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Advanced Technology Consultants

Laguna Niguel, California
USA    92677
Tel: 949 467 9233
(001 prefix outside USA)

Lugano, Ticino
Switzerland 6900



Liquid Atomization, Sprays, and Fuel Injection Technologies    
Oscillating poppet injector producing a hollow-cone spray [left image)
Interacting-sprays injection system shown at different crankangles (or time). Note that sprays impinging the far cylinder wall
(picture is taken by sending a pulsed laser sheet and imaging from cylinder head using ICCD digital camera) [right image)


Atomization of liquids is at the very heart of operations of many of the devises we use on a daily basis. From our shower in the morning (liquid water atomization process at the shower head), to liquid-fueled engines in ground transportation, to gas turbine in airplanes/power stations and rocket engines , we rely on the efficient and low-pollutant-level operation of these devices. This seminar is based on the realization and proven experience that knowledge of technological practices and advances in one discipline, say, diesel fuel injection, is highly beneficial to engineers in other areas of  engineering and technology such as, for examples, gasoline direct injection (GDI) or rocket engines and vice versa.  


This  seminar is about understanding the processes of liquid atomization and spray formation and relating this understanding to fuel injection systems and emission of pollutants  in modern engines. Fuel injection is the key to smooth, efficient, and low-emission operation of the gasoline-fueled engines. In diesel and GDI  engines, it is shown that the story is also the same and even more critical. In the aerospace industry, the engine thrust, efficiency, and the emission levels are directly related to the performance of the liquid fuel injector designs. In short, the liquid fuel atomization and spray formation is in the heart of the majority of stationary and mobile power generation machines. Other areas such as electrostatic car-body spray painting, agricultural crop spraying, ink jet printing, pharmaceutical nebulizers, spray drying, and chemical liquid rockets, are just a few examples of the very wide applications of the liquid spray production


The approach in this course is to build sufficient background through  introduction of a consistent and widely-used terminology in sprays and atomization. Justifications, reasons, and purposes of the liquid atomization and spray formation are discussed along with presentation of different designs of atomizers and nozzles employed in various industries.  Characterization methods of sprays are discussed after the definition and meaning of different averaged liquid droplet diameters are touched. Droplet size measurement devices are covered and examples are shown. Armed with these critical background information, the focus of the course is then  heavily directed to the gasoline and diesel fuel injections, injector designs and their performance requirements for optimum engine operation with lowest possible emission of  harmful pollutants.


Benefits of Attending:

∑ Upon completion of this seminar, you will:
∑ Understand and be familiarized with important terminology commonly used in atomization and sprays
∑ Gain a general physical understanding of the important processes in atomization and spray formation
∑ Possess adequate background and foundation to educate yourself beyond the depth and topics covered
∑ Be able to intelligently  judge, adapt, and, transfer technological advances from one discipline to  the other
∑ Understand effects of injection system design and operating conditions on engine performance, combustion and emission of pollutants
∑ Be able to communicate intelligently with engineers working on injector and injection system design aspects in your company
∑ Grasp the technology and the logic behind different injector designs

∑ Gain sufficient knowledge to intelligently contribute to human being's efforts in minimizing emission of pollutants and maximizing 
             efficient usage of earth's energy resources
∑ Anticipate future trends and technology developments in fuel injection
∑ Learn and appreciate the role the injection system plays in combustion and emission and how it is used to provide guidance in design 

            of low-emission combustion systems
∑ Effectively contribute to the design of the critical components such as intake valve and induction system


Who Should Attend:

This seminar will be especially valuable for engineers, technical and project managers, researchers, and academicians in the automotive and aerospace industries. In the automotive industry, engineers working on the design of components for high efficiency and performance of combustion engines, particularly  those directly and indirectly involved in reducing emission of harmful pollutants from combustion engines, will highly benefit from this course. Additionally, this course provides adequate background for engineers and managers in contact with those directly involved in the fuel injection systems. Therefore, this course experience prepares the attendees for a more efficient and intelligent communication in an interdisciplinary technological environment. Furthermore, aerospace engineers involved in the design of the gas turbine o
r rocket engines' combustion chambers will find the course useful and enlightening.  The course is also of interest to academicians wishing exposure to the field and those engineers active in development and applications of software, modeling in-cylinder injection combustion and emission processes.


How to Arrange for a Presentation:

Due to ATC's low overhead, direct-contact clients are offered a  competitive and cost-effective package.  Individuals interested in these seminars should contact Advanced Technology Consultants (ATC) directly. Alternatively,  this seminar (prepared by the ATC and delivered by a award-winning ATC consultant) are also sponsored by the Society of Automotive Engineers (


Electronic and hard copies of the seminar materials can be purchased and are only available through ATC. Contact ATC for price and shipping.

NOTE: Professionally-prepared "audio-video Powerpoint-type presentations" of these seminars are available for purchase by the companies. Each slide is presented with a clear audio by the consultant, describing the subject, while a digital pointer guides the audience to where the attention is to be focused. Companies can put such audio-video presentations on their intranet to be used by their employees. It is a cost effective way of approaching  professional training which also contributes towards R&D, design, and intelligent new product development. Presentations are updated every year at a fraction of the original cost.  For a sample presentation click on the word "SPRAYS" in the picture to get a feel of how information is transferred (High-speed internet access is recommended. Otherwise, download may take a few more minutes). For more details and pricing please contact ATC.




Seminar Content

Day 1

∑ Description of the Atomization Process 
∑ Disintegration of the liquid jets
    ∑ Rayleigh criterion (no viscosity)
    ∑ Weber's criterion (effects of viscosity)
    ∑ Ohnesorge criterion for atomization (Ohnesorge Number)

    ∑ Liquid Breakup regimes 
        ∑ Rayleigh regime
        ∑ First wind-induced breakup regime
        ∑ Second wind-induced breakup regime
        ∑ Atomization regime
    ∑ Influence of some parameters
        ∑ Jet velocity profile

        ∑ Nozzle length-to-diameter ratio
        ∑ Ambient pressure
    ∑ Disintegration of liquid sheets
    ∑ Drop breakup in air flow, turbulent flow, and viscous flow
∑ Types of Atomizers
    ∑ Pressure atomizers 

    ∑ Air-assist atomizers 
    ∑ Air-blast atomizers 
    ∑ Effervescent atomizers
    ∑ Electrostatic atomizers 
    ∑ Ultrasonic atomizers
    ∑ Diesel injector
    ∑ Gasoline-fueled injectors
∑ Drop size distribution and measurements
    ∑ Graphical and mathematical representation of drop size distribution 
    ∑ Averaged diameter and representative diameters
    ∑ Measurement techniques 
        ∑ Patternation
        ∑ Drop size measurements and spray characterization
            ∑ Mechanical methods
            ∑ Drop collection on slides
            ∑ Molten-wax and frozen-drop approach
            ∑ Cascade impactors
            ∑ Electrical
                ∑ Charged-wire and hot-wire methods
            ∑ Optical methods
            ∑ Imaging-- photography and holography
            ∑ Single-particle light scattering (Phase Doppler Particle 

                Analyzer, etc.)
          ∑ Diffraction size analyzer
    ∑ Drop evaporation

Day 2

∑ Gasoline port fuel injectors and injection system
    ∑ Multipoint port injection system
        ∑ Classes of gasoline port injectors
            ∑ Low pressure injectors
            ∑ Medium pressure injectors 
            ∑ High pressure injectors

            ∑ Air-assisted injectors
            ∑ Swirl injectors
            ∑ Heated vaporizing injectors

            ∑ Ultrasonic injectors
            ∑ Electrostatic injectors
        ∑ Key requirements of gasoline port injectors
        ∑ Deposit considerations
    ∑ Single-point throttle body injection system
    ∑ Feedback system
    ∑ Effects of injection parameters on engine performance and emission
        ∑ Injection timing and scheduling 
        ∑ Spray targeting
        ∑ Spray momentum
        ∑ Mean drop size and size distribution
        ∑ Pulse-to-pulse variability
        ∑ Others
∑ Flow of fuel and air in intake manifolds
∑ Details of Gasoline direct injection (GDI) and its effects on engine performance and emission of pollutants

    ∑ Comparison with Port Fuel Injection
    ∑ General operating strategy
    ∑ Injector requirements and spray characteristics
    ∑ Applications of different injector designs
    ∑ Fuel-air mixing processes
    ∑ Combustion control strategies
    ∑ Combustion chamber designs
    ∑ Injector deposits
    ∑ Unburned hydrocarbon and NOx emissions
    ∑ Future prospects

∑ Spray modeling and demonstration of computer software for spray calculation in engines

Day 3

∑ Diesel fuel spray, injector and injection system 
    ∑ Fuel injection system
        ∑ Pumps
            ∑ In-line injection pump
            ∑ Distributor-type injection pump

            ∑ Single-barrel injection pumps
            ∑ Unit injector & unit pump

        ∑ Injector designs
            ∑ Nozzle holder
            ∑ Nozzles
            ∑ Others
    ∑ Overall spray structure
    ∑ Liquid fuel atomization

    ∑ Spray angle
    ∑ Intact core length
    ∑ Spray penetration
    ∑ Effects of several parameters on mean droplet diameter
    ∑ Spray evaporation
    ∑ Ignition delay
    ∑ Effects of fuel injection parameters on ignition delay period
    ∑ Mixing-controlled combustion
    ∑ Effects of fuel injection parameters on ignition delay  and on engine performance, efficiency, and emissions
    ∑ HC emission mechanisms in diesel engines and its relation to fuel injection
    ∑ A brief on soot formation and fuel sprays
    ∑ Advanced topics (details of split injection, common-rail injection, interacting-sprays
   injection, ultra-high pressure fuel injection, and others effects on performance and emissions)
∑ Summary and conclusion



"Excellent introduction to atomization and fuel injection flow dynamics."
Richard Moon
UAV Engine Program Manager
Advanced Ceramics Research



Instructor:  Bruce Chehroudi  

Dr. Chehroudi, has accumulated years of technical and leadership experiences in different capacities and organizations. This includes such positions as a Principal Scientist and Group Leader appointment at the Air Force Research Laboratory (AFRL) ERCInc, a Chief Scientist at Raytheon STX, a Visiting Technologist at Fordís Advanced Manufacturing Technology Development (AMTD) center, a tenured Professor of Mechanical Engineering at Kettering University and University of Illinois, and served as a Senior Research Staff/Research Fellowship at Princeton University. Dr. Chehroudi directed numerous multimillion dollar interdisciplinary projects in areas involving chemically reacting flows, combustion and emission of pollutants, sustainable and alternative energy sources, distributed ignition, material/fuel injection, advanced pollution reduction technologies, propulsion concepts, gas turbine and liquid rocket engines, combustion instability, laser optical diagnostics, spectroscopy, supercritical fluids and applications in environmental and propulsion systems, advanced composites, MEMS, nanotechnology, and micro fluidics. He has won many merit and leadership awards by such prestigious organizations as the Society of Automotive Engineers (1. Arch. T. Colwell Merit Award for technical excellence only to top 1% yearly, 2. Ralph R. Teetor Award for outstanding teaching/research/leadership, 3. Forest R. McFarland Award for sustained leadership in professional and educational service and a key contributor to the Continuing Professional Development Group, 4. Appreciation Award for 10 years of dedicated and inspiring  service and commitment to providing quality technical education, and  5. Outstanding Faculty Advisor), American Institute of Aeronautics and Astronautics (Best Publication Award of the Year), Air Force Research Laboratories (1. Outstanding Technical Publication Award, and 2. STAR Team Award for demonstrating world-class combined scientific and leadership achievements), Institute of Liquid Atomization and Sprays Systems (Marshall Award for best publication with lasting contributions), Liquid Propulsion Sub-committee of Joint Army-Navy-NASA-Air Force (JANNAF) (Best Liquid Propulsion Paper Award involving undergraduate/graduate students),  and the 2nd International Symposium on Turbulence and Shear Flow Phenomena (Top 10 Technical Publication Award). He has been a consultant with many organizations such as, Ford, GM, Honda R&D, AFRL, Honeywell, NASA, AFOSR, VW, Bosch, Siemens, NGK, Cummins, and TRW. Through professional societies, Dr. Chehroudi delivers invited professional seminars on Management of R&D Teams and Organizations, Management of Innovation, Combustion and Emission of Pollutants in Automotive and Gas Turbine Engines, Ignition Issues, Gasoline Direct Injection engines, R&D on Homogeneously-Charged Compression Ignition (HCCI) engines, and Liquid Injection Technologies. He has a PhD in Mechanical & Aerospace Engineering and Post-Doctoral Fellow (Princeton University), MS in Mechanical Engineering (Southern Methodist University, Summa Cum Laude), MS in Economics (Swiss Finance Institute, Magna Cum Laude), a senior member of American Institute of Aeronautics and Astronautics Propellant & Combustion Committee (2008-present), and is an Associate Fellow of American Institute of Aeronautics and Astronautics. Dr. Chehroudi acts as a reviewer for many scientific and engineering journals and publishers, has delivered over 200 presentations in technical meetings and to nontechnical audiences, over 20 technical reports (Princeton University, General Motors, Ford Motor Co, Department of Energy, NASA, Air Force Research Laboratory), five 600-plus-page monographs on combustion and emission of pollutants from mobile power plants, ignition technologies, liquid material injection, and nanotechnology,   two book chapters on propulsion system combustion instability and applications of graphene (a nanotech product) in ignition and combustion of fuels, ground-breaking patents on applications and synergy between nanotechnology, light, and chemical reaction for a light-activated distributed ignition of fuel-air mixtures, and has more than 150 publications with extensive experience in both scientific and management areas and intensive trainings in finance and financial engineering


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