热探针法测量超声场强度分布

Ultrasound intensity distribution measur ement using a thermoelectric probe

采用热探针法测量了探头式超声设备在纯水中的一维和二维声场强度分布,探究超声强化化工过程的机理.声场强度随着轴向和径向距离的增加而衰减,并满足声场的衰减方程.由于器壁的反射,在轴向和径向产生了驻波.通过构建二维声场强度分布图,考察了超声频率、超声电功率对声场强度分布的影响,并观测了超声探头下方形成的气泡云.结果表明,不同频率下,40 kHz下的声场强度高于30 kHz;同一频率下,超声电功率对声场强度的影响较小,探头下方气泡云的屏蔽作用是电功率影响较小的原因.

A thermoelectric probe was used to measure the one-dimensional and two-dimensional ultrasound intensity distribution of an ultrasound horn in homogeneous water systems. This allowed the mechanism of the ultrasound enhanced chemical process to be obtained. The intensity attenuated as the distance increased in the axial and radial directions, which was in accordance with the standard attenuation function. As the reflection of a flask wall, stand- ing waves were formed at the axial and radial directions. The effects of ultrasound frequency and ultrasound electric power on ultrasound intensity distribution were investigated by constructing two-dimensional ultrasound intensity distribution images. A bubble cloud was formed around the horn tip. The results indicate that the intensity at 40 kHz is higher than at 30 kHz. While under the same frequency, the influence of electric power on ultrasound intensity is slight because of the shielding of the bubble cloud.