Study On Charge And Motion Of Amorphous Carbon Particles Under Electrostatic Field

The carbon deposition which is widely existing in the internal combustion engine is also a big trouble for the aircraft engine.In some special operating conditions,oilrich areas will inevitably appeared in the engine combustion chamber,the carbon smoke particles which generate from incomplete combustion of hydrocarbon fuels is the main causes of carbon deposition.The existing defocusing methods have more or less negative effects on the stable operation of the aircraft engine,can not fundamentally solve the problem of carbon deposition.Therefore,it is very important to explore a new method which not only have no effect the performance of the engine,but also could perform online removal of carbon accumulation.The electrostatic field can produce a force on a charged object,otherwhise,it can also give a certain amount of charge to an object which is originally electrically neutral by means of field charge.Therefor,charged soot particles in the electric field are difficult to reach the nozzle wall.Electrostatic defocusing is expected to be the most effective means of defocusing,which has great application prospect and research value.However,the research on the use of electrostatic fields to remove carbon accumulations is still in infancy,in this paper we will explore this field from following aspects.First of all,amorphous carbon particles is used as experimental object.which is the main components of soot particles,and then the experimental system for the charge characteristics of particles is built for the study of the Charging characteristics of amorphous carbon particles.The influence of electric field parameters and flow field parameters on carbon particle charge has been analyzed.The electric field parameters include the operating voltage and the non-uniformity of the electric field,and the flow field parameters include the temperature and particle concentration.In addition,the discharge characteristics of Corona electric field under different working conditions are analyzed,in order to explain regulation of influence of environmental parameters on particle charge.Secondly,a visualizing experimental system for transport and transportation of charged granules was built based on the experimental system of charging characteristics of particles.With the help of the PIV system,the motion characteristics of charged and non-charged granules during Transport has been studied.Under the condition that the gas flow rate,particle concentration and temperature are guaranteed,the average charge of the particle group is changed by adjusting the operating voltage of the charge device,and the movement of the particle group under different charges is analyzed.Finally,a suitable electric field control equation and a particle charge mathematical model are selected to simulate the charge process of amorphous carbon particles in the electric field.Based on the previous experimental results,the dielectric properties of the continuous phase and discrete phase are corrected.The change of charge and position of amorphous carbon particles in electric field under different operating voltage,gas flow rate and particle size is analyzed.