Dresden 2009 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 24: Pattern formation in colloidal and granular systems I
DY 24.4: Vortrag
Donnerstag, 26. März 2009, 15:30–15:45, ZEU 255
Humidity determines granular transport hysteresis — •Tobias Lang1, Christof Krülle1,2, and Ingo Rehberg1 — 1Universtität Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth — 2Maschinenbau und Mechatronik, Hochschule Karlsruhe - Technik und Wirtschaft, D-76133 Karlsruhe
Since the pioneering works of R.A Bagnold, a grown interest in dune dynamics evolved. Incipient motion of a sand bed starts, when the wind speed over the bed surpasses a critical threshold. It is known that the sand flux depends sensitively on the humidity of the air. Using a small scale closed-circuit wind tunnel with active moisture control, we studied the dependency of the granular transport process on the humidity. Via the variation of humidity, electrostatic charging of the particles can also be influenced. In particular we measure the hysteretic dependence of the sand flux on the wind speed.