Wuxi Fuel Injection Equipment Research Institute

Wuxi, China

Wuxi Fuel Injection Equipment Research Institute

Wuxi, China
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Yu S.,Jiangsu University | Yin B.,Jiangsu University | Jia H.,Jiangsu University | Yu J.,Wuxi Fuel Injection Equipment Research Institute
International Journal of Heat and Fluid Flow | Year: 2017

The Large Eddy Simulation model was introduced to study the micro spray characteristics under ultra-high injection pressure (>220 MPa). EFS8400 spray test platform was set up to verify the accuracy of the numerical model. The mechanisms of micro spray characteristics were studied intensively under different injection pressures (180 MPa, 240 MPa) and nozzle diameters (0.1 mm, 0.16 mm). The results indicated that the micro turbulence vortex structures can be captured, especially in the liquid spray core area. Large Eddy Simulation model combined with the small grid size of 0.25 mm show a huge advantage in studying the micro spray characteristics under ultra-high injection pressure; The turbulence vorticity and spray velocity for injection pressure of 240 MPa are more intensive than that of 180 MPa, and also the ultra-high injection pressure can contribute to strong turbulence disturbance between spray and surrounding air, which is helpful to improve the quality of spray; The spray velocity field extended wider for the diameter of 0.16 mm, and also the values of velocity in the spray center is higher than that of the diameter of 0.1 mm; The entrainment vortex appeared at the edge of the large velocity gradient between spray and surrounding air, and the higher velocity gradient for ultra-high injection pressure (240 MPa) between the spray and air is easier to increase the generation of entrainment vortex in the downstream of the spray, which can significantly increase the quality of spray and atomization. © 2017 Elsevier Inc.


Yao C.,Tianjin University | Hu J.,Tianjin University | Geng P.,Tianjin University | Shi J.,Tianjin University | And 2 more authors.
Fuel | Year: 2017

The experiments on the ignition and combustion characteristics of diesel in air atmosphere (AA) and premixed methanol/air mixture atmosphere (MAA) were conducted in a constant volume combustion chamber (CVCC) equipped with a high pressure common-rail injection system. The ignition and combustion processes were recorded by a high-speed camera and a combustion pressure acquisition system. Results show that with the increase of injection pressure from 40 to 160 MPa, the flame lift-off length (FLoL) becomes longer; and the ignition delay is shortened from 2.80 ms to 2.03 ms (AA) and 2.90 ms to 2.27 ms (MAA) respectively; and correspondingly the combustion duration is shortened from 5.17 ms to 2.47 ms (AA) and 4.83 ms to 2.13 ms (MAA). Compared those in AA, the ignition delay is prolonged by 0.14 ms on average, while the combustion duration is shortened by 0.27 ms in MAA. At high injection pressure, the moments that the maximum combustion pressure occurs and the apparent heat release rates (AHRR) starts to rise are advanced; while in MAA both of them are delayed; and the peak value of AHRR increases. With the increase of injection pressure, both spatially integrated natural luminosity (SINL) and time integrated natural luminosity (TINL) reduce significantly, but the reduction trends of TINL weaken. Due to the addition of methanol, the FLoL of diesel becomes longer, and the SINL and TINL in MAA are both lower than those in AA. © 2017 Elsevier Ltd


Bai F.,Tianjin University | Chang Q.,Tianjin University | Chang Q.,Wuxi Fuel Injection Equipment Research Institute | Guo J.,Tianjin University | Du Q.,Tianjin University
Neiranji Xuebao/Transactions of CSICE (Chinese Society for Internal Combustion Engines) | Year: 2017

The temporal instability of a two-dimensional power law liquid sheet moving in a static inviscid gas medium was investigated theoretically. There were two kinds of disturbance modes for the sheet: varicose mode and sinuous mode. The corresponding dispersion relation between the growth rate and the wave number of disturbed interface waves for each mode was derived with a linear approximation. By solving the dispersion equations numerically, the effects of the generalized Reynolds number, the Weber number, the density ratio of gas to liquid and the power law exponent, on the instability of the sheet were studied. The results reveal that, for both the modes and for both the shearthinning and shear-thickening fluids, the viscosity and surface tension of the liquid prevent the sheet from breaking up while the aerodynamic interaction between the gas and the liquid promotes the breakup process. And a liquid sheet with a smaller power law exponent is easier to disintegrate. Moreover, although sinuous disturbances always dominate the instability process of the sheet, varicose disturbances also play an important role, especially when the maximum growth rate of varicose mode is the same order as that of sinuous mode. © 2017, Editorial Office of the Transaction of CSICE. All right reserved.


Yu S.,Jiangsu University | Yin B.,Jiangsu University | Jia H.,Jiangsu University | Wen S.,Jiangsu University | And 2 more authors.
Fuel | Year: 2017

The internal flow in nozzle and macroscopic spray characteristics of diesel and biodiesel, by employing a validated numerical model and a laser-based Mie-scattering technique, are investigated. The results indicate that both the mass flow rate and the orifice exit average velocity of diesel are larger than those of biodiesel. Also, that diesel consistently produced higher cavitation intensity and turbulence kinetic energy confirms diesel can boost the naissance of cavitation and the turbulence disturbance inside the nozzle. Meanwhile, the cavitation intensity and the turbulence kinetic energy increase dramatically as the injection pressure increases; the cavitation domain is consistent with the domain of high turbulence kinetic energy. Furthermore, the radial velocity of diesel is significantly higher than biodiesel under the same injection pressure, while the radial velocities of both fuels increase as the injection pressure increase. Moreover, the spray tip penetration of biodiesel is longer than that of diesel, while the aerodynamic spray cone angle of biodiesel is narrower that of diesel under the same injection pressure. Higher surface tension and viscosity of biodiesel resulted in smaller cavitation intensity, turbulence kinetic energy and radial velocity at the nozzle exit, which in turn contribute to the narrowing of the aerodynamic spray cone angle. © 2017 Elsevier Ltd


Zhang G.,Shanghai JiaoTong University | Qiao X.,Shanghai JiaoTong University | Miao X.,Wuxi Fuel Injection Equipment Research Institute | Hong J.,Wuxi Fuel Injection Equipment Research Institute | Zheng J.,Wuxi Fuel Injection Equipment Research Institute
Fuel | Year: 2012

The fuel injection rate profile and spray characteristics of both the highly dispersed spray nozzle and the conventional nozzle have been studied through experiments. The experimental results indicate that the highly-dispersed nozzle has a higher fuel injection rate, shorter injection duration, shorter spray tip penetration, fatter spray cone angle, smaller spray projected area and larger spray volume than the conventional nozzle. According to the original experimental results and the fluid collision and breakup theories, the SMD of the highly-dispersed nozzle is smaller than that of the conventional nozzle. Additionally, the combustion and emission characteristics of a heavy-duty diesel engine when equipped with the highly-dispersed nozzle and the conventional nozzle respectively have been studied through experiments. The experimental results indicate the tested engine equipped with highly-dispersed nozzles has a lower emission level and better BSFC performance than that equipped with conventional nozzles. All these validate that compared with the conventional nozzle, the highly-dispersed nozzle can shorten the fuel injection duration to save time for the fuelair mixing, promote the fuelair mixing and improve the fuel atomization, which are beneficial to the formation of homogeneous mixture. © 2012 Elsevier Ltd. All rights reserved.


Zhang G.,Shanghai JiaoTong University | Qiao X.,Shanghai JiaoTong University | Miao X.,Wuxi Fuel Injection Equipment Research Institute | Hong J.,Wuxi Fuel Injection Equipment Research Institute | And 2 more authors.
Applied Thermal Engineering | Year: 2012

The work aims not only to exploit the petroleum alternative fuel for relieving the energy crisis, but also to realize the ultra-low emissions of diesel engines fueled with this alternative fuel. The effects of direct coal liquefaction (DCL) on combustion and emissions have been studied in a heavy-duty engine fueled with exhaust gas recirculation (EGR). Two cases of the diesel engine operating condition were studied: 1000 r/min, 110 N m (referred to as Case A) and 1400 r/min, 473 N m (referred to as Case B). The experimental results showed that with the increase of EGR, the maximum in-cylinder pressure, rate of heat release and mean gas temperature decrease; the brake fuel conversion efficiency (BFCE) first increases slightly then decreases; brake specific fuel consumption (BSFC) has the opposite variation trend to BFCE. As the increase of EGR, the nitrogen oxides (NOx) emissions decrease monotonically, the soot emissions increase slightly, the hydrocarbon (HC) and carbon monoxide (CO) emissions increase, and the carbon dioxide (CO 2) and oxygen (O 2) concentration of the exhaust products increases and decreases respectively. The trade-off relationship between NOx and soot emissions can be improved when diesel engines are fueled with DCL instead of diesel. © 2011 Elsevier Ltd. All rights reserved.


Zheng J.-B.,Wuxi Fuel Injection Equipment Research Institute | Miao X.-L.,Wuxi Fuel Injection Equipment Research Institute | Wang X.-Y.,Wuxi Fuel Injection Equipment Research Institute | Hong J.-H.,Wuxi Fuel Injection Equipment Research Institute | Chen X.-Y.,Wuxi Fuel Injection Equipment Research Institute
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2011

On engine test bench, cycle-by-cycle variations of premixed combustion diesel engine in low and medium load conditions were experimentally studied. The effects of EGR, injection timing and injection pressure on the cycle-by-cycle variations were examined. The results show that the engine has shorter combustion duration, quicker heat release and higher pressure rise rate in premixed combustion mode. With EGR rate increasing and injection timing retarding, the maximum combustion pressure and maximum pressure rise rate lower. The cycle-by-cycle variation coefficient of the maximum pressure rise rate increases with the increase of EGR rate and decreases with injection timing retarding. There exists a strong correlation between the early combustion stage and subsequent combustion parameters. At the condition points of smaller cycle-by-cycle variations, the emissions are lower too. The effects of EGR rate, injection timing etc. on the cycle-by-cycle variation coefficients can be expressed well by air fuel ratio. At normal condition the cycle-by-cycle variation coefficient of mean indicated pressure is always below 10%. Some measures to minimize the cycle-by-cycle variations were put forward for less emissions.


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.


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.


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.

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