Study on the real-time variation laws and mechanism of oil sample viscosity during ultrasonic irradiation

Abstract

It is rather significant to reveal the real-time variation of oil sample viscosity during ultrasonic irradiation to research the mechanism of viscosity change. In this paper, we first simulate the acoustic field distribution law in the reaction chamber by using the finite element method and orthogonal experiment method, then measure the viscosity of the oil sample with temperature by vibration type viscometer and get the corresponding function equation by fitting. On this basis, we measure the viscosity of the oil sample with ultrasonic irradiation time and electric power change in real-time and in situ, and finally analyze the mechanism of oil sample viscosity variation by using a temperature recorder and cavitation noise method. The results show that the greatest influence on the acoustic pressure in the reaction chamber is the change of the transducer probe in the height Z direction, followed by the width X direction and the depth Y direction. The viscosity of the oil sample shows an exponential decay with the increase in temperature. With the increase of ultrasonic irradiation time and electric power, the viscosity of the oil sample is gradually reduced. By comparing the effect of heating and ultrasonic irradiation on viscosity, it is found that ultrasonic irradiation not only changes the viscosity through thermal effect but also the cavitation noise analysis and the phenomena observed in the experiment confirm that the cavitation effect and mechanical effect exist all the time.

Keywords

• Ultrasound
• Real-time measurements
• Viscosity variation mechanism
• Acoustic cavitation
• Finite element simulation
• Orthogonal experiment