고분자용액에 의한 유체수송관벽의 저항감소 -II. 난류흐름에서 국소저항감소-

Drag Reduction of Pipe Wall For Fluid Flow due to Injected Polymer Solution - II. Local Drag Reduction in Turbulent Flow-

Dilute polymer solutions were injected into turbulent pipe flow of a Newtonian fluid. The local drag reduction for injection of polymer solution at the pipe wall was larger than that at centerline. From the above result we may conclude that the polymer additives were found to influence the flow in the neighborhood of the wall. The effects of the injection apparatus on the local drag reduction are small compared to the drag-reducing effects. The extent of drag reduction increased with polymer concentration and injection flow rate, and the maximum drag reduction obtained were 47% for Polyox Coagulant and 35% for Separan AP-273. In respect to polymer degradation, the polyacrylamide showed better shear stability than the polyethyleneoxide and thus the former expected to have a sharper molecular weight distribution.