Flow over a downstream-facing step is predicted using the F.E.M. A two-equation model of turbulence is employed where the transport of turbulence kinetic energy and dissipation rate are depicted using transport-type equations, i.e. the two-equation model of turbulence. The results obtained are compared with other models and experimental results. Generally, the model was found to be under-predic...

The parameterization of unresolved processes in oceanographic models is complicated by the interplay of processes on a wide variety of space and time scales. The lack of spectral gaps further complicates the situation, though perhaps not as seriously as might be feared. Understanding the interaction of different processes, and determining which one is critical, or rate-controlling, may be aided...

E-learning is popularized so fast and Collaborative Learning (CL) becomes so important an instructional strategy. There are huge Group Session (GS) texts needed to be analyzed to evaluate CL, thus the automatic or semi-automatic methods of analyzing the GS texts become very important. In this paper we present a method called Interaction Analysis depended on Knowledge Extraction (IAKE) to analyz...

The aim of our study is to analyze the impact of insertion holes in the middle of obstacles on the flow around a surface-mounted cube, In order to do this; we studied four configurations of obstacles in a channel with a Reynods number based on obstacle height ReH = 40000. The hexahedral structured meshes were used to solve the fluid dynamics equations .The finite volume method are employed to s...

To develop an accurate, compact and sensitive optical sensor capable of performing non-invasive instantaneous measurements of the rate of dissipation of turbulent kinetic energy TKE (E [m2/s3]). Turbulence dissipation rates provide vital information to determine mixing processes in the water column. In addition, enables the scaling information needed to link large mixing events with smallscale ...

[1] High-resolution measurements of near-bottom temperature stratification and current velocity were performed on the sloping boundary of a large lake at the depth of the seasonal thermocline. The measurements cover nearly the entire stratified period and reveal the periodic occurrence of strong temperature and current velocity fluctuations, which can be attributed to shoaling high-frequency in...

cylinder tumble flows of a single cylinder two-valve engine under motoring conditions with two pentroof pistons having different cavities at an engine speed of 1000 rev/min., during suction and compression strokes using particle image velocimetry (PIV). The two-dimensional velocity vector fields are analyzed on a vertical plane passing through the axis of the cylinder. To quantify the tumble fl...

A numerical model was used to simulate the bottom Ekman layer of a continental shelf region. The basis for the model was the Mellor and Yamada level 2« turbulence closure scheme. Conservation equations for momentum, turbulent kinetic energy, and turbulent length scale were utilized in the model. The model was used to simulate data taken from a Cyclesonde mooring on the Peruvian continental shel...

The specific objectives of this project are to obtain a critical evaluation of turbulence closure models that are commonly used in the coastal ocean, and to identify ways to improve these models. Of particular interest are the MY-2.5 model (Mellor and Yamada, 1974, 1982) and the k-e model (e.g., Rodi, 1987), which involve coupled equations describing turbulent kinetic energy and turbulent scale...

This contribution investigates the nature of turbulent kinetic energy (TKE) in a steep and narrow Alpine valley under fair-weather summertime conditions. The Riviera Valley in southern Switzerland has been chosen for a detailed case study, in which the evaluation of aircraft data (obtained from the MAP-Riviera field campaign) is combined with the application of high-resolution (350 m) large-edd...