Sheared stably stratified turbulence and large-scale waves in a lid driven cavity
arXiv:1405.5933 · doi:10.1063/1.4898192
Abstract
We investigated experimentally stably stratified turbulent flows in a lid driven cavity with a non-zero vertical mean temperature gradient in order to identify the parameters governing the mean and turbulent flows and to understand their effects on the momentum and heat transfer. We found that the mean velocity patterns (e.g., the form and the sizes of the large-scale circulations) depend strongly on the degree of the temperature stratification. In the case of strong stable stratification, the strong turbulence region is located in the vicinity of the main large-scale circulation. We detected the large-scale nonlinear oscillations in the case of strong stable stratification which can be interpreted as nonlinear internal gravity waves. The ratio of the main energy-containing frequencies of these waves in velocity and temperature fields in the nonlinear stage is about 2. The amplitude of the waves increases in the region of weak turbulence (near the bottom wall of the cavity), whereby the vertical mean temperature gradient increases.
11 pages, 14 figures, REVTEX4-1
References in corpus (13)
- Energy- and flux-budget (EFB) turbulence closure model for the stably stratified flows. Part I: Steady-state, homogeneous regimes
- Turbulence energetics in stably stratified geophysical flows: strong and weak mixing regimes
- A hierarchy of energy- and flux-budget (EFB) turbulence closure models for stably stratified geophysical flows
- Experimental observation of the steady - oscillatory transition in a cubic lid-driven cavity
- Energy- and flux-budget turbulence closure model for stably stratified flows. Part II: the role of internal gravity waves
- Generation of Large-Scale Vorticity in a Homogeneous Turbulence with a Mean Velocity Shear
- Large-scale instability in a sheared nonhelical turbulence: formation of vortical structures
- Tangling clustering of inertial particles in stably stratified turbulence
- Turbulent thermal diffusion in a multi-fan turbulence generator with the imposed mean temperature gradient
- Turbulent thermal diffusion of aerosols in geophysics and laboratory experiments
- Hysteresis phenomenon in turbulent convection
- Transition phenomena in unstably stratified turbulent flows
- Experimental study of temperature fluctuations in forced stably stratified turbulent flows