Development of active noise control simulation with virtual controller based on computational aeroacoustics

Noise reduction and control research are actively conducted as increasing noise problems compel the stringent noise requirement. Active noise control (ANC) is constructively used in various applications to reduce low-frequency noise. In previous studies, ANC systems were designed based on experiments, requiring extensive effort for effective implementation. In this paper, a real-time ANC simulation in a computational aeroacoustics framework based on the virtual-controller method is presented. The aims are to investigate sound field changes following ANC system operation and gain more insight into ANC system design through a computational approach. Using a virtual-controller ANC simulation, the approximate shape of the acoustic path filter and changes in the sound field when ANC is either "on" or "off" at the target domain can be obtained, enabling practical and detailed analyses. Then, the computational results of the duct and open space cases are predicted and compared with the experimental results to validate the prediction capability of the proposed method. In addition, the ANC system design parameters and their effects on sound fields with unintended phenomena can be predicted. Through case studies, the ability to design, optimize, and predict the performance of the ANC system using the computational method is also demonstrated.