Numerical simulation of the effects of gas temperature and particle density on particle dynamics in acoustic field

Dynamical model of a particle in an acoustic field was established.The viscous force,Basset force,virtual mass force,and pressure gradient force were included in the force model.The forces acting on the particle and the motion of the particle were numerically simulated using a variable time-step fourth-order Runge-Kutta method combined with the second-order implicit Adams interpolation method.The motion behaviors from numerical simulation were compared with those from the experiments to validate the simulation methods.On this basis,the effects of the gas temperature and particle density on the particle dynamics were examined.The results show that the viscous force dominates the particle motion.As the gas temperature increases,the phase difference between the pressure gradient force and the viscous force decreases,while those between the Basset force as well as virtual mass force and the viscous force increase.It is also found that when the gas temperature is low,the particle density affects significantly on particle motion.In this case,as the particle density increases,the entrainment coefficient decreases rapidly.Less dependence of the particle motion on the particle density is observed when the gas temperature is higher.Both the particle displacement amplitude and the entrainment coefficient increase obviously in case of a high temperature relative to a low temperature.