Simulation-Based Design Strategy and Experimental Validation of an Active Noise Control Setup

During the pandemic, mobile ventilation systems became increasingly popular. These systems filter the air in a room by moving it through a filtration system. This process generates noise, primarily at the air inlet and outlet of the unit. To meet regulatory requirements and design goals this noise must be minimized. Active Noise Control (ANC) is an effective way to influence airborne sound paths. To mitigate broadband stochastic noise, reference microphones within the ventilation system detect the noise in advance. By using an array of multiple loudspeakers, the propagation of noise into the free field can be controlled. Such an ANC system can also reduce noise in many other applications, such as heat pumps, industrial ventilation, and residential air conditioning. Setting up an acoustic simulation model and a virtual test bench can significantly increase design efficiency. This improves the quality of the solution in advance without relying on a physical prototype. Such a setup allows for efficient numerical investigations on appropriate positioning of ANC components, how to parameterize the controller, and what to expect in the real world. Free-field simulations are performed using the finite element (FE) method and transferred to a time-domain system simulation to evaluate component placement and controller design.