近场超声悬浮启浮瞬态行为的理论分析及实验测试

超声悬浮气膜瞬态行为的认识对悬浮体运动规律及悬浮精度控制等都有着重要作用。运用气体动力学理论研究超声挤压问题,建立了自由悬浮体瞬态气膜压力及其非线性动力学模型.应用数值方法对模型进行求解,获得超声激励下气体挤压膜在启浮过程中的瞬态压力分布、承载能力以及悬浮盘位移的变化规律。分析发现激励盘振幅、频率等参数对启浮过程的瞬态行为有着显著的影响,激励盘振幅越小、激励频率越高,启浮过渡过程达到稳态所需时间越长。在理论分析的基础上还对瞬态启浮过程进行实验研究,应用激光位移传感器对瞬态悬浮位移进行测试,发现理论分析和实验测试结果一致性较好。 

Research on the transient behavior of near field ultrasonic levitation during lifting up

Research on the transient behavior of ultrasonic squeeze film is very important for the understanding of the movement and the controlling precision of levitating object. The present paper study the transient behavior of ultrasonic squeeze film by the use of aerodynamic theory, built up the models of free levitating disk on the squeeze gas film and the dynamic equation, and then the models solved by value methods. The pressure distribution, load capacity of squeeze film and the displacement of suspending disk are obtained. The results show that exciting amplitude and frequency have a significant effect on the transient behavior during the levitating period, the smaller amplitude, the longer the time to reach its stable position, the excitation frequency have the same effects too when the exciting frequency becomes higher. An experimental study has been carried out on the basis of theoreticM analysis, the displacement of the suspending disk is measured by a laser displacement sensor, and it shows a good agreement with the theoretical results.