Design And Research On Flow Field Of Gas-liquid Coaxial Self-excited Oscillating Atomization Nozzle

Self-excited oscillating atomization is a new type of atomization in the field of atomization currently.It has the characteristics of no need of excitation energy.Its unique self-excited oscillating chamber is capable of converting continuous jet flow into pulsed jet flow.The atomization nozzle affects the quality and efficiency of atomization directly.Currently,only single-phase self-excited oscillating atomization nozzle has been studied.Analysis of flow field of multiphase self-excited oscillating atomization nozzle is lacking.In this paper,a new method of atomization is proposed based on the research of self-excited oscillating atomization nozzle--gas-liquid coaxial self-excited oscillating atomization.A kind of gas-liquid coaxial Self-excited oscillating atomization nozzle was designed.Taking the gas-liquid coaxial Self-excited oscillating atomization nozzle as the research object,the influence of the internal flow field and the working conditions on the jet performance of the nozzle was analyzed by numerical simulation.The main research contents are as follows:(1)A new method of atomization of gas-liquid coaxial self-excited oscillating was proposed.On the basis of the structure of conventional self-excited oscillating atomization nozzles and in order to reduce the effect of gas jet on the cavitation of liquid jet to ensure the self-excited oscillating effect of the nozzle chamber,a kind of gas-liquid coaxial self-excited oscillating atomization nozzle was designed.And the key structural parameters of the atomization nozzle was identified.(2)Two finite element models of gas-liquid coaxial self-excited oscillating atomization nozzle and conventional self-excited oscillating atomization nozzle were established.Flow field phase,static pressure on outlet axis,speed on outlet axis,average static pressure on outlet,average speed on outlet and liquid field of internal flow were calculated.Jet oscillating effect,oscillating intensity,disturbance of flow field and the effect of energy accumulation and release of gas-liquid coaxial self-excited oscillating atomization nozzle were analyzed.(3)The influence of different working conditions on the internal flow field of gasliquid coaxial self-excited oscillating atomization nozzle was studied.The flow characteristics of the nozzle were analyzed from the gas inlet boundary condition and theliquid inlet boundary condition in turn.The conditions that can produce better atomization effect were obtained.