Affiliation:
1. Department of Aircraft Engineering, Air Force Institute of Technology, Kaohsiung, Taiwan 820, China e-mail:
2. Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung, Taiwan 202, China
Abstract
The target of this study is to promote combustion capability using a novel rifled nozzle which was set at the outlet of a conventional (unrifled) combustor. The rifled nozzle was utilized to adjust the flow swirling intensity behind the traditional combustor by changing the number of rifles. The rifle mechanism enhances the turbulence intensity and increases the mixing efficiency between the central-fuel jet and the annular swirled air-jet by modifying the momentum transmission. Specifically, direct photography, Schlieren photography, thermocouples, and a gas analyzer were utilized to document the flame behavior, peak temperature, temperature distribution, combustion capability, and gas-concentration distribution. The experimental results confirm that increasing the number of rifles and the annular swirling air-jet velocity (ua) improves the combustion capability. Five characteristic flame modes—jet-flame, flickering-flame, recirculated-flame, ring-flame and lifted-flame—were obtained using various annular air-jet and central fuel-jet velocities. The total combustion capability (Qtot) increases with the number of rifles and with increasing ua. The Qtot of a 12-rifled nozzle (swirling number (S) = 0.5119) is about 33% higher than that of an unrifled nozzle. In addition, the high swirling intensity induces the low nitric oxide (NO) concentration, and the maximum concentration of NO behind the 12-rifled nozzle (S = 0.5119) is 49% lower than that behind the unrifled nozzle.
Subject
Mechanical Engineering,Energy Engineering and Power Technology,Aerospace Engineering,Fuel Technology,Nuclear Energy and Engineering
Reference24 articles.
1. A Swirling Round Turbulent Jet 1-Mean-Flow Measurements;ASME J. Appl. Mech.,1962
2. Velocity and Static Pressure Distributions in Swirling Air Jets Issuing from Annular and Divergent Nozzles;ASME J. Fluids Eng.,1964
3. Davies, T. W., and Beer, J. M., 1971, “Flow in the Wake of Bluff-Body Flame Stabilizers,” Proceedings of the Thirteenth Symposium (International) on Combustion, Salt Lake City, UT, August 23–29, 1970, The Combustion Institute, Pittsburgh, PA, pp. 631–638.10.1016/S0082-0784(71)80065-6
4. Flame Lift-Off and Stabilization Mechanisms of Nonpremixed Jet Flame on a Bluff-Body Burner;Combust. Flame,1998
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