Experimental Investigation of the Time Effect of Pressure Fluctuations in Steady Turbulent Pipe Flows

Abstract

Inthe study, which performed experimentally, the behavior of time variation ofthe static pressure in pipe water flows has been investigated in terms of pipediameter, flow rate and pipe roughness. In the experiments, five pipe types indifferent materials and in different roughness were used. In the steady andhorizontal pipe water flows, which performed at low Reynolds numbers, thestatic pressure at different tap locations which is longitudinally placed havebeen measured. The water heights in the piezometer hoses, which is inserted onpressure taps, has been recorded with a camera for three minutes for each flowrates. A total of 21 snapshots were obtained from each camera recordings atequal time intervals and the pressures were determined from that snapshotimages through water height readings. The sanpshots of any flow rate has shownthat all pressures at the tap locations fluctuate together over the time in thesame phase, frequency and amplitude. When RMS values, which shows the pressurefluctuation in mean intensity over the time, was examined, it was observed thatthe fluctuation amplitudes is independent of pipe roughness but has a relationwith velocity of the pipe flow.