The Effect of Nozzle Breakaway Pressure on the Spray Pattern Formed

2012 ◽  
Vol 248 ◽  
pp. 173-178
Author(s):  
Adedamola Najeem Peleowo
Keyword(s):  
Fuel Injection ◽  
Travel Speed ◽  
Main Function ◽  
Operating Pressure ◽  
Fuel Injector ◽  
Test Rig ◽  
Spray Pattern ◽  
Injector Nozzle ◽  
Schlieren Photography ◽  
Optical Mirrors

The main function of a fuel injector nozzle is to break fuels into droplets, form the spray pattern, and propel the droplets into a combustion chamber. The amount of spray volume at a given operating pressure, the travel speed, and spacing between the jets of fuel can also be determined by the nozzle. In fuel injection, the smallest possible droplet size is desired for the most flow. This work presents an opportunity to use the Schlieren arrangement as a visualization method to view the flow of fuel from a three-hole fuel injector nozzle which cannot be seen by the naked eye. The jet flow of diesel Fuel was investigated by Schlieren photography. A test rig was designed and constructed to accommodate the nozzle; optical mirrors were arranged according to Schlieren specifications in order to allow the jet to be photographed. The breakaway pressure of the nozzle was varied between 60bar to 80bar. Each hole of the nozzle is 0.26mm in diameter and 120° apart; the third jet could not be seen from the images because the camera took x-y dimension images. The spray pattern observed from the two dimensional images of the jets developed were seen to be well dispersed. Su et al [3] found that emissions could be reduced in diesel engines if the injector nozzle produces smaller and more dispersed droplets.

scholarly journals Modeling a fuel injector for a two-stroke diesel engine

2017 ◽  
Vol 170 (3) ◽  
pp. 147-153
Author(s):  
Rafał SOCHACZEWSKI ◽  
Zbigniew CZYŻ ◽  
Ksenia SIADKOWSKA
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Fuel Injection ◽  
Maximum Load ◽  
Fuel Injector ◽  
Dimensional Model ◽  
Flow Area ◽  
Fuel Mass ◽  
One Dimensional ◽  
Injector Nozzle

This paper discusses the modeling of a fuel injector to be applied in a two-stroke diesel engine. A one-dimensional model of a diesel injector was modeled in the AVL Hydsim. The research assumption is that the combustion chamber will be supplied with one or two spray injectors with a defined number of nozzle holes. The diameter of the nozzle holes was calculated for the defined options to provide a correct fuel amount for idling and the maximum load. There was examined the fuel mass per injection and efficient flow area. The studies enabled us to optimize the injector nozzle, given the option of fuel injection into the combustion chamber to be followed.

scholarly journals Modern Technologies for Micro-drilling of the Fuel Injector Nozzle used in Motor Vehicles - A Review of the Literature

2021 ◽  
Vol 343 ◽  
pp. 03007
Author(s):  
Dorinel Popa ◽  
Cristin-Olimpiu Morariu
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Production Capacity ◽  
Motor Vehicles ◽  
Drilling Process ◽  
Fuel Injector ◽  
Pilot Hole ◽  
Injector Nozzle ◽  
Electro Discharge Machining ◽  
Micro Drilling

To cope with the pollution norms and an improvement of the combustion of the internal combustion engines, high-quality holes with diameters smaller than 145 µm are needed for the manufacture of fuel injection nozzles. The current practice of using drilling by electro-discharge machining of fuel injection nozzles is limited in terms of the size of the hole it can efficiently produce and the time required for drilling. In addition, the cost of the tool is high. This paper presents an investigation into a sequential laser and electro-discharge micro-drilling technique for the manufacture of fuel injection nozzles. A pilot hole drilled with a laser is removed by electrodischarge. It was found that this hybrid process eliminated the problems of reformed and heat-affected areas usually associated with the laser drilling process. The new process has allowed a reduction in total drilling time compared to standard electro-discharge machining drilling, as less material is removed from the electro-discharge machining. The quality of the holes is as good as direct electro-discharge machining drilling. This technique has allowed valuable cost savings and increased production capacity for the manufacture of the fuel injector nozzle.

scholarly journals Fuel Injector Testing Through Development of a New Test Rig

2019 ◽  
Vol 8 (9) ◽  
pp. 2904-2909
Keyword(s):  
Fuel Injection ◽  
Cylinder Liner ◽  
Heating System ◽  
Injection Rate ◽  
Engine Fuel ◽  
Exhaust Manifold ◽  
Fuel Injector ◽  
Test Rig ◽  
Recirculation System ◽  
Fuel Injection Rate

A modified version of fuel injector with higher injection capacity has been developed. To achieve this, the injector plunger diameter is increased to 11mm from current 9.5mm. A new test rig is developed to understand the functioning of the injector due to the changes incorporated. The new test rig is designed to test injector operation without burning the fuel. Since internal combustion is not present an external arrangement is required to run the engine. This is achieved through a 3-phase induction motor, which is coupled with the crankshaft of the engine. The injected fuel is collected form the cylinders and it is then recirculated. A fuel cooling circuit is also incorporated along with the fuel recirculation system to maintain the temperature of fuel at inlet of fuel pump. An oil heating system is installed in the test rig to maintain the viscosity of the oil by heating it. The required systems for driving the engine, fuel cooling and oil heating are implemented as per the design. The test is conducted on a 19 L diesel engine. Parts which are not required for this test like piston, piston rings, intake and exhaust manifold etc are removed from the engine. And the cylinder liner is blocked from below using a plate to facilitate the collection of injected fuel. Engine is made to run using the motoring rig at the rated speed of 1500 rpm for a duration of 250 hours. Instrumented push tubes are used to measure the push tube load. Push tube load is observed to be in the range of 2700 to 3100 lbf, which is high as compared to the earlier model of the injector. Fuel injection rate is obtained from the fuel collected from the cylinders. And the average fuel injection rate is observed as 0.116 to 2.35 kg/min. Thus, the increase in plunger diameter has led to an increase in fuel injection rate

scholarly journals Numerical Analysis of Fuel Injector Nozzle Geometry - Influence on Liquid Fuel Contraction Coefficient and Reynolds Number

2019 ◽  
Vol 57 (1) ◽  
pp. 23-45
Author(s):  
Lino Kocijel ◽  
Vedran Mrzljak ◽  
Maida Čohodar Husić ◽  
Ahmet Čekić
Keyword(s):  
Reynolds Number ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Injection Rate ◽  
Nozzle Diameter ◽  
Nozzle Geometry ◽  
Fuel Injector ◽  
Contraction Coefficient ◽  
Nozzle Length ◽  
Injector Nozzle

This paper investigates the influence of the fuel injector nozzle geometry on the liquid fuel contraction coefficient and Reynolds number. The main three fuel injector nozzle geometry parameters: nozzle diameter (d), nozzle length (l) and nozzle inlet radius (r) have a strong influence on the liquid fuel contraction coefficient and Reynolds number. The variation of the nozzle geometry variables at different liquid fuel pressures, temperatures and injection rates was analyzed. The liquid fuel contraction coefficient and Reynolds number increase with an increase in the nozzle diameter, regardless of the fuel injection rate. An increase in the r/d ratio causes an increase in the fuel contraction coefficient, but the increase is not significant after r/d = 0.1. A nozzle length increase causes a decrease in the fuel contraction coefficient. Increase in the nozzle length of 0.5 mm causes an approximately similar decrease in the contraction coefficient at any fuel pressure and any nozzle length. Fuel injectors should operate with minimal possible nozzle lengths in order to obtain higher fuel contraction coefficients.

Calibration of Greenhouse Spray Chambers—The Importance of Dynamic Nozzle Patternation

1997 ◽  
Vol 11 (3) ◽  
pp. 428-435 ◽  
Author(s):  
Thomas M. Wolf ◽  
Shu Hua Liu ◽  
Brian C. Caldwell ◽  
Andrew I. Hsiao
Keyword(s):  
Travel Speed ◽  
Operating Pressure ◽  
Spray Pattern ◽  
Treatment Comparison ◽  
Air Turbulence ◽  
Spray Solution ◽  
End Use ◽  
Speed Effect ◽  
Volume Output ◽  
Target Plant

In an attempt to refine calibration procedures for greenhouse spray chambers, the effects of an herbicide adjuvant, operating pressure, and travel speed on the static and dynamic spray patterns of single flat-fan hydraulic nozzle tips were studied. The volume output in the central 15 cm of the spray pattern (where target plants would ordinarily be positioned) was used as an indicator of the relative dosages received from both a tapered flat-fan tip (8001 VS) and an even-spray tip (8001 EVS). All tested variables significantly altered the spray pattern. Specifically, dynamic spray patterns differed from static patterns, and speed of travel affected the dynamic pattern for both tapered and even flat-fan sprays. Increasing the travel speed from 0.375 to 0.75 m/s reduced spray deposit in the central 15 cm of the spray pattern by up to 19% for water, and by up to 34% for water containing 0.1% v/v nonionic surfactant. Increasing surfactant concentration to 1% decreased the magnitude of the speed effect. Higher pressure sprays tended to reduce the effect of increased travel speeds. These results show that changes in physicochemical properties of the spray solution as well as air turbulence introduced by nozzle movement can affect the pesticide dosage to which a target plant is exposed in a spray chamber. For proper treatment comparison, delivery systems for greenhouse spray experiments should be calibrated with end-use spray liquids, operating pressures, and nozzle travel speeds.

scholarly journals The Performance of a Reverse Flow Combustor Using JP 10 Fuel

1986 ◽  
Author(s):  
J. Winter ◽  
K. H. Maden
Keyword(s):  
Fuel Injection ◽  
Reverse Flow ◽  
Combustion Stability ◽  
Fuel Injector ◽  
Test Rig ◽  
Comparative Performance ◽  
Aviation Kerosene ◽  
Exhaust Temperature ◽  
Pure Hydrocarbon ◽  
Tube Metal

The test rig performance of a fan spray fuel injection reverse flow combustor for a 500 shp engine using JP 10 fuel is compared with that using aviation kerosene, (Avtur). JP 10 fuel is a pure hydrocarbon with a hydrogen content of 11.8% compared with some 13.8% for aviation kerosene. The comparative performance data reported include fuel injector atomisation characteristics, exhaust combustion efficiencies and emmissions, exhaust temperature distributions, flame tube metal temperatures and simulated pressure altitude relight and combustion stability over a range of conditions up to a simulated altitude of 6,1 km.

An Experimental Investigation of Combustion Chamber Design Parameters for Hot Surface Ignition

2014 ◽  
Author(s):  
Dan Chown ◽  
Charles Habbaky ◽  
James S. Wallace
Keyword(s):  
Combustion Chamber ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Design Parameters ◽  
Opening Angle ◽  
Fuel Injector ◽  
Fuel Utilization ◽  
Dominant Effect ◽  
Glow Plug ◽  
Injector Nozzle

Natural gas requires some form of ignition assist in order to autoignite in the time available in a compression ignition engine. Ignition assist using a glow plug — a heated surface — was investigated using an apparatus that consists of an optically accessible constant volume combustion bomb coupled to a single cylinder CFR engine through the spark plug port. Previous studies have shown the dominant effect of fuel injection pattern and glow plug shield geometry on ignition delay, combustion rate, and fuel utilization with 1–3 fuel jets. New work has been carried out to evaluate the ability of a shielded glow plug to ignite a full nine jet symmetrical fuel injection pattern. The sensitivity of ignition delay and fuel utilization to fuel injector angular alignment relative to the glow plug, glow plug shield opening angle, and glow plug power was analyzed using in-cylinder pressure data and exhaust hydrocarbon emissions concentrations. Two glow plugs, one conventional metallic and one ceramic, and two fuel injector nozzle orifice sizes were evaluated for their effect on ignition delay. The ignition and flame propagation process was observed using high speed images. Glow plug power was shown to have a dominant effect on ignition delay and fuel utilization, with a secondary effect from fuel injector angle and glow plug opening angle. The ceramic glow plug was shown to provide superior ignition assist while consuming less power than the metallic glow plug. The larger fuel injector nozzle size increased ignition delay times, likely due to increased convective cooling of the glow plug surface from the larger gas jet. Acquired images show that the smaller fuel injector orifice size created a flammable path in two distinct areas; along the periphery of the fuel jets and between the fuel jets. The higher mass flow rate and subsequent increased mixing of the larger fuel jets created flammable paths throughout the entirety of the combustion chamber.

Advanced Fuel Injection System Using a Supercavitating Fuel Injector

2015 ◽  
Author(s):  
John M. Gattoni ◽  
David M. Sykes ◽  
Paul E. Yelvington
Keyword(s):  
Droplet Size ◽  
High Speed ◽  
Fuel Injection ◽  
Injection System ◽  
Nozzle Geometry ◽  
Fuel Injection System ◽  
Fuel Injector ◽  
Penetration Length ◽  
Injector Nozzle ◽  
Fuel Delivery

Using the latest manufacturing technology and patented nozzle geometry, an innovative high-speed (two or more injections at an engine operating speed of 6,000 RPM), lightweight fuel injection system was developed that controls supercavitation within the fuel injector nozzle. The patented supercavitating fuel injector nozzle reduces the penetration length of the fuel spray by 25–30%, average droplet size by 15.5% when operating at the same fuel pressure, and improves droplet size uniformity over conventional nozzles. The combination of these properties represents a tremendous opportunity to improve fuel delivery in engines. In addition to the performance benefits, this technology could be easily implemented into any direct-injected engine system, both compression ignition and spark ignition engines, reciprocating and rotary, because only the nozzle assembly needs to be developed for that particular fuel injector platform.

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