Research On Directivity Of Binary Ultrasonic Transducer Array

Ultrasound is a sound wave with a frequency higher than the upper limit of the audible limit of human hearing,with a frequency of 20 kHz to several gigahertz.Ultrasound has three distinct features.Ultrasonic waves have a high frequency,so the directivity of ultrasonic propagation is very strong and can penetrate almost all materials;The particles in the medium produce a large acceleration during ultrasonic propagation;When the ultrasonic wave propagates in the liquid,if the sound intensity reaches a certain threshold,cavitation will occur.Ultrasonic cavitation refers to the process from the appearance of bubbles in the liquid to the process of breaking when the ultrasound propagates through the liquid.There is a threshold for ultrasonic cavitation.Ultrasound is used in many fields.Ultrasonic equipment is used to measure distance in water.Industrially,ultrasonics are used for cleaning,as well as mixing and accelerating chemical processes.In the non-destructive testing of products and structures,ultrasonic waves are used to detect defects that are not visible therein.Ultrasound imaging and ultrasound therapy are commonly used in medicine.Ultrasonic transducers are acoustic sensors that fall into three broad categories: transmitters,receivers,and transceivers.The transmitter converts the electrical signal into ultrasonic waves,the receiver converts the ultrasonic waves into electrical signals,and the transceiver can transmit and receive ultrasonic waves.Ultrasonic transducers are capable of generating ultrasound,but a single ultrasound transducer typically does not meet the multifaceted requirements of practical applications,and it is often necessary to utilize an array of ultrasound transducers to meet these requirements.At present,domestic and foreign research is mainly focused on a single type of ultrasonic transducer array as an array element,and there is little research on a variety of ultrasonic transducers as an array element.Therefore,the circular piston transducer and the rectangular piston transducer are used together as the basic elements of the ultrasonic transducer array.This paper first introduces the definition of the sound field characteristics and directivity of the transducer.Next,the sound field characteristics and directivity of the circular piston transducer and the square piston transducer in the far field are introduced and simulated.Finally,the sound field characteristics and directivity of the transducer array are introduced,and the multiplication theorem and addition theorem are expounded.The research content of this paper is divided into two parts.The first part is to calculate the change in the directivity of the transducer array caused by their change by changing the arrangement of the transducer arrays.Firstly,several arrangements of a 3×3 transducer array composed of a single array element and several arrangements of a 3×3 transducer array composed of two array elements are illustrated,and the directivity of the array is calculated and simulated.The results show that the largest side lobes of an ultrasound transducer array consisting of two array elements are the smallest of several arrangements.Therefore,a 3×3 transducer array composed of two array elements can be better in directivity than a 3×3 transducer array composed of a single array element.Several arrangements of a 4x4 transducer array consisting of a single array element and a 4x4 transducer array consisting of two array elements were then investigated.Finally,several arrangements of a 5×5 transducer array composed of a single array element and a 5×5 transducer array composed of two array elements were studied.A similar conclusion was reached.Therefore,a transducer array employing two array elements can be better in directivity than a transducer array using a single array element.The second part is to change the parameters of the transducer array composed of two array elements to calculate the change of the directivity of the array caused by their change.The directivity of the transducer array composed of two elements with different spacing is calculated.The research results show that the smaller the array element spacing,the better the directivity of the transducer array of the two array elements.By calculating the directivity of transducer arrays of two elements with different element sizes.The results show that the larger the element size,the better the directivity of the transducer arrays of the two elements.The directivity of transducer arrays of two elements with different element frequencies is calculated.The results show that the higher the ultrasonic frequency is,the better the directivity of the transducer arrays of the two elements is.The directivity of transducer arrays with two elements in different media is calculated.The results show that the smaller the sound velocity in the medium,the better the directivity of the transducer arrays of the two arrays.