An Investigation Of Mechanism And Characteristics Of Frost Restraint By Coupling Surface Ultrasonic Wave With Low-Energy Wall

Frosting often occurs on the surface of filters of gas turbine and other oil and gas storage and transportation equipment in natural gas pipelines.In order to effectively inhibit the occurrence of frost,the mechanism and characteristics of frost restraint with surface ultrasonic wave coupled with low-energy surface are studied.An improved enthalpy-based lattice Boltzmann model for simulating the phase transition process is proposed based on the frost restraint mechanism of super-hydrophobic surface.The simulation results show that the contact angle of surface and the rough elements affect the freezing process of the droplet.An improved enthalpy-based lattice Boltzmann model with nucleation probability function is used to simulate the growth process of frost layer on cold surface.The simulation results show that frost growth can be inhibited by increasing cold surface contact angle,increasing cold surface temperature and decreasing wet air relative humidity.Based on the mechanism of ultrasonic waves,the multi-relaxation lattice Boltzmann model is used to simulate the ultrasonic wave propagation and the droplet movement on the lowenergy surface.The simulation results show that there is attenuation phenomenon in the process of ultrasonic propagation.The droplet on the super-hydrophobic surface is easier to be removed.The shorter the wavelength of the ultrasonic wave,the easier it is for the droplet to leave the surface.The larger the amplitude of surface ultrasonic wave,the farther the droplet moves.In addition,the freezing processes of the droplet and the melting processes of the frozen droplet with ultrasonic wave propagating along the low-energy cold surface are simulated.The simulation results show that the shorter the wavelength of ultrasonic wave on the surface,the later the freezing time of the droplet is.In the heat absorption process,the completely frozen droplet also melts.The larger the amplitude of surface ultrasonic wave,the farther the ice particles move.The method of coupling surface ultrasound with low-energy surface is presented,which provides a new idea for future research on frost restraint.