Newsletter #20


ILASS - Americas

Institute for Liquid Atomization and Spray Systems - North and South America.

Editor: Prof. Chris F. Edwards
Secretary, ILASS-Americas
Mechanical Engineering Dept.
Stanford University
Stanford, CA 94305-3032

Newsletter # 20 - January, 1996


The ILASS-96 Annual Meeting will be held on Fisherman's Wharf in San Francisco:

The meeting is hosted by the Coen Burner Company of Burlingame, California. Steve Londerville and Scott Drennan of Coen have arranged a magnificent setting and an impressive arena for this Ninth Anniversary Meeting of ILASS-Americas.

We are indebted to Dave Harrington of General Motors for the remarkable success of the 1995 Annual Meeting in Troy Michigan. The meeting hit all-time attendance records, enjoyed the largest selection of papers ever presented, and included an informative and impressive visit to the GM Research and Development Center. Josette Bellan served as the Program Chair and created a solid menu of papers that reflected the latest in spray science and technology with excellent (and thought provoking) invited presentations from the automotive industry (paints and coatings, and fuel/air mixture preparation), and the haircare industry.

We are excited about the strength, vitality, and spirit of ILASS-Americas as we reach the milestone of our first decade in the life of this special organization. It is an organization that brings together, for four days, people from diverse backgrounds-a vast array of technologies, university faculty and students, industry managers and researchers, technologists, scientists-all of whom share in common the utilization of liquid sprays and the fascinating and varied challenges associated with the transformation of a liquid to droplets.

No one better represents the spirit of ILASS-Americas than Dwight Senser whose life was suddenly and unexpectedly taken while on business just a few months ago. Dwight's pleasant and enthusiastic demeanor, and courage to bridge academia to tough practical applications in sprays, serves as a model and memory of the very best of ILASS-Americas. We are indebted to his life, and the opportunity to have known him, worked with him, and been touched by his enticing "spirit."

We look forward to seeing you in California in May.

                                               Scott Samuelsen
                                              Chair, ILASS-Americas


We are saddened to announce the loss of our colleague and friend, Professor Dwight Senser of the University of Wyoming earlier this year. Dwight has long been an active and enthusiastic participant in ILASS, and in the field of sprays, and will be greatly missed. He is survived by his wife Shari and four children (ages 3 to 7 years). A fund has been set up to assist with educational expenses for the children. Checks may be made payable to the Senser Children Memorial Fund and sent to: UniWyo Federal Credit Union, Senser Children Memorial Fund, 564 N. 15th Street, Laramie, WY 82071


The Eighth Annual ILASS-Americas Conference was held May 21 - 24, 1994 at the Somerset Inn, Troy, Michigan. The meeting was the largest yet with 171 attendees. Three invited papers, fifty-four presentation papers, and ten poster papers were given on subjects that included: Coatings and Materials, Atomization and Spray Modeling, Performance of Spray Systems, Agricultural Sprays, Instrumentation and Measurement Techniques, Atomization Measurements, and Reciprocating Engine Sprays. Thanks are due to Dave Harrington (Local Arrangements Chair), Josette Bellan (Papers Chair), and the students from Wayne State who helped with registration. Copies of the Book of Abstracts are available at a cost of $75 each from the ILASS Secretariat at the Mechanical Engineering Department, U.C. Irvine, Irvine, CA 92717-3550. Please make checks payable to ILASS-Americas.


The Annual Business Meeting of ILASS-Americas was held during the conference banquet on May 23, 1995 at the Somerset Inn, Troy, Michigan. Chair Samuelsen opened the meeting by reporting on the health and status of ILASS-Americas. He noted that we now have over 500 members and are one of the three regional ILASS organizations responsible for the triennial ICLASS Conference. Chair Samuelsen then introduced Prof. Hiroyasu, chair of the International Council of ICLASS, the At-Large Board Members, Past-Chair, and Officers of ILASS, and gave some background on the history of the Institute.

The minutes of the previous ABM (June '94) were read by the Secretary and approved following a motion by Scott Drennan. Chair Samuelsen recognized those who had contributed to the success of the conference. These included Dave Harrington, the Local Arrangements Chair, Josette Bellan, the Papers Chair, Don Moran, the Display Coordinator, and M-C. Lai and his students from Wayne State who helped with registration. Meeting sites were then announced for the next two years. The 1996 meeting will be held at Fisherman's Wharf in San Francisco, hosted by Scott Drennan and Steve Londerville of the Coen Company. The 1997 meeting will be held in Ottawa, hosted by Greg Smallwood and the NRC Canada.

Treasurer Reitz reported that the ILASS treasury currently holds assets of $33,920. He noted that it was lower than the previous year due to payment of travel support to students attending ICLASS. The Treasurer's Report was approved following a motion by Rex Harvey.

The student presenters and invited speakers were recognized and thanked for their contributions to the conference. It was announced that a new student presentation award would be given in subsequent years. Presentation of the Marshall Award for the best technical contribution to ILASS-94 was made to Rolf Reitz and M. A. Patterson of the University of Wisconsin, Madison.

The Annual Business Meeting was adjourned following a motion by Curt Scheuerman

Signed _______________________ Chris F. Edwards, Secretary


The Seventh International Conference on Liquid Atomization and Spray Systems (ICLASS-97) will be held in Seoul, the capital city of Korea, on the week of August 18 to 23, 1997. Scientists, engineers, and others interested in atomization and sprays are invited to attend and participate in this event.

Prof. C. W. Lee is chair of the paper selection committee. Abstracts should be submitted by June 1, 1996, completed manuscripts by December 1, 1996, and camera-ready copy by May 1, 1997. Please see the conference announcement enclosed with this newsletter.

Atomization and Sprays JOURNAL

Registrants at ILASS-95 in Troy will receive Volume 5 (1995), issues 1-6 from the publisher. Some registrants will also receive issues 1-3 of Volume 6 (1996). Subscribers who do not intend to participate in ILASS-96 in San Francisco should send their annual personal subscription ($60) to the publisher, Begell House, at 79 Madison Avenue, New York, NY 10016-7892. Personal subscriptions are for personal use only--the journal should not be distributed to colleagues. Instead, each member of ILASS is urged to persuade their library to take out an institutional subscription ($200). The current total number of subscribers (U.S., Europe, Asia, institutional and personal) is 450.

(Reports from the Technical Committee meetings and Tutorials held at the Troy Conference. Additional reports will appear in the next issue of the Newsletter.)

Boiler/Furnace/Incinerator Technical Committee
Chair:	Chris Edwards, Sandia National Laboratory
Co-Chair:	Steve Londerville, Coen Company

The inaugural meeting of the Boiler/Furnace/Incinerator Technical Committee of ILASS-Americas was held at ILASS-95 in Troy, Michigan. Eight members were present, with representation from industry, universities, and research laboratories. After brief introductions in which each member discussed their background and reasons for interest in the committee, the group began development of a list of issues for discussion. The list formulated included:

  • The status of CFD simulations for real spray processes. In particular, how to include Lagrangian droplet characteristics and clustering effects.
  • The need to control droplet size distributions in recovery boilers. In particular the need to maintain a lower limit on the size to avoid ash particulate emission.
  • The need for better measurements in recovery boilers. Enhanced survivability of diagnostics in this environment will be necessary to permit useful measurements of velocity fields, etc.
  • NOx as a driver for conventional boiler design. Other pollutants (such as char) also playing a role through the oxidation/reduction tradeoff.
  • The need to define just what an ideal spray characteristic might be for any given application. It was generally recognized that smaller is not necessarily better and that it is not clear whether such ideal, band-limited sprays can actually be produced.
  • That the extreme liquid properties of real fuels and their variability substantially complicate each of the issues discussed above. The remainder of the meeting was spent discussing these issues and citing examples of the atomization-related constraints applicable to these real-world spray devices.

    Industrial Technical Committee

    Chair: Chuck Lipp, Dow Chemical
    Co-Chair: Paul Sojka, Purdue University

    The Industrial technical committee members represented users of sprays (coatings, chemical manufacturers, consumer products, nozzle manufacturers, and university researchers). Environmental regulatory efforts continue to be drivers of change in industrial applications

    A better understanding of fundamental property effects on spray performance is needed. Properties of interest include:

    1. liquid viscosity
    2. liquid dynamic surface tension
    3. liquid turbulence
    4. non-Newtonian liquid characteristics

    Two approaches were discussed describing the relationships between properties and performance- correlations, such as those found in Lefebvre's book and fundamental relationships, such as those derived from instability theory. The ability to predict drop size distributions, or at least the distribution width, is of interest to the entire industrial spray community. Some are concerned with the presence of fines while others about so-called rogue drops. We concluded there is no method available for predicting drop size distributions, for the impact of properties/operating conditions on that size distribution. Air entrainment in sprayed coatings provides a significant challenge with the next generation low solvent materials.

    Environmental regulation changes are forcing product reformation which changes spray performance. This includes drop size as well as other spray attributes (evaporation rates, entrainment, drop size distribution, spray pattern, drop velocity distribution).

    The Chemical Engineering community (spray drying) is not well represented and additional efforts would be fruitful.

    A discussion of possible collaborative research and development programs indicates that partial funding for this is available through CRISP as well as NIST. Typically these are large programs. CRISP is the NSF program-intellectual property rights therefore reside with the Government/University. The NIST program requires that intellectual property rights reside with the industrial partner(s).

    Diesel and Automotive Technical Committee

    Chair: Rolf Reitz, University of Wisconsin;

    Co-Chair: Dave Harrington, General Motors

    The committee meeting was very well attended. Considerable time was spent in a lively discussion of recent research developments relating to fuel injection and performance in SI and diesel engines.

    For SI engines, much of the discussion centered on the factors that influence cold-starting emissions in port fuel-injected engines (i.e., during the first 90 seconds after startup). The reasons for differences in engine emissions with open and closed valve operation were discussed, together with the need for spray targeting to ensure good fuel/air mixing and evaporation. It was suggested that experiments should be designed with fully evaporated fuels to provide comparisons of fuel preparation and engine performance with port injected cases. Also, the need for additional work on modeling fuel film formation and breakup was discussed.

    Small bore, direct in-cylinder fuel injected engines were also discussed. It was noted that Mitsubishi has recently announced a lean-burn (late injection) engine with a 25% improved fuel economy over standard engines under normal driving conditions. This engine has a high compression ratio (12:1) and features a relatively high pressure swirl injector. The engine also features an optimal combustion chamber geometry that allows control over tumble flow motions to control the mixture strength in the vicinity of the spark, even at overall lean operation. It was concluded that CFD modeling of the in-cylinder flow details could be very helpful to be able to understand the role and evolution of the flow structures in these engines.

    Diesel engines were discussed next, with particular emphasis on the factors which limit the use of fuel injection in small bore engines, such as wall-wetting and the requirements for precise injection of small quantities of fuel. It was noted that the core of the diesel spray can be comparable in length to the piston bowl radius and that this can lead to increased smoke emissions. Factors that lead to increased smoke emissions in large bore diesels were also discussed, including the effects of injector-to-injector variability and nozzle cavitation effects.

    Finally, the attendees were encouraged to help explore methods to promote the activities of ILASS and to increase the number of attendees from the automotive, fuel systems and diesel engine industries at future ILASS meetings.

    Agricultural Technical Committee

    Chair: Andrew Hewitt, Stewart Agricultural

    Co-Chair: Ken Giles, University of California, Davis

    The meeting was attended by representatives from universities and industry in countries including the U.S., Canada, U.K. and Israel. The progress of the inter-laboratory study for laser droplet size analyzers was discussed. Testing is continuing as planned.

    Agricultural spray classification techniques were discussed, including cooperation with European (British Crop Protection Council) and U.S. (Association Society of Agricultural Engineers and U.S. Spray Drift Task Force) developments of such schemes.

    The committee Chairman, Andrew Hewitt, announced that the committee membership is steadily growing, and a large agricultural spraying community presence is anticipated at the 1996 ILASS-Americas conference, with several key papers on pesticide application topics. This will be the next time that the committee meets.

    May 6-10 Short Course on Spray Technology, Carnegie Mellon University, Pittsburgh, PA
    May 19-22 ILASS-96, Fisherman's Wharf, San Francisco, CA
    July 7-11 Second International Symposium on Numerical Methods for Multiphase Flows, ASME, San Diego, CA
    July 8- 11 Eighth International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, Portugal
    July 28-Aug. 2 26th International Symposium on Combustion, Naples, Italy

    May 18-21 ILASS-97, National Research Council, Ottawa, Canada
    Aug. 18-22 ICLASS-97, Seoul, Korea

    (Advertisements relevant to sprays and spray technology are accepted for inclusion in the Newsletter after approval on a case-by-case basis. Please contact the Secretary for further information.) One Week Short Course on Spray Technology
    Carnegie Mellon University, Pittsburgh, PA, USA
    May 6-10, 1996

    Lecturers: Dr. William Bachalo, President, Aerometrics
    Professor Norman Chigier, Carnegie Mellon University, and
    Professor Rolf Reitz, University of Wisconsin

    for further information, contact:
    Dr. Norman Chigier
    Department of Mechanical Engineering
    Carnegie Mellon University
    5000 Forbes Avenue
    Pittsburgh, PA 15213-3890
    FAX: 412-268-3348

    One Week Short Course on Gas Turbine Combustion Technology
    Irvine, California
    March 11-16, 1996


    Lecturers: Professor Arthur Lefebvre, Emeritus, Purdue University
    Mr. Donald Bahr, Manager Combustion Tech. (retired), General Electric
    Professor Scott Samuelsen, University of California, Irvine

    for further information, contact:
    Professor Scott Samuelsen
    UCI Combustion Laboratory
    University of California
    Irvine, California 92717-3550
    714-824-7423 (fax)