A Simple Turbulent Kinetic Energy Equation and Aircraft Boundary Layer Turbulence
نویسنده
چکیده
The basic science of turbulence has been known for many years, yet the knowledge has hardly become a part of operational aviation turbulence forecasting. The history of turbulence forecasting, which has primarily concentrated at elevations above the boundary layer, has been an amalgamation of empirical rules of thumb and forecaster intuition, not of strong theory and conceptual models. Turbulence sources are examined from the turbulent kinetic energy equation. Data from a year-long study at the NOAA / National Weather Service / Aviation Weather Center shows that even a simple first order closure scheme has significant diagnostic skill in the boundq,ry layer for aviation pUlposes.
منابع مشابه
Numerical Simulation of Separation Bubble on Elliptic Cylinders Using Three-equation k-? Turbulence Model
Occurrence of laminar separation bubbles on solid walls of an elliptic cylinder has been simulated using a recently developed transitional model for boundary layer flows. Computational method is based on the solution of the Reynolds averaged Navier-Stokes (RANS) equations and the eddy-viscosity concept. Transitional model tries to simulate streamwise fluctuations, induced by freestream turbulen...
متن کاملEffects of coupling on turbulent gas-particle boundary layer flows at borderline volume fractions using kinetic theory
This study is concerned with the prediction of particles’ velocity in a dilute turbulent gas-solidboundary layer flow using a fully Eulerian two-fluid model. The closures required for equationsdescribing the particulate phase are derived from the kinetic theory of granular flows. Gas phaseturbulence is modeled by one-equation model and solid phase turbulence by MLH theory. Resultsof one-way and...
متن کاملLarge-eddy simulation of turbulent flow over an array of wall-mounted cubes submerged in an emulated atmospheric boundary-layer
Turbulent flow over an array of wall-mounted cubic obstacles has been numerically investigated using large-eddy simulation. The simulations have been performed using high-performance computations with local cluster systems. The array of cubes are fully submerged in a simulated deep rough-wall atmospheric boundary-layer with high turbulence intensity characteristics of environmental turbulent fl...
متن کاملObservations of Turbulence in the Ocean Surface Boundary Layer: Energetics and Transport
Observations of turbulent kinetic energy (TKE) dynamics in the ocean surface boundary layer are presented here and compared with results from previous observational, numerical, and analytic studies. As in previous studies, the dissipation rate of TKE is found to be higher in the wavy ocean surface boundary layer than it would be in a flow past a rigid boundary with similar stress and buoyancy f...
متن کاملDynamic response of boundary-layer turbulence to oscillatory shear
The temporal response of a well-developed turbulent boundary layer to the superposition of oscillatory shear has been measured experimentally, over a wide range of frequencies. The response is primarily a periodic organization in magnitude of components of the turbulent velocity field at the forcing frequency. Oscillatory production of turbulence arises predominantly as a modulation of the mean...
متن کامل