Distribution of injected power fluctuations in electroconvection

Abstract

We report on the distribution spectra of the fluctations in the amount of power injected into a liquid crystal undergoing electroconvective flow. The probability distribution functions (PDFs) of the fluctuations as well as the magnitude of the fluctuations have been determined in a wide range of imposed stress both for `unconfined' and `confined' flow geometries. These spectra are compared to those found in other systems held far from equilibrium, and find that in certain conditions we obtain the ''universal'' PDF form reported in [Phys. Rev. Lett. {\bf 84}, 3744 (2000)]. Moreover, the PDF approaches this universal form via an interesting mechanism whereby the distribution's negative tail evolves towards form in a different manner than the positive tail.

13 pages, 3 figures