4.1 Flow Rate Measurement in 2-in diameter Stainless Steel pipe
During the experiments, a homogeneous bentonite-water mixture was pumped through a 2-in pipe. Variable frequency drive (VFD) was installed to regulate the pump speed. This was to minimize the disturbance resulting from throttling the valve to improve the flow meter accuracy. Figure 3 shows typical experimental readings acquired from transit-time ultrasonic flow meter and its comparison to the rate of the flow as collected in the volume tank. Each experiment was conducted at unsteady flowing condition with flow accelerating from rest to 1.2 ~1.5 m/s, and next, decelerated to rest again, within a duration of 20~25 seconds.