Preliminary Measurements From A New Flat Plate Facility For Aerodynamic Research

This paper details the design and preliminary measurements used in the characterisation of a new flat plate research facility. The facility is designed specifically to aid in the understanding of entropy generation throughout the boundary layer with special attention given to non-equilibrium flows. Hot-wire measurements were obtained downstream of two turbulence generating grids. The turbulence intensity, integral and dissipation length scale ranges measured are 1.6%-7%, 5mm-17mm and 0.7mm-7mm, respectively. These values compared well to existing correlations. The flow downstream of both grids was found to be homogenous and isotropic. Flow visualisation is employed to determine aerodynamic parameters such as flow 2-dimensionality and the effect of the flap angle on preventing separation at the leading edge. The flow was found to be 2-dimensional over all measurement planes. The non-dimensional pressure distribution of a modern turbine blade suction surface is simulated on the flat plate through the use of a variable upper wall. The Reynolds number range based on wetted plate length and inlet velocity is 70,000-4,000,000

Visual Simulation of Experimental Oil-Flow Visualization by Spot Noise Images from Numerical Flow Simulation

. Comparative visualization of data from different sources provides useful presentations to highlight similarities or differences. Such methods are valuable for comparing results from numerical flow simulation with images taken during windtunnel experiments. The experimental flow visualization technique represents the surface flow field with oil streaks. We visualized the numerical surface flow field using the spot noise technique. The flow data are pre-processed and the parameters of the spot noise texture are tuned to enhance similarity of the resulting images. The result is a `visual simulation', based mainly on the choice of the quantities to be visualized and the mapping of these quantities to the spot noise parameters. Analysis of the relation between the pre-processing steps and the visualization parameters allows conclusions about the important mechanisms in the experimental flow visualization technique. Besides the comparison of numerical data and the windtunnel ex..

Scientific visualization of stress tensor information with applications to stress determination by X-ray and neutron diffraction

Includes bibliographical references (leaves 232-249).The visual analysis of mechanical stress facilitates physical understanding of the tensor quantity which is concealed in scalar and vector methods. In this study, the principles and techniques of scientific visualization are used to develop a visual analysis of mechanical stresses. Scientific visualization is not only applied to the final tensorial quantity obtained from the diffraction measurements, but the visual methods are developed from, and integrated into current residual stress analysis practices by relating the newly developed visual techniques to the conventional techniques, highlighting its advantages. This study consists of the mathematical analysis of the tensor character of mechanical stresses, discussion of the principles and techniques of scientific visualization (visual data analysis) in physical research, and tensor determination, visual analysis and presentation of residual stresses obtained from diffraction measurements

Localized flow, particle tracing, and topological separation analysis for flow visualization

Since the very beginning of the development of computers they have been used to accelerate the knowledge gain in science and research. Today they are a core part of most research facilities. Especially in natural and technical sciences they are used to simulate processes that would be hard to observe in real world experiments. Together with measurements from such experiments, simulations produce huge amounts of data that have to be analyzed by researchers to gain new insights and develop their field of science