Computational Study on the Effect of Local Expansion and Contraction Upon Surface Deposition in a Heated Fuel Injector

2011 ◽  
Author(s):  
Ehsan Alborzi ◽  
Renato Piazzolla ◽  
Christopher Wilson
Keyword(s):  
Fuel Injection ◽  
Computational Study ◽  
Fluid Dynamic ◽  
Jet Fuel ◽  
Injection System ◽  
Data Sampling ◽  
Fuel Injector ◽  
Chemical Kinetic Model ◽  
Surface Deposition ◽  
Local Expansion

A preliminary numerical analysis was carried out to examine the effect of local expansion and contraction on surface deposition rate for two series of geometries. These geometries correspond to the new geometrical features found in jet fuel injection system. For this simulation, commercial computational fluid dynamic package, Fluent 6.3.26, was used. Fluid flow, energy, and turbulence equations were solved coupled with a pseudo-detailed chemical kinetic model for jet fuel thermal degradation and the subsequent surface deposition sub model. The model results indicate that the highest deposition rates occur at intermediate expansion ratios and for a bigger inlet diameter due to a lower convective heat transfer. It was also shown that high expansion ratios are recommended to be used for short injector lengths. These simulated results are used for the experimental work in progress. The most susceptible locations to surface deposition are those with the highest rates; these are the best indicative points for data sampling.

scholarly journals Diagnostics of common rail components based on pressure curves in the fuel rail

2018 ◽  
Vol 173 (2) ◽  
pp. 3-8
Author(s):  
Mirosław KARCZEWSKI ◽  
Krzysztof KOLIŃSKI
Keyword(s):  
High Pressure ◽  
Fuel Injection ◽  
Dynamic Pressure ◽  
Common Rail ◽  
Injection System ◽  
Fuel Injector ◽  
Labview Software ◽  
Cr System ◽  
Data Acquisition Module ◽  
Pressure Changes

Majority of modern diesel engines is fitted with common-rail (CR) fuel systems. In these systems, the injectors are supplied with fuel under high pressure from the fuel rail (accumulator). Dynamic changes of pressure in the fuel rail are caused by the phenomena occurring during the fuel injection into the cylinders and the fuel supply to the fuel rail through the high-pressure fuel pump. Any change in this process results in a change in the course of pressure in the fuel rail, which, upon mathematical processing of the fuel pressure signal, allows identification of the malfunction of the pump and the injectors. The paper presents a methodology of diagnosing of CR fuel injection system components based on the analysis of dynamic pressure changes in the fuel rail. In the performed investigations, the authors utilized LabView software and a µDAC data acquisition module recording the fuel pressure in the rail, the fuel injector control current and the signal from the camshaft position sensor. For the analysis of the obtained results, ‘FFT’ and ‘STFT’ were developed in order to detect inoperative injectors based on the curves of pressure in the fuel rail. The performed validation tests have confirmed the possibility of identification of malfunctions in the CR system based on the pressure curves in the fuel rail. The ‘FFT’ method provides more information related to the system itself and accurately shows the structure of the signal, while the ’STFT’ method presents the signal in such a way as to clearly identify the occurrence of the fuel injection. The advantage of the above methods is the accessibility to diagnostic parameters and their non-invasive nature.

Combining Instantaneous Temperature Measurements and CFD for Analysis of Fuel Impingement on the DISI Engine Piston Top

2009 ◽  
Author(s):  
Kukwon Cho ◽  
Ronald O. Grover ◽  
Dennis Assanis ◽  
Zoran Filipi ◽  
Gerald Szekely ◽  
...  
Keyword(s):  
Film Thickness ◽  
Heat Loss ◽  
Cfd Simulation ◽  
Computational Study ◽  
Fluid Dynamic ◽  
Direct Injection ◽  
Negative Temperature ◽  
Fuel Injector ◽  
Fuel Film ◽  
Film Evaporation

A two-pronged experimental and computational study was conducted to explore the formation, transport, and vaporization of a wall film located on the piston surface within a four-valve, pent roof, direct-injection spark-ignition (DISI) engine, with the fuel injector located between the two intake valves. Negative temperature swings were observed at three piston locations during early injection, thus confirming the ability of fast-response thermocouples to capture the effects of impingement and heat loss associated with fuel film evaporation. Computational Fluid Dynamic (CFD) simulation results demonstrated that the fuel film evaporation process is extremely fast under conditions present during intake. Hence, the heat loss measured on the surface can be directly tied to the heating of the fuel film and its complete evaporation, with the wetted area estimated based on CFD predictions. This finding is critical for estimating the local fuel film thickness from measured heat loss. The simulated fuel film thickness and transport corroborated well temporally and spatially with measurements at thermocouple locations directly in the path of the spray, thus validating the spray and impingement models. Under the strategies tested, up to 23% of fuel injected impinges upon the piston and creates a fuel film with thickness of up to 1.2 μm. In summary, the study demonstrates the usefulness of heat flux measurements to quantitatively characterize the fuel film on the piston top and allows for validation of the CFD code.

Development of Fuel Injector Monitoring Using Strain Gauge Signal

2014 ◽  
Vol 663 ◽  
pp. 426-430
Author(s):  
C.L. Hoo ◽  
Mohd Zaki Nuawi ◽  
S.M. Haris ◽  
S. Abdullah ◽  
Ahmad Rasdan Ismail
Keyword(s):  
Strain Gauge ◽  
Pulse Width ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injector ◽  
Engine Operation ◽  
Monitoring Task ◽  
Vehicle Engine ◽  
Actual Operation ◽  
Pressure Bar

The Fuel injector is an important component in a vehicle engine for determining the performance of an engine. It is believed that, by knowing the current state of the injector, one can take any prior safety measure and ensuring the optimal performance of the engine. However, it is very difficult to study and analyse the fuel injection system in real time during the operation of the vehicle. A study was conducted in developing a method to monitor the fuel injector using the strain signal generated from the strain gauge sensors installed on the fuel injector. This method is practically implementable and can be used on the actual operation of the engine. A research rig was developed in order to visualise the behaviour of the injector at any instant by obtaining the three key parameters from the strain gage sensors which are the pulse width (ms), frequency (Hz) and pressure (bar). All data obtained from this experiment will be analysed using the Matlab software, where the I-kaz (Z∞) will be applied as the main method to clearly visualize the operation of the machine. The result shows that for the same pulse width and pressure, the series have the same pattern for I-kaz coefficient. They have a consistent trend compared to the Skewness and Kurtosis parameters. This method serves to predict and describe the behaviour of the fuel injector to ease the monitoring task at any instant throughout the engine operation.

Reduction of Nitric Oxide Emission From a SI Engine by Water Injection at the Intake Runner

2009 ◽  
Author(s):  
Jun-Kai Wang ◽  
Jing-Lun Li ◽  
Ming-Hsun Wu ◽  
Rong-Horng Chen
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Effective Means ◽  
Water Injection ◽  
Nox Emission ◽  
Injection System ◽  
Hydrocarbon Emissions ◽  
Fuel Injector ◽  
Unburned Hydrocarbon ◽  
Nitric Oxide Emission

The effects of pulsed water injection at the intake port of a modern port fuel injection gasoline engine were investigated. A port water injection system was developed and the water injector was installed on the intake runner of the single cylinder motorcycle engine at a location upstream of the fuel injector. The results show that with a water-gasoline injection ratio of 1, more than 80% of NOx emission can be removed. The trade-off was a 25% reduction in torque output at 4000 rpm and 20% throttle opening; however, the decrease on torque can be controlled to be within 5% by reducing water-gasoline mass ratios to less than 0.6. We also performed NOx emission modeling using one-dimensional gas dynamics code with extended Zeldovich mechanism, and consistent results were found between numerical prediction and experimental measurements. The port water injection approach appears to be an effective means for reducing NOx emission from a gasoline engine at low speed and high load conditions without largely sacrificing the performances on torque output and unburned hydrocarbon emissions.

Development of Fuel Injector and Fuel Pump for a Fuel Injection System to Use in Small Motorcycles

2005 ◽  
Author(s):  
Tatsuya Ujiie ◽  
Hidetoshi Saito ◽  
Minoru Ueda ◽  
Shunji Akamatsu ◽  
Akira Hayashi ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System ◽  
Fuel Injector ◽  
Fuel Pump

Numerical Simulation of the Dynamic Response of a Diesel Fuel Injector Using CFD

2005 ◽  
Author(s):  
Yong Yi ◽  
Aleksandra Egelja ◽  
Clement J. Sung
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Dynamic Response ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System ◽  
Fuel Injector ◽  
Diesel Fuel Injection ◽  
Very High

The development of a very high pressure diesel fuel injection system has been one of the key solutions to improve engine performance and to reduce emissions. The diesel fuel management in the injector directly affects how the fuel spray is delivered to the combustion chamber, and therefore affects the mixing, combustion and the pollutants formation. To design such a very high pressure diesel fuel injection system, an advanced CFD tool to predict the complex flow in the fuel injection system is required in the robust design process. In this paper, a novel 3D CFD dynamic mesh with cavitation model is developed to simulate the dynamic response of the needle motion of a diesel fuel injector corresponding to high common rail pressure and other dimensional design variables, coupling with the imbalance of the spring force and the flow force (pressure plus viscous force). A mixture model is used for cavitation resulting from high speed flow in fuel injector. Due to the lack of experimental data, the model presented in this paper is only validated by a limited set of experimental data. Required meshing strategy is also discussed in the paper.

Single Cylinder Testing of a High-Pressure Electronic Pilot Fuel Injector for Low NOx Emission Dual Fuel Engines: Part I—Baseline, Feasibility, and Comparative Testing

1990 ◽  
Vol 112 (3) ◽  
pp. 413-421 ◽  
Author(s):  
J. Workman ◽  
G. M. Beshouri
Keyword(s):  
Fuel Injection ◽  
Waste Water Treatment ◽  
Injection System ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Current Minimum ◽  
Feasibility Test

Current dual fuel engines utilizing standard mechanical (Bosch type) fuel injection systems set to 5–6 percent pilot delivery do not appear capable of reducing NOx emissions much below the current minimum of 4 g/bhp-h without incurring substantial penalties in efficiency and operability. A prototype Electronic Pilot Fuel Injector (EPFI) was designed that overcomes the shortcomings of the mechanical injection system, consistently delivering 3 percent or less pilot at pressures as high as 20,000 psi. The EPFI was installed and tested in one cylinder of a standard production dual fuel engine operating at a waste water treatment facility. A feasibility test confirmed that the engine would indeed operate satisfactorily at 2.9 percent pilot. Comparisons with baseline data revealed the EPFI yielded a 45 percent reduction in NOx emissions with a 3 percent or greater improvement in efficiency. Further optimization of the system, discussed in Part II, indicates that even greater reductions in NOx emissions can be obtained without incurring a penalty in fuel consumption.

A Simulation Study of Magnetostrictive Material Terfenol-D in Automotive CNG Fuel Injection Actuation

2009 ◽  
Vol 154 ◽  
pp. 41-46 ◽  
Author(s):  
H.A. Chowdhury ◽  
Saiful Amri Mazlan ◽  
Abdul Ghani Olabi
Keyword(s):  
Flow Rate ◽  
Fuel Injection ◽  
Response Times ◽  
Turbulence Models ◽  
High Energy ◽  
Injection System ◽  
Fuel Injector ◽  
Cross Sectional ◽  
Magnetostrictive Material ◽  
Fast Control

Magnetostriction is the deformation that spontaneously occurs in ferromagnetic materials when an external magnetic field is applied. In applications broadly defined for actuation, magnetostrictive material Terfenol-D (Tb0.3Dy0.7Fe1.9) possesses intrinsic rapid response times while providing small and accurate displacements and high-energy efficiency. These are some of the essential parameters required for fast control of fuel injector valves for decreased engine emissions and lower fuel consumption compared with the traditional solenoid fuel injection system. A prototype CNG fuel injector assembly was designed which included magnetostrictive material Terfenol-D as the actuator material. A 2D cross-sectional geometry of the injector assembly, which incorporated both linear and non-linear magnetic properties of the corresponding materials, was modeled in ANSYS for 2D axisymmetric magnetic simulation. Subsequently, a 3D replica of the CNG flow conduit was modeled in GAMBIT with the resultant injector lift. The meshed conduit was then simulated in FLUENT using the 3D time independent segregated solver with the Standard k  , the Realizable k   and RSM turbulence models to predict the mass flow rate of CNG to be injected. Eventually, the simulated flow rate was verified against mathematically derived static flow rate required for a standard automotive fuel injector considering standard horsepower, BSFC and injector duty cycle.

Flow and Spray Characteristics of a Lean Fuel Injection Module With Radial Swirlers

2000 ◽  
Author(s):  
Woo Seok Seol ◽  
Yeoung Min Han ◽  
Dae Sung Lee
Keyword(s):  
Fuel Injection ◽  
Reverse Flow ◽  
Jet Fuel ◽  
Fuel Injector ◽  
Flow Zone ◽  
Mixing Rate ◽  
Spray Characteristics ◽  
Injection Point ◽  
Size Number ◽  
Lean Fuel

Lean fuel modules are sometimes employed to reduce NOx emissions in aero-engine combustors. With a lean fuel module whose AFR is larger than the stoichiometric AFR, the bulk AFR remains larger than the stoichiometric AFR throughout the combustor, and hence the peak NOx producing regime can be avoided. In addition, by introducing a large amount of air at the fuel injection point and increasing the mixing rate, the existing time of local stoichiometric pockets can be reduced. In the present study, flow and spray characteristics of a 21AFR lean fuel module, which consists of a pressure jet fuel injector and radial air swirlers, are measured by an adaptive Phase/Doppler technique. Gas phase velocity field, and distributions of droplet size, number density, and liquid phase volume flux are presented for co-swirl and counter-swirl lean modules. The present study reveals that a strong reverse flow zone is formed by the lean fuel module with radial swirlers. The shape of the reverse flow zone and the reverse flow velocity depend on the swirl direction significantly. The lean fuel module with radial swirlers provides effective atomization, and the SMD distribution near the module exit is quite uniform. The swirl direction has significant effects on the spray characteristics, too.

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