Effects of Jet Flow Pulsation on Diffusion Flame Performance
A.M. Moustafa1, M.M.Kamal2, Ashraf M. Hame
d3, Ahmed E Hussin4
1A.M. Moustafa, Professor, Department of Mechanical Power, Ain Shams University, Egypt.
2M.M.Kamal, Assistant Professors, Faculty of Engineering, Ain Shams University, Egypt.
3Ashraf M. Hamed, Assistant Professors, Faculty of Engineering, Ain Shams University, Egypt.
4Ahmed E Hussin, Assistant Professors, Faculty of Engineering, Ain Shams University, Egypt.

Manuscript received on October 06, 2020. | Revised Manuscript received on October 25, 2020. | Manuscript published on November 30, 2020. | PP: 444-451 | Volume-9 Issue-4, November 2020. | Retrieval Number: 100.1/ijrte.D5031119420 | DOI: 10.35940/ijrte.D5031.119420
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: The objective of the current research is the experimental investigation of the pulsating flow effects on the combustion performance in terms of the flame temperature distribution, the heat transfer rate, the combustion efficiency and the exhaust gas analysis. The flow pulsation provided through a rotary ball valve in accordance with a variable speed motor arrangement increased the flame temperature fluctuation and the magnitude of heat release. The flow pulsation provides a highly turbulent flame wherein the vortices are enlarged. Increasing Strouhal number [St] of the LPG fuel and air flow increases the time-averaged flame temperature of the pulsating flame up to a saturation level that is dictated by the heat transfer rate enhancement. The maximum average flame temperature is 1263oC at St= 0.041, r= 0 mm and 100 mm from the burner inlet. In addition, increasing the pulsating flow amplitude increases the convection and radiation heat fluxes from the pulsating flame. While increasing the pulsation decreases the exhaust UHC due to increasing the turbulent kinetic energy across the pulsating flame, the exhaust NOx slightly increases due to increasing the heat release rate and the flame temperatures. Pulsation thus enhances the combustion efficiency inside the industrial combustors. 
Keywords: External pulsation, pulsating flame, Inlet flame port, Diffusion flame, Pulsation frequency, pulsator combustor.