Regensburg 2007 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 24: Poster I
DY 24.62: Poster
Mittwoch, 28. März 2007, 16:00–18:00, Poster D
Temperature fluctuations in a heated free jet measured by a new microscopic temperature sensor — •Florian Heidemann, Marco Munzel, and Achim Kittel — University of Oldenburg, D-26111 Oldenburg
Turbulence is a phenomenon whose basic principles are still not well understood. One approach to investigate its nature is the charaterization of passiv scalars such as temperature. With a new developed fast thermosensor we are able to measure the temperature fluctuations in a heated free jet of water in a water tank with high spatial and temporal resolution at different positions and for different flow velocities. The used nozzle has a diameter of 2mm, which provides a laminar flow with a rectangular velocity profile at the outlet. The sensor is based on a miniaturized thermocouple and has an active area of approx. 0.05µ m2 and a response time of approx. 10µ s in water with a temperature resolution of 50mK (measured with a bandwidth of 100kHz). Our aim is to characterize the temperature fluctuations of the free jet with power spectra and increment distributions depending on the position perpendicular and parallel to the symmetry axis with respect to the nozzle.