附件242 国Chopter2 damentl yrnie Fid e◆a 3 Viscosity The sketeh of viscosity is illustrated by Fig 2-1 Cohesion between two mnolecules. have u+du reen the twe fhud t= Where lt is viscosity coefficient,also dynamic Fig.2-1 The sketch of viscosity 国Chopter2 Fandamental历draieFid Mechanie年a There are three methods to describe the viscosity: absolute viscosity,Kinematic viscosity and relative viscosity. (1)Dynamie viscosity or absolute viscosity (Pa.s)or(Nm (2)Kinematic viscosity (mm2/s) =u (2-4) (3)Relative viscosity (conditional viscosity) The relative viscosity E which used in China is tested by the E iscometer,such as Fig.2-2. 9附件 24.2 9