Spectral shortcut in turbulence energy transfer in open channel flow over submerged vegetation

Hydrodynamic pressure and effective mixing length in vegetated free-flow region

“…This phenomenon reflects the vertical variation in shear turbulence intensity. Since the upward development of the free shear turbulence is independent of submergence in H/ h v ≥ 5 conditions [10], the L/ (h o -h v ) profiles in the lower zone coincide with each other in Cases B-5-30, B-6-30, and B-7-30.…”

“…Therefore, (1) the inflection point locates at middle position of the PML, but it lies at canopy top (z = h v ) in the VSL [1]; and (2) an anti-symmetric U profile is observed in the PML rather than in the VSL [12]. Zhao et al [10] divides the VSL into the free-flow region and the canopy region (Figure 1), and the thickness of the former one (i.e., h o -h v ) is significantly larger than thickness of the latter (i.e., h v -h p ). On the base of the VSL subdivision, the U distribution law for each region has been separately proposed through turbulence theory analyses [12].…”

“…(grey items in the figure represent the simplified vegetation) [1,10]. In fact, hydrodynamics in the vegetated shear layer (VSL) is not absolutely same as in the traditional plane mixing layer (PML) [11].…”

“…Each case is labeled as "letter -H/ h v -U m ", where letters A, B, C, D, E, and F represent different S x and S y conditions. For specific information about the experiments, please refer to [10][11][12].…”

“…It is observed that L/ (h o -h v ) decreases with λ and H/ h v but shows little variation with U m . This can be explained by the following reasons: (1) the former two factors control turbulent motion by affecting flow discontinuity at the canopy top and the turbulence upwards development, respectively [1]; (2) an increase in U m would intensify turbulence but does not fundamentally alter turbulent motion [10].…”