Fig. 6. Spectral power of the normalized dye concentration as a function of the frequency for AR = 1.1 and AR = 1.8. Plots (a) and (b) correspond to the time series shown in Fig. 5(a) and (b), respectively, and plots (c) and (d) correspond to the time series of Fig. 5(d) and (e), respectively. (a) Wi = 6.6, Re = 9.1 × 10–5; (b) Wi = 19.6, Re = 3.7 × 10–4; (c) Wi = 3.4, Re = 3.5 × 10–5; (d) Wi = 7.6, Re = 1.0 × 10–4.
