Sojahrood A J, Haghi H, Karshafian R, Kolios M C
Department of Physics, Ryerson University, Toronto, Canada; Institute for Biomedical Engineering, Science and Technology (IBEST) a partnership between Ryerson University and St. Mike's Hospital, Toronto, Ontario, Canada.
Department of Physics, Ryerson University, Toronto, Canada; Institute for Biomedical Engineering, Science and Technology (IBEST) a partnership between Ryerson University and St. Mike's Hospital, Toronto, Ontario, Canada.
Ultrason Sonochem. 2020 Sep;66:105089. doi: 10.1016/j.ultsonch.2020.105089. Epub 2020 Mar 24.
Current models for calculating nonlinear power dissipation during the oscillations of acoustically excited bubbles generate non-physical values for the radiation damping (D) term for some frequency and pressure regions that include near resonance oscillations. Moreover, the ratio of the dissipated powers significantly deviate from the values that are calculated by the linear model at low amplitude oscillations (acoustic excitation pressure of P=1 kPa and expansion ratio of <≊1.01). In high amplitude oscillation regimes (P⩾20 kPa), the dissipated power due to D deviates largely from the dissipated power as calculated by the widely accepted approach that uses the scattered power by the bubbles. We provide critical corrections to the present models. The validity of the results was examined in regimes of low amplitude oscillations and high amplitude oscillations. In the low amplitude regime, the ratio of the dissipated powers as calculated by the current and proposed model were compared with the linear model predictions. At higher amplitude oscillations, the dissipated power by radiation loss as calculated by the current and the proposed models were compared with the dissipated power calculated using the scattered power by the bubbles. We show that non-physical values are absent in the proposed model. Moreover, predictions of the proposed approach are identical to the predictions of the linear model and the dissipated power estimated using the scattered pressure by the bubble. We show that damping due to thermal effects, liquid viscosity and radiation heavily depend on the excitation pressure and that the linear model estimations are not valid even at pressures as low as 20 kPa.
当前用于计算声学激发气泡振荡过程中非线性功率耗散的模型，对于某些频率和压力区域（包括近共振振荡）的辐射阻尼（D）项会产生非物理值。此外，在低振幅振荡（声学激发压力P = 1kPa且膨胀比<≊1.01）时，耗散功率的比值与线性模型计算的值有显著偏差。在高振幅振荡状态（P⩾20kPa）下，由D引起的耗散功率与使用气泡散射功率的广泛接受的方法计算出的耗散功率有很大偏差。我们对当前模型进行了关键修正。在低振幅振荡和高振幅振荡状态下检验了结果的有效性。在低振幅状态下，将当前模型和所提出模型计算的耗散功率比值与线性模型预测值进行了比较。在较高振幅振荡时，将当前模型和所提出模型计算的辐射损失耗散功率与使用气泡散射功率计算的耗散功率进行了比较。我们表明所提出的模型不存在非物理值。此外，所提出方法的预测与线性模型以及使用气泡散射压力估计的耗散功率的预测相同。我们表明，热效应、液体粘度和辐射引起的阻尼严重依赖于激发压力，并且即使在低至20kPa的压力下，线性模型估计也无效。
