Vrije Universiteit Brussel
The ESPRIT project ALICE focuses on the development of a Quantitative Flow Field Visualization (QFView) system. QFView is a graphically distributed software environment that integrates EFD and CFD data processing (e.g. flow field mappings with flow field visualization). The QFView system supports a unified treatment of data while : -validating results produced from experimental and numerical systems, and - archiving and retrieving data from the unified flow field database. The fluid dynamics data generated with Experimental Fluid Dynamics (EFD) and Computational Fluid Dynamics (CFD) simulations require fast and easy access in order to be of interest in industrial environments. The aim is to combine results from different simulations (PIV, CFD, LDV...) : (i) to improve the physical understanding of the flow phenomena, (ii) to validate and improve CFD codes, (iii) to use EFD techniques efficiently and (iv) to provide user friendly access to all this information. To prove the versatility of such approach several experiments are chosen from various application fields. Their requirements steered the design of the QFView system (final output of the EP-28168 ALICE project). At VUB, a facility for Particle Image Velocimetry (PIV) is constructed using the continuous-wave 4W Argon Ion Laser.The pulses necessary for PIV are generated with a Bragg cell, which is driven by a generator. The TTL signal coming from a synchronizer triggers the RF generator. The laser sheet is produce by cylindrical lens from the frame-straddled pulses. The digital camera captures the images of the illuminated particles.A spatial Cross Correlation Algorithm quantifies the instantaneous velocity field from the acquired images. A specially designed mini-water tunnel is constructed to investigate the complex flow field of a double annular jet. Recently purchased 30mJ Nd-YAG pulse laser (allows air velocity measurement up to 45m/s), will be integrated in our PIV system. The distributed nature of QFView allows the user to extract, visualize and compare data from the database over the Word Wide Web, Emphasis is given to the treatment of non-stationary and transient data, which requires animation and time dependent visualization tools. The visualization of the velocity field, the mean velocity and turbulence quantities from, PIV, LDV and CFD are demonstrated. the QFView architecture is characterised by three important requirements: to be open, web-based and componentised.It is modularized in order to improve flexibility and integration of (current and future) visualization components. In addition to standard set of visualization components representing scalar and vector fields, a special weight is given to comparison and extraction procedures, which ease and improve interactive manipulation of large data sets (search, browsing...). the central point is the database where large amounts of data sets are imported, classified and stored for further reuse. We believe that WWW represents the future of distributed, collaborative scientific environments. Thus, QFView is based on web-oriented client- server technology (e.g. Java, JDBC). It is envisaged that QFView will reduce the global costs and time required: to process, to validate and classify results addressing fluid mechanics problems.