norm error is in the range 10-6 to 102. Within the range one can notice kh=0.01-0.1, that the use of and produces more accurate results in comparison to rinfl=2h rinfl=3h Some peak values are observed in the plots which are due to the resonant rinfl=4h. wavenumbers for the solution domain considered. If we disregard those resonance effects, the L2 norm error increases with value for all three methods. This is an kh expected behaviour due to the previously mentioned pollution effect. Figure LBIE-RBF-m=6 solution within the . Figure 4.15 presents the L2 norm errors for LBIE-RBF. Same range of values are kh used as in the previous case; though the magnitude of order of the obtained L2 norm error varies in the range 10-3 to 102 for this method. Within the range kh=0.01-0.1, performs better than the other two values. rinfl=3h rinfl Figure LBIE-RBF- solution within the range . In Figure 4.16, the results obtained with LBIE-RBF- are shown which are superior to the previous two methods. The L2 norms are as low as 10-10-10-8 in the range The explanation to this fact is quite straightforward. As shown in kh=0.01-0.1. Section 4.2.1, the frequency dependent basis functions prove to be ‘dispersion-free’ when the plane wave propagation angle, of the inserted basis coincides with the β,
norm error is in the range 10-6 to 102. Within the range kh=0.01-0.1, one can notice that the use of rinfl=2h and rinfl=3h produces more accurate results in comparison to rinfl=4h. Some peak values are observed in the plots which are due to the resonant wavenumbers for the solution domain considered. If we disregard those resonance effects, the L2 norm error increases with kh value for all three methods. This is an expected behaviour due to the previously mentioned pollution effect. Figure LBIE-RBF-m=6 solution within the . Figure 4.15 presents the L2 norm errors for LBIE-RBF. Same range of kh values are used as in the previous case; though the magnitude of order of the obtained L2 norm error varies in the range 10-3 to 102 for this method. Within the range kh=0.01-0.1, rinfl=3h performs better than the other two rinfl values. Figure LBIE-RBF- solution within the range . In Figure 4.16, the results obtained with LBIE-RBF- are shown which are superior to the previous two methods. The L2 norms are as low as 10-10-10-8 in the range kh=0.01-0.1. The explanation to this fact is quite straightforward. As shown in Section 4.2.1, the frequency dependent basis functions prove to be ‘dispersion-free’ when the plane wave propagation angle, β, of the inserted basis coincides with the