Experimental Research On The Effect Of The Process Parameters Of Aerosol Mist Cooling Of Focused Ultrasound On The Heat Transfer In The Grinding Zone

In the process of grinding, because of the high speed of grinding wheel, the air flow field is formed around the grinding wheel. The "gas barrier" produced by the air flow field will hinder the effective injection of grinding fluid, which can affect the cooling effect in grinding process, and the workpiece can not be cooled effectively.Therefore, the ordinary cooling method is difficult to meet the cooling demand of grinding process.The key to realize effective cooling of the grinding zone is to provide enough driving force for the grinding liquid, so that it can overcome the resistance of the air layer and achieve the grinding zone successfully. Based on the sonodynamic effect of the focused ultrasound, and steam fog medium has strong ability of heat transfer. The research group use the focused ultrasound steam fog cooling to cool the grinding zone, to explore the influencing rule of focused ultrasound mist cooling on grinding temperature.Using the ideas of heat transfer enhancement in the thermal field, to explore the ability of the heat exchange capacity. By changing the voltage of the heating plate, we get a series of corresponding equilibrium temperature, then we calculate the heat flux and heat transfer coefficient. We found that the heat transfer coefficient is stronger than the ordinary water jet cooling, The focusing device can enhance the heat transfer ability effectively. And the higher the temperature is, the more advantage of the focused ultrasound mist cooling can be reflected.To do grinding experiment, the first process parameter should be studied is the position of the nozzle. When the nozzle position is different, the quantity and manner of steam fog enter the grinding zone will be different, which can lead to different heat transfer effect. By changing the horizontal distance between nozzle and the grinding wheel center, the angle between nozzle between the workpiece surface and the vertical distance between nozzle and the workpiece surface,to explore the change rules of grinding temperature in different positions. The experimental results show that, the closer the horizontal distance betweennozzle and the grinding wheel center is, the better the effect of heat exchange is;When the surface of the nozzle and the workpiece has a certain angle, the heat exchange effect is better than the horizontal situation. Because when the distance between nozzle and the grinding zone is closer, the ability of steam fog to break through the airflow field around the grinding wheel is stronger, more cooling liquid will enter the grinding zone.Select the appropriate position of nozzle, then do grinding experiment. First of all, as a contrast,do grinding experiment without cooling liquid; In the condition of aerosol mist cooling of focused ultrasound, By changing the amount of steam, to explore the variation rules of grinding temperature when the amount of steam fog is different. And compared grinding temperature when the atomizer has not focusing device. We found that the most significant factor that affect grinding temperature is grinding depth. Aerosol mist cooling of focused ultrasound can reduce grinding temperature in the grinding zone greatly. The ability of heat transfer become stronger when the amount of steam fog is increased. The ability of heat transfer become stronger obviously when the atomizer has focusing device under the condition of the same amount of steam fog.