Investigation Of High Intense Acoustic Array Technology In Ideal Medium

In this paper, the performance of high intense sound energy generator and sound energy generator arrays is numerically and experimentally studied. The whole work are listed as below:Experiments of liquid powered sound energy generators were carried out. The jetting pressure of gas, the width of the gap of the nozzle, the outer diameter of nozzle and the distance between nozzle and resonant pip were all studied to find out the influence on the performance of the air sprayed high intense sound energy generator. The frequency response feather of sound energy generator system on the air modulated high intense sound energy generator was also studied. Results show that the high intense sound energy generator with an inter diameter of 40mm has an optimal jet pressure value of about 9 atmospheric pressure, optimal width value of the gap of the nozzle as six millimeters and a optimal outer diameter value of nozzle as thirty three millimeters. The optimal point of frequency response lies between 500Hz and 600Hz.Numerical simulation models of the sound energy generator were set up according the theory of Boundary Element Method (BEM). Then these models were used in the numerical simulations of the sound fields of the generators and the arrays. The sound fields of the single generator, the array of two elements, the line array of four elements and the square array of four elements were numerically simulated. The influence on array performance due to the distance between elements, the phonate frequency, the number of the elements and the differences among elements were also simulated. Results show that under ideal conditions, the square array of four elements has the highest sound pressure level (SPL) in the symmetrical axis and the best directivity of sound field. The line array of four elements is similar to the square one, but if the sound absorption is considered, the square array of four elements is better. The angle of the main lobe decreases and the number of side lobes increases as the increase of the distance between elements and the acoustic frequency, but the SPL remains steady. When consider the sound absorption, the energy in the sound field becomes more divergent as the distance between element becomes lager, and the less energy lies in the direction of the main lobe. The higher frequency leads to the faster energy attenuation. The increase of the element number can enhance the directivity of the sound field and limit the increase of the number of the side petal at the same time. Slight difference of acoustic frequency and primal energy between elements has little influence to the whole sound field.The performance of the air jetted high intense sound energy generator array and the air modulated high intense sound energy generator array were experimentally studied, and the gain of SPL in the symmetrical axis of horn and the orientation of sound field were analyzed. The results show that the increment of SPL in the symmetrical axes of horn and the directivity of sound field of the air modulated high intense speaker were both similar to the theoretical and numerical results.