| Popis: |
Measurements of pressure drop and flow rate for dilute solutions of high molecular weight polymers flowing through a porous medium show an unusually high pressure drop. The excess pressure drop due to the presence of polymers was found to be very high with a marked non-Newtonian behaviour. The intrinsic viscosity of the polymers attained a value two orders of magnitude greater than that measured in pure shear flow. After an abrupt onset the intrinsic viscosity increased rapidly with increasing strain rate to a peak value, where-after it decreased. The increase in intrinsic viscosity correlates with a permanent lowering of the apparent molecular weight, i.e. a polymer degradation. |
