Influence Of Gas Flow And Temperature On The Discharge Plasma And The Design Of Plasma Jet Device

During the operation of engines,improving combustion efficiency helps to reduce the amount of carried-fuel,Increase the payload,reduce the energy consumption and increase the flight distance of ships.The plasma ignition combustion technology can effectively improve the combustion rate of fuel,shorten the ignition time and improve the stability of flame.It is considered the most efficient auxiliary ignition method.Unlike conventional ground ignition,the discharge characteristics of aero engines will be changed due to their complicated operation conditions(wide temperature,low pressure and high speed flow),but the influence of temperature and airflow on the discharge characteristics of plasma is not clear.Therefore,the main purpose of this paper is to analyze the influence of temperature and airflow on the discharge characteristics of plasma,taking dielectric barrier discharge and plasma jet as the research object.And also designs a plasma jet ignition device with a plasma length of 1-10 cm.(1)It is found that with the increase of air flow rate,,the dielectric barrier discharge filament increases and the number of discharge pulses and the peak value of discharge current are also increased.With the increase of airflow temperature,the number of discharge increases significantly,but the peak value of current decreases.(2)It was found that the discharge length,discharge power and the peak value of discharge current increased significantly with the increase of gas flow rate.With the increase of airflow temperature,the number of discharge increased and the peak value of current decreased,which is consistent with the result of dielectric barrier discharge.(3)A comparative study of different electrode structure(needle-needle,needle-ring,needle-conical nozzle),we get a 10cm-long nitrogen plasma jet and 4-cm long air plasma jet.Injecting power and breakdown voltage and the increase in oxygen content have a great effect on plasma jet.In addition,it is found that the when the interaction between plasma jet and ceramic up to 60 s,It can significantly change the roughness and contact angle of ceramic surface,which is related to the formation of micron cone synapse on the surface of ceramic induced by plasma.