Observation of temperature peaks due to strong viscous heating in a dusty plasma flow

Abstract

Profound temperature peaks are observed in regions of high velocity shear in a 2D dusty plasma experiment with laser-driven flow. These are attributed to viscous heating, which occurs due to collisional scattering in a shear flow. Using measurements of viscosity, thermal conductivity, and spatial profiles of flow velocity and temperature, we determine three dimensionless numbers: Brinkman, Br=0.5; Prandtl, Pr=0.09; and Eckert, Ec=5.7. The large value of Br indicates significant viscous heating that is consistent with the observed temperature peaks. © 2012 American Physical Society.