非整数维超声相控阵探测方法研究

研究了非整数维超声相控阵聚焦特性以及在石油井下的扫描探测方法,首先对1.25D,1.5D和1.75D相控阵聚焦声场进行了分析.对如何提高仰角方向分辨率及减少动态阵元数等问题进行了深入的讨论;然后,研究了环形和分割环形相控阵列聚焦声场及声束偏转等特性,并和2D面阵进行了对比分析;论文还对1.25D, 1.5D、1.75D、环形和分割环形相控阵列在石油测井中的应用方法进行了研究和讨论,为超声相控阵技术在井下应用提供了理论基础.     

Radiation Acoustic Field of a Linear Phased Array on a Cylindrical Surface

A new linear ultrasonic phased array fixed on a cylindrical surface is designed. This kind of the cylindrical phased array can meet the specific requirements of the application in testing pipe quality inside pipes. Using the transducer, we can not only avoid mechanical rotating but also test the quality of any point in a pipe by ultrasonic phase array technology. The focused acoustic field distributions in the axial, radial and tangential directions of the transducer are investigated theoretically by numerical simulation. The energy flux density, the width of the main lobe, the imaging resolution, the grating lobe elimination and other characteristics are analysed. The effect of the focal distance, effective aperture, transducer radius, number of total element, and steering angle on the acoustic field distribution is also studied.thoroughly. Many important results are obtained.