Previous work demonstrated that a multi-objective evolutionary algorithm could be successfully employed as an optimiser to make the design of flat-walled multi-layered anechoic linings more efficient. In the present work, such an algorithm is employed to investigate the practical aspects of the application of multi-layered polyurethane foams as the flat-walled anechoic lining. The investigation includes aspects such as the efficacy of a single layer of material, the minimum number of layers of linings to achieve the minimum overall thickness for low (100Hz), mid (250Hz) and high (500Hz) cut-off frequencies, the use of the three-layered lining composite for low to mid cut-off frequencies and the effect of air gaps.
Applied Acoustics, 2006, Vol 67, Issue 5, p. 476-485
anechoic chamber; anechoic lining; building acoustics