The present investigation concerns the development of advanced scalar turbulence modeling approaches and their application to the calculation of non-isothermal wall-bounded flow phenomena. A new scalar modeling technique based on scalar turbulent scales is proposed and implemented at a second-order modeling approach. Instead of the classical analogy concept between the mechanical and the scalar...

We investigate numerically the transition to turbulence in a flat-plate boundary layer controlled by electromagnetic forces. The fluid considered is incompressible, Newtonian and low electrically conductive. Similar to boundary layer suction, when applying a steady, wall-parallel, and streamwise oriented Lorentz force, the Blasius velocity profile is transformed to an exponential one. Since the...

The paper suggests a stationary model of the vertical distribution of the concentration of suspended sediment in the bottom layer of a natural water body with a flat bottom. The model explains the concentration distribution, formed jointly by the settling of suspended particles and turbulent diffusion. The flow is assumed geostrophic above the bottom-influenced layer, while in the bottom layer ...

For some cases of diferrent boundary layer development conditions (roughness surface, turbulence in main flow) by adverse pressure gradient was determined tranzitiom region. Boundary Tranzition region found based on intermittency flow inside the layer. Intermitency evaluated using modiffied TERA method algorithm.

Data from SABLES98 experimental campaign have been used in order to study the influence of stability (from weak to strong stratification) on the flux-profile relationships for momentum and heat: φm and φh. Standard instrumentation, 14 thermocouples and 3 sonic anemometers at three levels (5.8, 13.5 and 32 m) were available from 10 to 28 September 1998 and calculations are done in order to extra...

The scientific objectives are to: 1) document the structure and characteristics of entrainment circulations in marine stratocumulus and fair-weather-cumuli, 2) characterize the vertical distribution of drizzle and how it relates to cloud and mesoscale circulations; 3) investigate the relative role of cloud thickness, cloud turbulence intensity, and aerosols on drizzle production; 4) study the p...

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...

The shape of the air flow in the interior is heavily influenced by the air distribution system and the way air enters and exits. By numerically simulating flow by computational fluid dynamics, one can determine the flow pattern and temperature distribution and, with the help of the results, provide an optimal design of the air conditioning system. In this study, a chamber was first constructed ...

The Ekman boundary layer (EBL) is a non-stratifi ed turbulent layer of fl uid in a rotated frame of reference. The EBL comprises two sub-layers, namely, the surface sub-layer, where small scale well-developed turbulence dominates, and the core sub-layer, where large scale self-organized turbulence dominates. This study reports self-organization of large scale turbulence in the EBL as simulated ...

This paper is concerned with the transition to turbulence in flat plate boundary layers due to moderately high levels of free-stream turbulence. The turbulence is assumed to be generated by an (idealized) grid and matched asymptotic expansions are used to analyse the resulting flow over a finite thickness flat plate located in the downstream region. The characteristic Reynolds number Rλ based o...