Kinematic wall friction properties of reed canary grass powder at high and low normal stresses

The effects of varying reed canary grass (RCG) powder moisture contents on the relationship between its coefficient of kinematic wall friction and normal stress were modelled, using experimental designs and multivariate analysis, at a range of both low (520 to 7520 Pa) and high (23 to 275 MPa) normal stresses. The coefficient of kinematic wall friction at low normal stresses (µL) correlated positively with moisture content and negatively with normal stress. Also, at high normal stresses, µH was negatively correlated to normal stress. A µH maximum was found at moisture contents of 13–15% and at the lowest normal stresses in the measurement range. The moisture content interval for the µH and RCG pellet durability maxima overlapped, suggesting that µH and RCG pellet durability are correlated.