الفهرس 
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Abstract
The present study presents an experimental and numerical study of pulsating flame. The study is applied to clarify the effect of adding excitation to the inlet flow on combustion characteristics and reducing emissions.
The experimental test rig is designed to verify the effect of pulsating flow on temperature distribution and flame length through three cases:
• Effect of 15 l/m airflow pulsation with (o, 150, 900, 1800 rpm) on inverse diffusion.
• Effect of 30 l/m airflow pulsation with (o, 150, 900, 1800 rpm) on inverse diffusion.
• Effect of fuel pulsation with (o, 150, 900, 1800 rpm) on normal diffusion combustion.
The numerical study is applied using Ansys 16 commercial package through the following four cases.
• First, the effect of airflow pulsation at frequencies (100, 200, 300, 400 and 500) rad/sec on a 2D symmetric axis Harwell furnace is investigated. The chemical reactions of methane are numerically modeled using the eddy dissipation model, the detached eddy simulation model, and the P-1 radiation model. The effect of an air pulsation at a frequency of 500 rad/sec with excess air on the combustion flow parameters was presented. The obtained results were compared with the numerical results of Hosseini [1] to validate the numerical model.
• Second, the effect of a methane flow pulse having frequencies of 200 and 300 rad/sec on a 2D symmetrical combustion cylinder is demonstrated. One-step soot sub-model is selected. The numerical results obtained from normal diffusion combustion were compared with the experimental results produced by Garréton and Simonin [2] and numerically using Silva [3].
• Third, the effect of airflow pulsation in inverse diffusion combustion of LPG on a three-dimensional cylindrical chamber was shown. Non-premixed combustion model and a large eddy simulation are used.
• Fourth, the effect of mixing active and passive airflow control on the characteristics of inverse diffusion flame has been determined. Active control is applied using air pulsation and passive control is applied by changing the circular air nozzle to a square nozzle.
The main result of the studies demonstrated a significant reduction in the volume of a pulsating flame compared to a non-pulsating flame by 40%. The pulsating flow leads to a homogeneous temperature distribution along the combustion chamber. Increasing the Strouhal number increases the velocity of the combustion product and the turbulent kinetic energy. Excitation reduces CO, NOx and soot emissions by 50, 28 and 285%, respectively as minimum.