Hydrodynamic Forces On A Submarine Pipeline

The hydrodynamic forces acting on a submarine pipeline subjected to transverse horizontal currents have been, in some cases, completely overlooked or grossly underestimated. The paper describes the obtaining of experimental data and the interweaving of theoretical and experience for establishment of these forces. The forces of drag and lift were determined by measuring the differential pressure around the periphery of the pipe. This was accomplished by installing pressure-sensing stations in one transverse plane of the pipe and recording the differential pressures along with the properties of the flowing media. Velocity measurements were obtained by use of a pitot tube and a static pressure tube set in the stream flow. A glass tube was set on an incline and calibrated for direct visual velocity readout in inches of water and in feet per second. The pressure differential data velocity and flowing media properties were recorded by a Polaroid camera and transferred to worksheets used for determining the drag and lift for a 1-ft-long pipe increment. These differential forces were subdivided into 12 segments around the periphery of the pipe; resolved into their horizontal and vertical components, which were summed up into drag and lift forces.