Figure 5
Panels (a): Effective \(\mathrm{Nu^*=Nu^*(Ra^*)}\) scaling for highly turbulent strongly modulated convection (top) and the same data series (as indicated and described in more detail in the text) shown in the compensated form (bottom). The symbol denoted 2mod corresponds to the case of simultaneous modulation at two frequencies, as shown in Fig. 6. Panel (b): Prefactor \(\xi _0({\text{Ra}})\) in equation (5) calculated for the particular case of power law scaling exponent \(\gamma =1/3\), observed experimentally28,29 in the range of Ra of interest for unmodulated, steady-state RBC. Panels (c): Ratio of measured to calculated values of \(\langle Q_{{\text{B}}}(t) \rangle /\langle Q_\mathrm{{B0}}\rangle\) and \(\langle \Delta T^* \rangle /\langle \Delta T_0^*\rangle\) for various \(A_{{\text{T}}}\) and \(f_{{\text{T}}}\) plotted versus the controlling parameter \(\langle \Delta T(t)\rangle /A_{{\text{T}}}\) (left) and versus \(f_{{\text{T}}}\). The color-coded data series correspond to parameters as indicated; the crosses represent the data obtained in our recent study17, displaying the same decreasing tendency with increasing \(\langle \Delta T(t)\rangle /A_{{\text{T}}}\).
