Visual experimental investigations of string cavitation and residual bubbles in the diesel nozzle and effects on initial spray structures

2018 ◽  
Vol 21 (3) ◽  
pp. 437-447 ◽  
Author(s):  
Genmiao Guo ◽  
Zhixia He ◽  
Zhengyang Zhang ◽  
Lian Duan ◽  
Wei Guan ◽  
...  
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Fuel Mixture ◽  
Injection System ◽  
Experimental Investigations ◽  
Spray Cone ◽  
Nozzle Orifice ◽  
Diesel Nozzle ◽  
Initial Fuel ◽  
Opening And Closing

In this article, optical experiments on string cavitation and residual bubbles inside the real-size transparent tapered diesel nozzle and near-nozzle spray structures were performed based on a high-pressure common rail fuel injection system with a high-speed camera. The tapered nozzle which has high flow efficiency with weak or even no geometric cavitation has been widely used in commercial injectors, while there still exists string cavitation which may also influence the in-nozzle flow and subsequent spray. This article put focus on the tapered nozzle and the result indicated that the in-nozzle string cavitation provided a reasonable explanation for the two bumps of spray cone angles during the opening and closing stages of needle of real diesel engine injection processes. The suction and compression of air bubbles at the start and end stages of injection processes, and the various shot-to-shot near-nozzle spray patterns were captured and analyzed. These different near-nozzle spray patterns were attributed to the distribution of residual bubbles inside the nozzle orifice. The residual bubbles were survived from the last injection or sucked into the nozzle during needle opening stages. Stagnant bubbles were compressed and then accelerated the residual fuel which was close to the injector tip, leading to the formation of mushrooms. This study confirmed that the initial mushroom and the tail were generated by the interactions between the residual/sucked bubbles and the residual/initial fuel, and the leading mushroom was incurred by the combination of the transverse expansion of the jet and the laminar layer theory. This work pointed out and analyzed the new sources of the cycle-to-cycle variation of air/fuel mixture and spray.

scholarly journals Spray Characteristics at Preheating Temperatur of Diesel-Biodiesel-Gasoline Fuel Blend

2021 ◽  
Vol 5 (2) ◽  
pp. 134
Author(s):  
Moch Miftahul Arifin ◽  
Nasrul Ilminnafik ◽  
Muh. Nurkoyim Kustanto ◽  
Agus Triono
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Fuel Injection ◽  
Fuel Mixture ◽  
Spray Angle ◽  
Injection System ◽  
Spray Characteristics ◽  
Fuel Blend ◽  
Spray Tip Penetration

Technological developments in diesel engines require improvements to the fuel injection system to meet the criteria for economical, high-power and efficient combustion and meet environmental regulatory standards. One method that has a lot of interest is changing the characteristics of the fuel, with the aim of producing optimal combustion. Spray characteristics have a big role in determining the quality of combustion in diesel engines. A good spray can improve the quality of fuel atomization and the homogeneity of the air-fuel mixture in the combustion chamber so that it can produce good engine performance and low emissions. This study aims to determine the effect of a diesel-biodiesel (Calophyllum inophyllum)-gasoline blendandfuel heating on the spray characteristics. The research was conducted with variations in composition (B0, B100, B30, B30G5 and B30G10) and fuel heating (40, 60, 80, and 100 °C). Fuel injected atapressure of 17 MPa in to a pressure chamber of 3 bar. The spray formed was recorded with a high-speed camera of 480 fps (resolution 224x168 pixel). In B100 biodiesel, the highest viscosity and density cause high spray tip penetration, small spray angle, and high spray velocity. The addition of diesel oil, gasoline, and heating fuel reduces the viscosity and density so that the spray tip penetration decreases, the spray angle increases and the velocity of spray decreases.

Fuel Injection System for a High Speed One Cylinder S.I.Engine

2001 ◽  
Author(s):  
Göran Almkvist ◽  
Tomas Karlsson ◽  
Styrbjörn Gren ◽  
Jörgen Bengtsson ◽  
Conny Andersson ◽  
...  
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System

Some Problems Connected with High-Speed Compression-Ignition Engine Development

1932 ◽  
Vol 36 (261) ◽  
pp. 733-787 ◽  
Author(s):  
C. B. Dicksee
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Development

In this paper the author does not propose to deal with any particular form or type of engine or fuel-injection system, but to discuss some of the problems which are encountered when engaged on the development of a high-speed compression-ignition engine.The main problems to be solved consist in devising suitable means for utilising to the fullest possible extent the oxygen available within the cylinder and for avoiding the production of smoke and noise and, in so far as it is connected with combustion conditions, smell.

scholarly journals Research on combustion process of gasoline homogenous charge compression ignition engine

2018 ◽  
Vol 184 ◽  
pp. 01013
Author(s):  
Corneliu Cofaru ◽  
Mihaela Virginia Popescu
Keyword(s):  
Experimental Research ◽  
Fuel Injection ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Spark Ignition Engine ◽  
Injection System ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Operation ◽  
Homogenous Charge Compression Ignition

The paper presents the research designed to develop a HCCI (Homogenous Charge Compression Ignition) engine starting from a spark ignition engine platform. The chosen test engine was a single cylinder, four strokes provided with a carburettor. The results of experimental research data obtained on this version were used as a baseline for the next phase of the research. In order to obtain the HCCI configuration, the engine was modified, as follows: the compression ratio was increased from 9.7 to 11.5 to ensure that the air – fuel mixture auto-ignite and to improve the engine efficiency; the carburettor was replaced by a direct fuel injection system in order to control precisely the fuel mass per cycle taking into account the measured intake air-mass; the valves shape were modified to provide a safety engine operation by ensuring the provision of sufficient clearance beetween the valve and the piston; the exchange gas system was changed from fixed timing to variable valve timing to have the possibilities of modification of quantities of trapped burnt gases. The cylinder processes were simulated on virtual model. The experimental research works were focused on determining the parameters which control the combustion timing of HCCI engine to obtain the best energetic and ecologic parameters.

A High-Speed Direct Injection Diesel Engine for Passenger Cars

1988 ◽  
Vol 202 (3) ◽  
pp. 171-181 ◽  
Author(s):  
J A Stephenson ◽  
B A Hood
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Passenger Cars ◽  
Medium Speed ◽  
Medium Speed Engine ◽  
Hsdi Diesel Engine ◽  
Wide Speed Range

The paper describes the development of a high-speed direct injection (HSDI) diesel engine suitable for passenger car applications. The evolution from a low emissions medium-speed engine, through a four-cylinder 2.3 litre research engine, into a four-cylinder 2.0 litre production engine is presented. The challenge to the engineer has been to develop the HSDI engine to operate with acceptable noise, emissions, smoke and driveability over the wide speed range (up to 5000 r/min) required for passenger cars. The key element in this task was the optimization of the combustion system and fuel injection equipment. The HSDI is shown to have a significant fuel economy advantage over the prechamber indirect injection (IDI) engine. Future developments of the fuel injection system are described which will further enhance the HSDI engine and provide additional noise and emissions control.

Diagnosis of Faults in the Fuel Injection System of a Forging Machine Using Fuzzy Sets Theory

1994 ◽  
Vol 208 (2) ◽  
pp. 123-129
Author(s):  
D T Pham ◽  
M H Wu
Keyword(s):  
Fuzzy Sets ◽  
High Speed ◽  
Fuel Injection ◽  
Diagnostic System ◽  
Diagnostic Methods ◽  
Injection System ◽  
Fuzzy Sets Theory ◽  
Membership Functions ◽  
Sets Theory ◽  
Types Of Faults

This paper describes a diagnostic system for the fuel injection module in a high-speed forging machine. The system is based on the use of fuzzy sets techniques, with a fuzzy set representing each fault in the module. Empirical membership functions for the different fuzzy sets are employed to locate faults according to conditions observed on the forging machine. Two types of faults can be handled: faults due to one of more valves in the fuel injection module remaining in their unenergized state and faults caused by a valve being stuck in the energized state. Details of the diagnostic methods for both fault types are presented following a brief review of the operating principle of the forging machine.

Direct Water Injection to Improve Diesel Spray Combustion

2003 ◽  
Author(s):  
Koji Takasaki ◽  
Tatsuo Takaishi ◽  
Hiroyuki Ishida ◽  
Keijirou Tayama
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Fuel Injection ◽  
Nox Reduction ◽  
Water Injection ◽  
Injection Pressure ◽  
Injection System ◽  
Injection Hole ◽  
Low Speed ◽  
Direct Water Injection

Now, it is essential to apply some measures for NOx reduction to low-speed diesel engines emitting much more NOx than high-speed engines. At the same time PM emission must be reduced especially when bunker fuel or heavy fuel is burned. This paper describes the applications of SFWI (Stratified Fuel Water Injection) system and DWI (Direct Water Injection) system to large sized diesel engines to reduce NOx and PM emission. SFWI system makes it possible to inject water during fuel injection from the same nozzle hole without mixing the liquids. DWI system injects water with high injection pressure from the other injection hole than the fuel injection hole into the combustion chamber directly. For testing both the systems, a 2-stroke-cycle low-speed test engine was used.

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