ILASS - AmericasInstitute for Liquid Atomization and Spray Systems - North and South America. Editor: Prof. Chris F. Edwards |
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TECHNICAL COMMITTEE REPORTS Propulsion (Gas Turbine and Rockets) As announced at the 1995 ILASS meeting, the name of the committee was changed to include the additional activity represented by the Rocket Propulsion members of the technical committee. A total of 17 members were in attendance at this meeting as compared to 20 in the 1995 meeting at Troy, Michigan. This accounts for a total of 26 interested members in the ILASS Gas Turbine & Rocket Propulsion Technical Committee. A notable attendee was Vladimir Bazarov, Moscow State Aviation Institute, who expressed an interest in all the fuel injector technologies! Eleven attendees 53% (1995, 55%) represented Industry, five attendees, 29% (1995, 30%) represented Academia, while three attendees. 18% (1995, 15%) represented Government Agencies. Based on the responses to the questionnaire filled by each attendee, the following profile of interest was identified as charter technical subjects for the Gas Turbine & Rocket Propulsion Technical Committee of ILASS: I. Primary Application - Gas Turbine/Multi Fuels. 27% (1995, 25%) Interest - Gas Turbine-Low Emissions 30% (36%) - Rockets 33% (25%) - Other 10% (14%) II. Fuel Injector - Pressure Atomization 18% (16%) Concept Interest - Air Assist Pressure 13.3% (12%) - Air Blast 13.3% (13%) - Air Shear 10.8% (13%) - Effervescent 13.3% (13%) - Co-Jet 14.3% (16%) - Interacting jets 12% (13%) - Other 5% (4%) III. Information - Experimental Data 35% (46%) Desired - Empirical Correlations 32.5% (32.5%) - Theoretical Predictions 32.5% (32%) IV. Members willing to submit a technical abstract for the 1997 ILASS Meeting 71% (75%) ACTION ITEMS: Curt Scheuerman - Midwest/East Doug Talley - West/Northwest Ted Koblish - Southeast/Southwest Industrial Sprays The Industrial technical committee members represented users of sprays (Coatings, Chemical Manufactures, consumer products, Nozzle manufacturers, and University researchers. Environmental regulatory efforts continue to be drivers of change in industrial applications A better understanding of fundamental liquid fluid property effect on spray performance is needed. Non-Newtonian liquid characteristics are of the most industrial interest. The discussion included methods to transition from technology to science as well as increasing the level of science in this area. It was thought that review papers might be a step along this path first dealing with Newtonian liquid viscosity. Environmental regulation changes are forcing product reformation that changes spray performance. 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. Very fruitful and enlighten discussion can focus on common area of base technology (everybody needs to practice well) and thus avoiding the competitive technology. Boiler/Furnace/Incinerator Sprays A meeting of the Boiler/Furnace technical committee was held during ILASS-96 in San Francisco. Present at the meeting were: John Hurley, Combustion Components The majority of our discussion centered around how to augment involvement of the boiler and furnace community in ILASS. Steve Londerville suggested tapping into the American Flame Research Committee, the ASME fuels group, and others. It was generally agreed that ILASS information is sent to too narrow an audience and that the ILASS-Americas mailing list should be expanded. John Hurley offered that the location was important and that seeing one or two key papers in the program can make the difference. In his case, it was the Coen paper that had peaked his interest to attend. Use of a key speaker in the area of boilers/furnace as a drawing card was discussed, as was the idea of soliciting papers for a special session. John also supplied a list of key industrial contacts with interests in sprays. A list of applications, issues and interests was also drawn up and discussed, as listed below.
The meeting convened at 5:45PM with 12 participants; the co-chair, Dr. Nader Rizk could not attend due to unforeseen circumstances. Following an Agenda previously distributed to members of the Committee, the discussions started regarding the state of the art predictions for drop size distributions from injectors. It was pointed out that predictive models do not exist for a variety of injectors both for primary and secondary atomization. This is due to the lack of definitive measurements showing the phenomena occurring during atomization. If such information were available, it was pointed out that DNS calculations of sheet breakup could be carried out. Other techniques could also be used, such as LES and surface tracking. The questions of geometry and the coupling with the outer flow field (i.e. that not immediately adjacent to the atomizing jet) were seen as crucial. Industrial participants pointed out that there is an increasing emphasis in industry to use CFD codes to predict accurate quantities; currently, however, all that can be expected from CFD atomization codes is qualitative predictions as a function of parameter variation. The issue of interaction of drops with turbulence and the prediction of unsteadiness during combustion were also discussed in the context of the industrial need to control processes in gas turbine engines. The need to predict the drop interaction with different turbulent scales was viewed as crucial when combustion is present because chemistry occurs at very small scales. The Eulerian-Lagrangian technique involving solving the flow equations in an Eulerian frame and following the drops on their trajectories was seen appropriate only for laminar, dilute situations. This is because if such a technique is used to represent groups of drops with a single representative drop, the volume of the group must remain much smaller than the Eulerian computational cell. If this requirement is not satisfied, the model biases the calculation of the flow (due to coupling between representative drops and flow) by putting too much mass, momentum and energy on each trajectory of representative drops. The meeting ended at 7:15PM without covering all points of the Agenda. Measurements/Instrumentation
Review List of "Living Issues" - the committee reviewed the list of "living issues" and suggested the following additions: Review List of "Living Measurement Methods" - the committee reviewed the list of "living measurement methods" and suggested the following additions: Report of the Ad Hoc Committees:
(ii) Spray Characterization (Chien-Pei Mao, Delavan) |