- 會議論文
Sound Field Prediction in Long Enclosures with Branches
封閉長空間中具有不同型式分支之聲場預測
摘要
The propagation of sound in long enclosures with branches has been studied theoretically and experimentally, and an efficient combined method is proposed to predict the sound field in long enclosures with branches. Based on the wave-acoustics theory, the theoretical analysis of the sound field of the long enclosures with branches is performed. This paper also investigated the sound field prediction of long enclosures with branches, by using the acoustic modeling program, ODEON. The results obtained by the theoretical analysis and the numerical simulation ODEON are compared with the experimental measurements, and the characteristics of the two methods for predicting the sound field of long enclosures with branches are analyzed. Compared with the experimental results, it is found that: 1) the results predicted by the theoretical analysis fluctuate relatively large with respect to the source-receiver distance, and the sound pressure level (SPL) attenuation obtained is smaller than that measured; and 2) the results predicted by the numerical simulation is smoother, and the calculated SPL attenuation is larger than that measured. To effectively predict the sound field of long enclosures with branches, a combined numerical method is thus proposed. The effectiveness of the proposed combined method is demonstrated by the scale-model experiments.
並列摘要
從理論上和實驗上研究具有不同型式分支之封閉長空間之聲場的傳播，並提出了一種有效的組合方法來預測帶有分支的封閉長空間中的聲場。基於波聲理論，研究對有分支的封閉長空間的聲場進行了理論分析。本文還利用聲學建模程序ODEON研究了具有分支的封閉長空間的聲場預測。將理論分析和數值模擬ODEON得到的結果與實驗測量結果進行對比，分析這二種預測方法的特點。與實驗結果相比，發現：（1）理論分析預測的結果相對於音源－接收點距離波動較大，所獲得的聲壓級（SPL）衰減小於測量值；（2）數值模擬預測的結果更平滑，計算的SPL衰減大於測量值。為了有效地預測具有分支的封閉長空間的聲場，因此提出了組合數值方法。通過比例模型實驗證明了所提出的組合方法對減噪有效。