Author: Ana Cristina HolguinPublisher:
ISBN:
Category :
Languages : en
Pages : 342
Book Description
Investigation of Microflow Machining Effects on Diesel Injector Spray Characteristics
Author: Ana Cristina HolguinPublisher:
ISBN:
Category :
Languages : en
Pages : 342
Book Description
Experimental Study of Diesel Spray Characteristics and Atomization
Author: Chan-Teng ChangA Study of the Spray Characteristic for Valve Covered Orifice Diesel Nozzle Injector Using CFD
Author: Ahmad Aizuddin Faiz Che JaafarPublisher:
ISBN:
Category : Diesel fuels
Languages : en
Pages : 58
Book Description
Diesel engine performance and emissions are strongly coupled with fuel atomization and spray processes, which in turn are strongly influenced by injector flow dynamics. Modern engines employ micro-orifice with different orifice designs. It is critical to characterize the effects of various designs on engine performance and emissions. Spray characteristic of diesel fuel injection is one of the most important factors in diesel combustion and pollutant emissions where the interval between the onset of combustion and the evaporation of atomized fuel is relatively short. Therefore, this project is to study the spray simulation of diesel fuel using valve covered orifice (VCO) nozzle injector in the closed chamber. Three main components are focused on this paper, first is the relation between the spray characteristic influences of the various ambient temperature,. The second focus is the influences of the injection pressure,to the spray characteristic and the third focus is relation between the various diameter of nozzle hole size to the spray characteristic. Good spray characteristic leads to the good drivability, high combustion efficiency and stoichiometric air-fuel mixture. Therefore,Computational Fluid Dynamics (CFD) method using ANSYS Fluent simulation software is used for this purpose. The simulation of injection spray in chamber is conducted by using diesel fuel with the single and double-hole Valve Covered Orifice (VCO) nozzle, injection pressure, were various in range 5 KPa - 150 MPa, the ambient pressure, at atmosphere pressure at 101.325 Pa, the ambient temperature,was various in range of 273 K - 1000 K and at the same time iteration.
Quantification of Spray Characteristics Associated with Unique Diesel Injector Nozzles
Author: Erica Lynn BlobaumA Fundamental Investigation of Microflow and Atomisation Processes in Automotive Injectors
Author: Yong Chuan KhooPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Recent developments in automotive engines have been directed towards the reduction of engine emissions in order to minimise their effect on the environment. A major part of this advancement has been the improvement of new direct injection injectors providing improved atomisation and better control of the fuel delivery into the combustion chamber. To aid the injector design process, it is vital to understand the fundamental fluid dynamic processes controlling atomisation of high-pressure fluids in Direct Injection injectors. The research effort is directed towards the ability to link changes to the internal nozzle geometry and flow field to the external atomisation processes. This thesis presents a detailed laser diagnostic investigation of Diesel and gasoline direct injectors for automotive applications. There is a need to increase our understanding of injector flow processes occurring both internally and externally to a high-pressure fuel atomiser and the physical phenomena in generating atomised fuel in the combustion chamber. The characterisation of Diesel injector flow was achieved by the use of series of real-sized, optically accessible sapphire Diesel injectors, capable of operating at realistic driving pressures through orifice nozzles of 0.15 mm and 0.3 mm diameter. High-speed, laser-illuminated flow visualisation was used to study the effect of injector geometry on the internal flow field and the nearfield external spray structure. Data in this thesis shows that operating an injector with a counterbore provides a methodology for controlling spray angle. The study of gasoline injectors was to develop and apply innovative measurement techniques, using a series of real-sized (1 mm diameter) optical nozzles, to provide data to link the internal flow structure to the external spray development. The investigation of non-swirl flow with sharp-edged inlets nozzle showed that cavitation completely controls the flow development. Fluorescent Particle Image Velocimetry (FPIV) experiments on all chamfered inlet nozzles (30°, 45° and 60°) showed that the total velocity increased linearly with driving pressure. High-speed flow visualisation study showed that high-pressure swirl injectors generate tapered aircore in the 30° and 45° chamfered inlet orifice and parallel aircores for 60° chamfered inlet orifices. The results also showed that the film thickness was dependent of driving pressure and nozzle geometry. Application of fluorescent particle image velocimetry (FPIV) was used to provide results for internal flow velocity field for the full range of injector geometries studied. A semi-empirical relationship was used and the empirical constants was modified to fit the current experimental results. For the final optical diagnostic tool, phase Doppler anemometry (PDA) was used to provide profiles of particle size in the external spray. Examples of particle size results were shown that matched findings presented in the literature.
Analysis of Diesel Spray Characteristic at High Pressure Injection
Author: Norsyamsul Syazwan Mohd NujiPublisher:
ISBN:
Category : Diesel fuels
Languages : en
Pages : 42
Book Description
In diesel combustion, spray evaporation and mixture formation during ignition delay period play an important role in ignition, combustion and emission production. Spray evaporation begins immediately after start of fuel injection under the condition of high ambient temperature, in particular, at the middle of the spray. Spray atomization is fast promoted at this region, leading to ignition. The ambient temperature and injection pressures affect the droplets size and the number of droplets. In this project, the fuel will be injected at various injection parameters inside spray chamber in order to study the affect of that parameter towards spray characteristics. An analysis study was performed to investigate the macroscopic spray structure and the spray characteristics of high-pressure injector for the diesel engine. The spray structure and microscopic characteristics of high-pressure diesel injector were investigated when fuel was injected at various injection pressures and different nozzle diameter. Spray developing process, spray cone angle and spray tip penetration were obtained by using the software simulation of ANSYS-FLUENT, and the quantitative result of spray characteristics will be analyzes.
Annual Index/abstracts of SAE Technical Papers 2004
Author: Publisher:
ISBN: 9780768015577
Category : Automobiles
Languages : en
Pages : 962
Book Description
Spray Characteristics of Compound Silicon Micro Machined Port Fuel Injector Orifices
Author: scott E. ParrishAn Experimental Study of High Injection Pressure Diesel Sprays
Author: Tzay-Fa SuSAE 2002-30-0005, The Influence of Injector Parameters on Diesel Spray
Author: C. BaePublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Diesel injection nozzles, incorporated with common-rail, high-pressure injection system, have the variety in its geometries. The design parameters of injection nozzle need to meet the requirement of compact fuel spread and atomization followed by mixing with air and combustion in HSDI (High-Speed Direct Injection) diesel engines. Diesel injectors with various nozzle geometries were tested to investigate the spray characteristics by optical-imaging techniques. Sac-nozzle and VCO nozzle incorporated with common-rail system were tested to see the behavior of high-pressure injection. Detailed investigation into spray characteristics from the holes of VCO nozzles, mostly with double guided needle, was performed. A variety of injection hole geometries was tested and compared to give tips on better injector design. Different hole sizes and taper ratio, represented as K factor, were studied through comprehensive spray-imaging techniques. Global characteristics of non-evaporative transient diesel spray, such as spray penetration and spray angle were measured from macroscopic images, which were frozen by an instantaneous photography with spark light source and CCD camera. Internal structure during spray development for atomization was analyzed from microscopic images, which was manifested through magnified spray images taken by a long-distance microscope. These provided the better understanding of the spray surface structure and the primary breakup process of dense spray from VCO nozzles incorporated with common-rail injection system. Fuel droplet sizes, mainly represented by SMD (Sauter Mean Diameter) were also estimated from the images. Spray images were taken in a pressurized chamber (up to 30 bar) at various ambient conditions and fuel supply pressures for various nozzle geometries. The spray development from sac-nozzle and VCO nozzle was discussed. The holes with different geometry in nozzles, especially differently tapered holes (0~2 in K factor), were found to give different macroscopic behavior in terms of spray penetration and spray angle and subsequently various atomization performances. Higher K factor and smaller exit hole sizes showed faster penetration, especially at lower ambient pressure, and smaller spray angle.