UTILIZING SCHLIEREN IMAGING TO VISUALIZE HEAT TRANSFER STUDIES

摘要

Convective heat transfer beyond explicit solutions to the Navier Stokes equations is often an empirical science. Schlieren imaging is one of the only fluid imaging systems that can directly visualize the density gradients of a fluid using collimated light and refractive properties. The ability to visualize fluid densities is useful in both research and educational fields. A Schlieren imaging device has been constructed by undergraduate students at the University of Portland. The device is used for professorial heat transfer and fluid dynamics research and to help undergraduates visualize and understand natural convection. This paper documents the design decisions, design process, and the final specifications of the Schlieren system. A simple 2-D heated cylindrical model is considered and evaluated using Schlieren imaging, OpenFOAM C.F.D. simulation, and convection analysis using a Nusselt correlation. Results are presented for the three analysis techniques and show excellent verifications between the CFD simulation, Nusselt correlation, and Schlieren imaging system.