RESEARCH ON THE SPECIFIC VISCOSITY OF SEMI-CONCENTRATED FIBER SUSPENSIONS

The viscosity properties of the semi-concentrated suspensions of fibers with small aspect ratio were investigated in transient shear flow using a concentric cylinder geometry. Experimental results were compared with predictions by utilizing the constructive model developed by Batchelor in conjunction with the hybrid closure proposed by Advani and Tucker. To rectify the discrepancy between the theoretical prediction available at the present time and the measured data, a new expression for the specific viscosity in the semi-concentrated shear flows of fiber suspension is proposed allowing for the effects of the fiber–fiber interactions and the finite-aspect-ratio fiber. The results show that the model predictions for the fiber suspensions of different aspect ratio and concentration are fairly good.