Assignment:
A capillary rheometer is used to measure viscosity. A pressure transducer records the pressure drop deltaP across the die, and the die capillary has a diameter of 2 mm. Experiments are carried out at three volume flow rates Q, for dies of three lengths l. The Table below gives values of deltaP in MPa measured for polypropylene at 190°C. Assuming Newtonian viscosity, find the apparent viscosity for each flow rate Q.
Q=2*10-7 m3/s Q=4*10-7 m3/s Q=8*10-7 m3/s
L=5 mm 1.502 2.100 2.935
L=10 mm 2.337 3.266 4.565
L=20 mm 4.006 5.599 7.826