Affiliations: Institute of Fluid Dynamics, ETH Zürich,
Sonneggstr. 3, CH-8092 Zürich, Switzerland. E-mail:
[email protected] | Institute of Fluid Dynamics, ETH
Zürich
Abstract: The development of a measurement system for the visualization,
topological classification and quantitative analysis of complex flows in
large-scale wind tunnel experiments is described. A new approach is sought
whereby the topological features of the flow, e.g. stream lines, separation and
reattachment regions, stagnation points and vortex lines are extracted directly
and are preferably visualized in real-time in a virtual wind tunnel
environment. The system is based on a stereo arrangement of two CCD cameras. A
frame rate of 120 f/s allows measurements at high flow velocities. Helium
filled soap bubbles are used as tracer particles. The present paper describes a
simple camera calibration procedure for large measurement environments and
examines the problem of fast and accurate reconstruction of path lines in three
dimensions, which will enable true three-dimensional and time-resolved fluid
flow visualization. Experimentally obtained visualization results for a
free-stream flow, flow around a circular plate and flow over a delta wing are
presented.