Optimisation with genetic algorithm of the acoustic performance of T-shaped noise barriers with a reactive top surface

Performance of Traffic Noise Barriers with Varying Cross-Section

“…If we assume that the sound pressure in each point of space depends harmonically on time, then the sound pressure is given by (5), where x, y and z are Cartesian coordinates of the imission point. In order to obtain the sound pressure value in that point, a solution to the homogenous Helmholtz equation given by (6) has to be found, where / k c 2 r m = = is the wave number (rad/m), c is the speed of sound (m/s), m is the wavelength (m). If there is a source in position ( , , x y z 0 0 0 ), the sound field can be described by a homogenous Helmholtz equation (7), where , , x x y y z z …”

“…The Y-and T-shaped elements have proven to work very well for sound diffusion. The T shape was further studied by Baulac et al [6], as well as Monazam and Lam [7], and a contribution to the optimization of Y shaped barriers was given by Grainer et al [8]. Ishizuka and Fujiware [9] compared the efficiency of a number of different types of diffusers placed on top of the barriers.…”

Research of Different Noise Barriers Efficiency at Different Temperature

“…Making the geometric noise barrier changes take into account the height of the wall and construction costs . According to the studies carried out and developed methods have been established as the noise barrier design changes at the peak of the barrier leads to a higher noise reduction (Baulac et al 2008;Greiner et al 2010). To improve the acoustic performance of noise barrier, construction is designed in various forms: T, Y, round, cylinder etc.…”

Fuzzy TOPSIS Approach in Selection of Optimal Noise Barrier for Traffic Noise Abatement

“…The capped barriers have specially shaped top sections that reduce the sound power contribution from acoustic waves diffracted over the top (Watts, 2002). The notable developments include parallel noise barriers (Watts, 1996), inclined barriers (Cheng, Ng, 2001), barriers with absorbent/soft/reactive surfaces (Fahy et al, 1995;Monazzam et al, 2010;2011), diffusive noise barriers (Cianfrini et al, 2007), wedge shaped noise barriers (Ouis et al, 2003), multiple-edge noise barriers (Crombie et al, 1995), T-shaped noise barriers (Baulac et al, 2008), and other novel barrier profiles (May et al, 1980) etc. The above studies generally include experimental, theoretical, and numerical analyses with an objective of predicting the barrier insertion loss in laboratory and free field conditions.…”