Investigation on absorptive material placement in air cleaner

In order to improve the transmission loss in air cleaner, a method of properly placing absorptive material in cleaner was proposed. Applying finite element method, a simplified air cleaner was modeled as a cubic chamber with smaller sizes. The modal analysis results show that the modes maximum pressure regions of the acoustic modes concentrate at the corners and edges of the chamber. At these regions, the absorptive material was placed to improve the transmission loss. It can be seen that the transmission loss is improved greatly in mid and high frequency ranges and the result is better than that by the method of increasing the thickness of filtering paper. Applying the procedure to a real design of air cleaner testifies the procedure is reasonable and feasible. It can be applied in air cleaner design to increase the mid and high frequency components of transmission loss of air intake systems.