scholarly journals Approaches for Detailed Investigations on Transient Flow and Spray Characteristics during High Pressure Fuel Injection

2020 ◽  
Vol 10 (12) ◽  
pp. 4410 ◽  
Author(s):  
Noritsune Kawaharada ◽  
Lennart Thimm ◽  
Toni Dageförde ◽  
Karsten Gröger ◽  
Hauke Hansen ◽  
...  
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Transient Flow ◽  
Numerical Models ◽  
Near Field ◽  
Transient Nature ◽  
Injector Nozzle ◽  
Considerable Impact

High pressure injection systems have essential roles in realizing highly controllable fuel injections in internal combustion engines. The primary atomization processes in the near field of the spray, and even inside the injector, determine the subsequent spray development with a considerable impact on the combustion and pollutant formation. Therefore, the processes should be understood as much as possible; for instance, to develop mathematical and numerical models. However, the experimental difficulties are extremely high, especially near the injector nozzle or inside the nozzle, due to the very small geometrical scales, the highly concentrated optical dense spray processes and the high speed and drastic transient nature of the spray. In this study, several unique and partly recently developed techniques are applied for detailed measurements on the flow inside the nozzle and the spray development very near the nozzle. As far as possible, the same three-hole injector for high pressure diesel injection is used to utilize and compare different measurement approaches. In a comprehensive section, the approach is taken to discuss the measurement results in comparison. It is possible to combine the observations within and outside the injector and to discuss the entire spray development processes for high pressure diesel sprays. This allows one to confirm theories and to provide detailed and, in parts, even quantitative data for the validation of numerical models.

Detecting and Correcting Cylinder Imbalance in Direct Injection Engines

2000 ◽  
Vol 123 (3) ◽  
pp. 413-424 ◽  
Author(s):  
M. J. van Nieuwstadt ◽  
I. V. Kolmanovsky
Keyword(s):  
High Pressure ◽  
Diesel Engine ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Direct Injection Engines ◽  
High Speed Diesel ◽  
On Line ◽  
Manufacturing Accuracy ◽  
Adaptation Scheme

Modern direct injection engines feature high pressure fuel injection systems that are required to control the fuel quantity very accurately. Due to limited manufacturing accuracy these systems can benefit from an on-line adaptation scheme that compensates for injector variability. Since cylinder imbalance affects many measurable signals, different sensors and algorithms can be used to equalize torque production by the cylinders. This paper compares several adaptation schemes that use different sensors. The algorithms are evaluated on a cylinder-by-cylinder simulation model of a direct injection high speed diesel engine. A proof of stability and experimental results are reported as well.

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.

Particle Transport Analysis of Sand Ingestion in Gas Turbine Engines

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Klaus Brun ◽  
Marybeth Nored ◽  
Rainer Kurz
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Transient Flow ◽  
Near Field ◽  
Software Tool ◽  
Impact Behavior ◽  
Jet Engines ◽  
Particle Injection ◽  
Statistical Probability ◽  
Output Information

Significant interest exists in the military and commercial aerospace industry to better predict and improve the durability of gas turbine jet engines that are operating in hostile desert environments, specifically, jet engines that see significant inlet sand or ash ingestion. This paper describes the development of a mixed CFD-empirical software tool that allows a detailed analysis of the kinematic and impact behavior of sand and other particulates in the near-field of turbomachinery blades and impellers. The tool employs a commercially available CFD solver to calculate the machine’s transient flow field and then uses the output to determine a set of nondimensional coefficients in a set of empirical functions to predict the statistical probability of particles impacting on rotating or stationary surfaces. Based on this tool’s output information, improved inlet air filtering techniques, optimized engine maintenance practices, and component designs can be realized. To determine the empirical coefficient and to validate the method, PIV testing was performed on an airfoil in a wind tunnel; then particle injection into a simple rotating impeller was tested on SwRI’s high-speed compressor test rig. Results from these tests allowed optimizing of the model to reflect rotating machinery particle impact behavior more accurately.

Numerical Simulation of a High Pressure Supersonic Multiphase Jet Flow Through a Gaseous Medium

2004 ◽  
Author(s):  
Randy S. Lagumbay ◽  
Oleg V. Vasilyev ◽  
Andreas Haselbacher ◽  
Jin Wang
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Gaseous Medium ◽  
Fuel Injection ◽  
Stokes Equations ◽  
Complex Structure ◽  
Jet Flow ◽  
Multiphase Model ◽  
Mixture Density ◽  
Flow Through

Computational Fluid Dynamics (CFD) analysis is used to numerically study the structure and dynamics of a high-pressure, high-speed jet of a gas/liquid mixture through a gaseous medium close to the nozzle region. The complex structure of the jet near the nozzle region is captured before it breaks-up downstream. A new multiphase model based on a mixture formulation of the conservation laws for a multiphase flows is used in the simulation. The model does not require ad-hoc closure for the variation of mixture density with pressure and yields thermodynamically accurate acoustic propagation for multiphase mixtures. The numerical formulation has been implemented to a multi-physics unstructured code “RocfluMP” that solves the modified three-dimensional time-dependent Euler/Navier-Stokes equations for a multiphase framework in integral form. The Roe’s approximate Riemann solver is used to allow capturing of shock waves and contact discontinuities. For a very steep gradient, an HLLC scheme is used to resolved the isolated shock and contact waves. The developed flow solver provides a general coupled incompressible-compressible multiphase framework that can be applied to a variety of supersonic jet flow problems including fuel injection systems, thermal and plasma spray coating, and liquid-jet machining. Preliminary results for shock tube analysis and gas/liquid free surface jet flow through a gaseous medium are presented and discussed.

Application of HFRT Methods to Diagnose the Technical Condition of High-Speed Marine Diesel Engines

2015 ◽  
Vol 236 ◽  
pp. 161-168
Author(s):  
Tomasz Lus
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Technical Condition ◽  
Injection System ◽  
Engine Fuel ◽  
Naval Academy ◽  
Marine Diesel

The paper presents problems related to testing of the technical condition of high-speed marine diesel engines that are not equipped with indicated valves, as it is in the case of larger medium-and low-speed marine internal combustion engines. In this case, in assessment of technical condition of engine fuel injection system and valve gear system a vibration signals (in time / angle domain) analysis modified method called HFRT (High Frequency Resonance Technique) can be used. This method indirectly helps also to evaluate the fuel combustion process in the engine cylinders. The paper presents the theoretical basis of a modified HFRT method, physical implementation of the marine diesel engine system’s analyzer used for marine engines testing built at the Institute of Construction and Operation of Ships at Polish Naval Academy (PNA) in Gdynia. The paper also includes a description of the vibration signal processing methodology and examples of measurements made in the ships conditions for a few selected types of engines.

scholarly journals Quantitative predictions of cavitation presence and erosion-prone locations in a high-pressure cavitation test rig

2017 ◽  
Vol 819 ◽  
pp. 21-57 ◽  
Author(s):  
Phoevos Koukouvinis ◽  
Nicholas Mitroglou ◽  
Manolis Gavaises ◽  
Massimo Lorenzi ◽  
Maurizio Santini
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Transient Flow ◽  
Mass Transfer Rate ◽  
Operation Time ◽  
Working Fluid ◽  
Experimental Investigations ◽  
Micro Ct ◽  
Mixture Phase ◽  
Cavity Shedding

Experiments and numerical simulations of cavitating flow inside a single-orifice nozzle are presented. The orifice is part of a closed flow circuit, with diesel fuel as the working fluid, designed to replicate the main flow pattern observed in high-pressure diesel injector nozzles. The focus of the present investigation is on cavitation structures appearing inside the orifice, their interaction with turbulence and the induced material erosion. Experimental investigations include high-speed shadowgraphy visualization, X-ray micro-computed tomography (micro-CT) of time-averaged volumetric cavitation distribution inside the orifice as well as pressure and flow rate measurements. The highly transient flow features that are taking place, such as cavity shedding, collapse and vortex cavitation (also known as ‘string cavitation’), have become evident from high-speed images. Additionally, micro-CT enabled the reconstruction of the orifice surface, which provided locations of cavitation erosion sites developed after sufficient operation time. The measurements are used to validate the presented numerical model, which is based on the numerical solution of the Navier–Stokes equation, taking into account compressibility of both the liquid and liquid–vapour mixture. Phase change is accounted for with a newly developed mass transfer rate model, capable of accurately predicting the collapse of vaporous structures. Turbulence is modelled using detached eddy simulation and unsteady features such as cavitating vortices and cavity shedding are observed and discussed. The numerical results show agreement within validation uncertainty with the obtained measurements.

Development of a High-Pressure, High-Temperature, Optically Accessible Continuous-Flow Vessel for Fuel-Injection Experiments

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Kemar C. James ◽  
Jin Wang ◽  
Michael C. Maynard ◽  
Zackery B. Morris ◽  
Brian T. Fisher
Keyword(s):  
High Pressure ◽  
Continuous Flow ◽  
High Speed ◽  
Fuel Injection ◽  
Light Emitting Diode ◽  
Cone Angle ◽  
High Speed Camera ◽  
Light Emitting ◽  
High Pressure High Temperature ◽  
Spray Visualization

A vessel has been designed for nonreacting fuel-injection experiments with continuous flow of sweep gas at pressures up to 1380 kPa and temperatures up to 200 °C. Four orthogonal windows provide optical access for high-speed spray-visualization using a fast-pulsed light emitting diode (LED) and a high-speed camera. Initial experiments have been conducted to determine spray characteristics of n-heptane. At room conditions, liquid length and cone angle were 170 mm and 14.5 deg, respectively. With air flow in the chamber at 690 kPa and 100 °C, liquid length was considerably shorter at 92 mm and cone angle was wider at 16.5 deg.

Analysis of the effect of variations in fuel line pressure in high-speed direct injection diesel engines, with high-pressure common rail fuel injection systems on heat release, cylinder pressure, performance, and NOx emissions

2005 ◽  
Vol 219 (3) ◽  
pp. 413-422 ◽  
Author(s):  
F J Wallace ◽  
J G Hawley
Keyword(s):  
High Pressure ◽  
Heat Release ◽  
Diesel Engines ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Common Rail ◽  
Injection Velocity ◽  
Engine Simulation ◽  
High Pressure Common Rail

This paper is a further development of work previously reported on a wholly analytical approach to heat release modelling and is applicable to high-speed direct injection (HSDI) diesel engines operating with high-pressure common rail fuel injection systems under conditions of predominantly mixing-controlled combustion. The key variable in this treatment is the fuel preparation or combustion rate factor WH which, in conjunction with the primary injection variables, i.e. rail pressure, injection velocity and duration, defines the shape and amplitude of the heat release curve. It was shown in a previous paper that by expressing the fuel preparation rate factor WH as a function of time rather than crank angle, i.e. WHt instead of WHθ, the former can be presented as a nearly linear function of the square of injection velocity, i.e. WHt is directly proportional to the kinetic energy of the injected fuel spray, the latter evidently being the primary influence on the rate of the fuel-air mixing process. The analytical treatment developed in the authors' previous paper then allows heat release rates in the engine, dQ/dθ, to be calculated over a wide range of engine speeds and loads, with the aid of the existing engine simulation code ODES (Otto diesel engine simulation) to predict the associated engine performance and emissions, without resorting to further engine testing.

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