The Analysis Of Movement Characteristics Of Single Bubble In Power Ultrasonic Honing Area

The main way of power ultrasonic honing is wet processing. Cavitation effect will beproduced in the process of machining honing area. The material removal rate and machiningprecision of workpiece will be effected by high speed micro-jet and shock waves when a largenumber of cavitation bubble collapse,which generated in cavitation.Bubble dynamics,bubblebreaking form, high speed micro-jet and shock waves was studied in this paper. The singlecavitation bubble in the grinding zone was the research object from the angle of the bubbledynamics and the processing of ultrasonic honing by the methods of cavitation dynamics,fluid dynamics and vibration theory using theoretical analysis, numerical simulation andexperimental verification tool in this reach. This will be provides a certain theoretical andexperimental basis for further research of the mechanism of ultrasonic honing.The papers main research work and conclusions are as follows:1.The dynamics equation of real gas single cavity was established in the grinding zoneby the introduction of van der Waals equation of constant volume and gravity parametersbetween the molecules.The single cavitation bubble in the grinding zone was the researchobject from the angle of the bubble dynamics and the processing of ultrasonic honing by themethods of cavitation dynamics, fluid dynamics and vibration theory in this equation.On thisbasis, the resonance frequency equation and the maximum pressure of empty bubble breakingequation was derived.2.The impact of ultrasonic frequency, cavitation initial radius, pressure amplitude andinitial phase on the law of cavitation bubble dynamics was analysised by using the Matlabsoftware. Simulation results: With increasing frequency ultrasound cavitation effect weakened, when the ultrasonic frequency is too large, no cavitation occurs; Cavitation effect wassignificantly when the initial radius in the order of10-1~101magnitude; With the decreaseof the amplitude of the sound pressure, cavitation weakened when cavitation is less than thethreshold, no cavitation occurs; Initial phase affects the initial pressure situation vacuoles,thus also have a greater impact to the cavitation.3.Single cavity was simulated in infinity field by using Fluent software VOF model.Simulation results: The vacuolus in the infinite far field shrinkage, expansion, oscillationfinally collapse due to the existence of the differential pressure. There were a large speedpulse and pressure pulses in the order of102m/sand101MPamagnitude in the process ofvacuoles breaking. And always achieve maximum speed first, then achieve maximumpressure. Caviation effect was significantly and the speed and pressure pulses were largerwhen the initial radius in the order of magnitude. The minimum value of thevacuoles relative volume was between0.2and0.3at that order magnitude in0.04timearound.4. Single cavity was simulated near solid wall by using Fluent software VOF model.Simulation results: Due to the existence of the rigid wall and the difference of the inside andoutside pressure, formed two small vacuoles,depression and penetrating to the rigid wall andformed a micro jet into the wall when the bubble collapsed. The bubble collapse time levelwas1s.The speed was in the order of102m/smagnitude. The pressure was in the orderof107Pamagnitude. Only the distance between the rigid wall and vacuoles inside the cavityradius may cause material damage because that the jet velocity decreased rapidly in liquid.There was a high-pressure pulsation in10M Pamagnitude in a very short period of time, candirectly cause the destruction of the material.5. The role of the microjets and shock pressure on the workpiece was studied by thealuminum foil corrosion method.