Table I.

Relative errors in the effective velocity in percent defined as $100|v_{\mathit{eff}}^{sim}-v_{\mathit{eff}}^{theory}|/v_{\mathit{eff}}^{sim}$, where $v_{\mathit{eff}}^{sim}$ and $v_{\mathit{eff}}^{theory}$ are the effective velocities obtained from the simulations and given by Eq. (5.9), respectively.

b	0.05				0.1
${\overline{v}}_{\mathit{f}}$	5	10	15	20	5	10	15	20
a = l = R = 1	0.81	0.95	0.85	0.92	1.28	1.31	1.32	1.26
l = R = 1, a = 2	0.95	0.89	0.83	0.89	0.72	1.23	1.16	1.41
a = R = 1, l = 2	0.87	0.97	0.95	0.82	1.24	1.29	1.17	1.11
a = l = 1, R = 2	0.77	0.88	0.86	0.81	1.45	1.55	1.18	1.43