, neglecting the conventional energy technology improvements, it may fall into a bottomless pit of money and efforts, and waste the accumulated achievements in automobile and internal combustion engine industries for many years, thus being behind the developed countries once more.

Yao C.,Tianjin University | Geng P.,Tianjin University | Yin Z.,Tianjin University | Hu J.,Tianjin University | And 2 more authors.
Fuel | Year: 2016

Diesel engine performance and emissions are closely related to fuel atomization and spray processes, which in turn are strongly influenced by nozzle geometry. In this study, five kinds of single-hole cylindrical injectors which have different orifice diameters (0.13-0.23 mm) and lengths (0.7-1.0 mm) were employed to research the effects of the nozzle geometry on spray droplet size distribution and corresponding combustion characteristics. The spray droplet size spatial distribution was measured with the Phase Doppler Particle Analyzer (PDPA). The results show that the Sauter Mean Diameter (SMD) reduces with the increase of the distance from injector tip and the SMD of the central axis is bigger than that of the periphery. With the increase of the injection pressure (40-120 MPa), the spray SMD decreases significantly. In addition, as the orifice diameter goes smaller, the SMD decreases and the effect of the orifice diameter on the spray SMD becomes weak. Meanwhile, as the orifice length goes longer, the SMD decreases when the orifice diameter is 0.13 mm. And then, the combustion characteristics were experimentally investigated in a constant volume chamber with optical access. Time-resolved images of the natural luminosities (indicator of soot) from the combustion process were captured by high speed camera and combustion pressure was also acquired. It is found that there is a good corresponding relationship between spray SMD, combustion heat release rate and flame luminosity. That is to say, the way to decrease SMD reduces greatly the natural luminosities and improves combustion heat release rate. This article presents the effects of nozzle geometry on droplet size distribution and combustion, and provides important references for injector manufacture. © 2016 Elsevier Ltd. All rights reserved.

Discover hidden collaborations