Molecular dynamics simulation of droplet evaporation in a one-dimensional standing wave acoustic field

Experimental Study of Evaporation Characteristics of Acoustically Levitated Fuel Droplets at High Temperatures

“…The squares filled with different colors and connected by dotted lines represent the average evaporation rate of the droplets at various temperatures. The periodic oscillation of ultrasound waves [36] causes droplets to variously move with time in three-dimensional space, thus decreasing droplet surface area oscillations, as shown in Figure 5. Therefore, the mean evaporation rate at a constant state is chosen and computed as the evaporation rate (Equation ( 7)).…”

Evaporation issues of acoustically levitated fuel droplets

“…The equilibrium position is below a pressure node in the ultrasound field [35] , [61] , [62] . Fluid particle oscillations, which are the essence of sound waves, indicate that the mode of ultrasound wave propagation varies in each particular medium [11] , [21] . It is also worth knowing that, due to fewer molecules moving in liquids with high viscosity, there is a negative relationship between the acoustic wave strength and the liquid viscosity [21] .…”

“…The ultrasonic waves evoke the surrounding gas to vibrate, encouraging the mixing of vapor and oxidizer and accelerating the liquid droplet evaporation and combustion processes [6] , [90] . Recently, in [11] , the influence on droplet evaporation of acoustic wave oscillation and frequency was numerically discussed, but some results could not be fully explained.…”

“…A molecular dynamics (MD) technique for acoustically levitated water droplet evaporation and binary mixture evaporation was reported by Luhao Liu [11] (2023), where a standing acoustic wave was introduced to simulate an oscillation environment. The influences of amplitude and frequency were presented, but some simulated experimental results are not well explained.…”

“…In automobile, aircraft, and rocket engines, where there is forced convection, oscillating pressure and high temperatures, droplet evaporation becomes more complex, which is critical to form flammable mixtures for subsequent combustion. Therefore, it is essential to understand the droplet evaporation characteristics to enhance power performance and decrease pollutant emissions [6] , [7] , [8] , [9] , [10] , [11] .…”