Active control of lifted diffusion flames with arrayed micro actuators
- 172 Downloads
Active control of a lifted flame issued from a coaxial nozzle is investigated. Arrayed micro flap actuators are employed to introduce disturbances locally into the initial shear layer. Shedding of large-scale vortex rings is modified with the flap motion, and the flame characteristics such as liftoff height, blowoff limit, and emission trend, are successfully manipulated. Spatio-temporal evolution of large-scale vortical structures and fuel concentration is examined with the aid of PIV and PLIF in order to elucidate the control mechanisms. It is found that, depending on the driving signal of the flaps, the near-field vortical structures are significantly modified and two types of lifted flames having different stabilization mechanisms are realized.
KeywordsParticle Image Velocimetry Nozzle Exit Flame Front Vortical Structure Mixture Fraction
This work was supported through the research project on Micro Gas Turbine/Fuel Cell Hybrid-Type Distributed Energy System by the Department of Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Corporation (JST).
- ANSI/ASME PTC 19.1 (1985) Measurement uncertainty. Supplement on instruments and apparatus, part 1, ASMEGoogle Scholar
- Ashurst WT, Williams FA (1990) Vortex modification of diffusion flamelets. The 23rd International Symposium on Combustion, pp543–550Google Scholar
- Chao YC, Jeng MS (1992) Behavior of the lifted jet flame under acoustic excitation. In: Proceedings of the 24th International Symposium on Combustion, pp 333–340Google Scholar
- Everest DA, Feikema DA, Driscoll JF (1996) Images of the strained flammable layer used to study the liftoff turbulent jet flames. The 26th International Symposium on Combustion, pp 129–136Google Scholar
- Fujimori T, Riechelmann D, Sato J (1998) Effect of liftoff on NOx emission of turbulent jet flame in high-temperature coflowing air. The 27th International Symposium on Combustion, pp 1149–1155Google Scholar
- Ho CM, Tai YC (1996) Review: MEMS and its applications for flow control. ASME Int Fluids Eng 118:437–447Google Scholar
- Kurimoto N, Suzuki Y, Kasagi N (2001) Active control of coaxial jet mixing and combustion with arrayed micro actuators. In: Proceedings of the fifth World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Thessaloniki, pp 511–516Google Scholar
- Pitts WM (1988) Assessment of theories for the behavior and blowout of lifted turbulent jet diffusion flames. The 22nd International Symposium on Combustion, pp 809–816Google Scholar
- Su LK, Han D, Mungal MG (2000) Measurements of velocity and fuel concentration in the stabilization region of lifted jet diffusion flames. Proc Combust Inst 28:327–334Google Scholar
- Suzuki H, Kasagi N, Suzuki Y (1999) Manipulation of a round jet with electromagnetic flap actuators. In: Proceedings of the 12th IEEE International Conference on MEMS’99, Orlando, pp 534–540Google Scholar