장방형 공연장의 음향시뮬레이션 과에 영향을 미치는 매개변수에 관한 연구

Abstract

A Study on the Parameters that Influence Acoustic Simulation Results of the Rectangular Hall

Tae-Hoon, Kim

Interdisciplinary Program of Acoustic and Vibration Engineering, The Graduate School, Pukyong National University

Abstract

In domestic, many multi-purpose halls have to face a lot of problems on the field of indoor sound, which is wrong from the beginning of architectural acoustic design at some level. There are some reasons what are not known, such as the limitations and problems of acoustic simulation programs. It has some relations with the above problems why appears error on the accuracy of the simulation. In addition, if the shape of the target architecture is simple and not complicated. The more simple space it is, the better consistency between predicted values and actual values it gets. On the contrary, in the case of complicated shape, it is difficult to input the whole data accurately. Then the information of the architecture is not sufficient so that many errors will certainly come out further. After setting all the acoustic design condition on the hall with walls and ceilings of the rectangular sound source. Through the results between measurements and simulation errors, it can be confirmed that available parameters are appropriate roles to cause the errors, such as the space around fixed seats and the slope of 10 degree or less, etc. It shows that the specific points error between measurement results and predictional results, average RT60 is +0.08 sec, D50 is 7.4%, C80 is 0.0 dB, which is considered by the prediction·measurement·analysis result due to the influence made by the simulation errors of the available superficial area on the hall with rectangular sound source. Moreover, the modeling shape about the ceiling, walls, chairs and seats almost have no relations with the final error, which can use the simple model to instead of the complicate ones to do the analysis. There are few errors occurred in RT60. The reason is that the difference between interior model and hall actual condition is small, due to relatively small effect on interior model with the rectangular sound source for the sound reflection and diffusion. So the reverberation time between the simulation and measurement is almost same. Using the model in details with interior superficial area in the case of rectangular sound source, it can be generalized that although the consistency between the measurements and simulations of RT60 and RATSI is very good, the one of D50 and C80 is far from perfect. That is because RT60 and RASTI are the macroscopic parameters and D50 and C60 are the microscopic parameters. This paper has confirmed that microscopic parameters is not good for the consistency between the measurements and simulations in conclusion. The macroscopic parameters can make an accurate prediction for the simple interior structure like rectangular sound source. However, it is difficult to input the data accurately and many errors will occurs in the consideration especially in the complex shapes and space, such as music hall and theater, ect. Using a real acoustic simulation program to overcome the limitations of a very simplified model, this paper has researched and proved the feasibility in the case of the rectangular sound source. Through the continuous development of the algorithm, the accuracy and reliability of the simulation program can be improved. This paper has also presented the clue of the prediction model which can get results as accurate as the measurement value.