Experimental Research On Dual-source Coupled Plasma Ignition Technology

As the aviation aircraft in high altitude and other extreme conditions,there will be problems like ignition difficulties,the engine flameout and so on,plasma enhanced ignition technology already becomes an important research hotspot.At present,the plasma ignition mainly uses its thermal effect to strengthen the ignition,while ignoring the effect of chemical reaction power effect.But from the view of the mechanism of plasma ignition,the role of non-equilibrium plasma in plasma ignition process is equally critical and deserves a thorough study.Therefore,this paper has carried out the following research work on the dynamic effect of chemical reaction in plasma ignition:The operating characteristics of dual-source coupled plasma igniter are studied by using self-designed plasma igniter and dual-source coupled power supply.It is proved that the dual-source coupling excitation has a stable arc effect and can produce more non-equilibrium plasma,which can effectively improve the total efficiency and can reduce the ablation of the electrode and prolong the life of the igniter.By changing the turns ratio of DC source current to pulse source,the effect of the mechanism of dual source excitation plasma is discussed.The results show that the current mainly controls the equilibrium plasma,while the pulsed source mainly controls the non-equilibrium plasma.The pulse source is coupled to the DC source to form a dual source excitation which can effectively reduce the plasma thermal effect and improve the chemical power effect of the non-equilibrium plasma.Based on self-designed plasma igniter,a central ignition mechanism test platform was designed,and the ignition characteristics of dual source excited plasma igniter were studied.It is found that the dual-source excitation plasma igniter can effectively broaden the ignition boundary,shorten the ignition delay time and improve the combustion efficiency.By changing the turns ratio of DC source current to pulse source,the effect of the mechanism of dual-source excited plasma ignition is discussed.The results show that the current heat effect in the dual source coupling provides the heat for the plasma ignition,and the pulse rising rate dominates the chemical dynamic effect,which provides the non-equilibrium plasma for the plasma ignition,and the two cooperate to improve the ignition quality.According to the conclusion of experiments,the self-designed plasma igniter is applied to the standard turbojet combustion chamber and the scramjet enginecombustion chamber.The results show that the dual source coupled plasma igniter can effectively broaden the ignition boundary and improve the combustion efficiency.It is proved that the dual-source coupled plasma can improve the energy ratio and the energy efficiency.All of above show that the dual-source coupled plasma igniter has practical application value.