摘要:
运用光学Mie散射测量,实验研究了声致发光单泡的运动状态和发光光强受激励声场频率f及声压Pa变化的影响,结合动力学R-P方程拟合得到不同声压Pa下气泡半径随时间变化的动力学特征曲线——R(t)曲线,定量确定了气泡平衡半径R0和压缩比Rmax/R0,并通过气泡振子模型给出的势能方程估算了气泡塌缩阶段的能量损耗。结果表明:适当控制谐振频率(△f/f0~10-4,f0=21 kHz)和声压(1.2 atm~1.5 atm)可实现稳定的单泡声致发光;并且随着Pa的增大,气泡压缩比增大,回弹势能占总能量的比值逐渐减小(10-1~10-3),气泡在膨胀相聚集的大部分声能很可能以激波和热能形式释放。
Abstract:
The steady single-bubble sonoluminescence (SBSL) under the proper conditions of resonance frequencies △f/f0(~10-4, f0=21 kHz) and sound pressure Pa (1.2 atm~1.5 atm) at room temperature was successfully obtained. The sound pressure Pa-dependent dynamic behaviors of the bubble, including its radius versus time curve R(t), ambient radius R0, and the compression radio Rmax/R0, were investigated by fitting the Mie scattering measurement data to Rayleigh-Plesset equation. Meanwhile the energy dissipation of the bubble through rebound by calculating its potential energy was estimated. It is found that Rmax/R0 increased with Pa, while the ratio of bubble's rebound energy to its total energy decreased (10-1~10-3), which indicated that most energy of the bubble was transformed into thermal energy and/or generating the imploding shock wave.
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