Abstract

HERNANDEZ OLIVARES, A. O.  and  OCAMPO TORRES, F. J.. Sobre la disipación de energía cinética turbulenta asociada con olas que aún no rompen. Rev. mex. fis. [online]. 2022, vol.68, n.5, e50601.  Epub Feb 17, 2023. ISSN 0035-001X.  https://doi.org/10.31349/revmexfis.68.050601.

The turbulent kinetic energy dissipation is an essential quantity in the study of turbulence in fluids. In particular, on the transference of turbulent energy from large to small scales and determining its state of equilibrium and stationarity. This work has the purpose of understanding turbulence generation by non-breaking waves from turbulent kinetic energy dissipation analysis. Different groups of nonbreaking monochromatic waves with different slopes ξ (0.012 ≤ ξ ≤ 0:273), were mechanically constructed in a laboratory, whereby an acoustic device, the wave orbitals velocities were measured in various depths. Considering the inertial subrange in the power spectrum of components of turbulence velocity u ’ (t, z) and w ’ (t, z), a turbulent kinetic energy dissipation ε u ’(z) and ε w ’(z) was quantified, respectively. It was detected that the magnitude of both ε u ’(z) and ε w ’(z) increases with the wave slope ξ, and they are invariant to axis rotation (ε u ’(z)≈ε w ’(z)), especially for great values of z. It was distinguished that most of the profiles ε u ’(z)~ z n1 and ε w ’ (z)~ z n2 agree with an atypical logarithmic layer (n 1 , n 2 < -1) and that increasing ξ decreases (increase) exponent values n 1 (n 2). Finally, a term of the turbulence production ε wave was introduced, relative to nonbreaking wave orbitals velocities. Unlike other turbulence production terms or approximations, ε wave adequately reproduces the values of ε u ’(z) and ε w ’(z) regardless of ξ, which established that the wave orbitals velocities shear is the generator mechanism of turbulence in a fluid under nonbreaking waves.

Keywords : Nonbreaking waves; monochromatic waves; turbulent kinetic energy dissipation rate; turbulence production; logarithmic layer.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )