01596nas a2200157   4500008004100000245006200041210006200103260000800165300002300173490000700196520109300203100001301296700002101309700002101330856008701351       2007                        eng d00aLubrication effects on the flow of wet granular materials0 aLubrication effects on the flow of wet granular materials  cAPR  aArticle No. 0313020 v763 a<p>We investigate the dynamics of a partially saturated grain-liquid mixture with a rotating drum apparatus. The drum is partially filled with the mixture and then rotated about its horizontal axis. We focus on the continuous avalanching regime and measure the impact of the volume fraction and viscosity of the liquid on the dynamic surface angle. The inclination angle of the surface is observed to increase sharply to a peak and then decrease as a function of liquid volume fraction. The height of the peak is observed to increase with rotation rate. For higher liquid volume fractions, the inclination angle of the surface can decrease with viscosity before increasing. The viscosity where the minimum occurs decreases with the rotation rate of the drum. Limited measurements of the flow depth were made, and these were observed to show only fractional changes with volume fraction and rotation speeds. We show that the qualitative features of our observations can be understood by analyzing the effect of lubrication forces on the time scale over which particles come in contact.</p>1 aXu, Qing1 aOrpe, Ashish, V.1 aKudrolli, Arshad  uhttps://library.ncl.res.in/content/lubrication-effects-flow-wet-granular-materials