METHOD AND APPARATUS FOR REDUCING DISSIPATION RATE OF FLUID EJECTED INTO BOUNDARY LAYERS

摘要

Skin friction on a surface moving relative to a fluid can be obtained by ejecting a polymer-water mixture/solution (9) into the boundary layer. The efficacy of the ejected polymer-water mixture/solution is closely related to polymer dissipation out of the boundary layer and conditioning (i.e., lengthening, unwinding or stretching) of the polymer molecules by liquid shear force immediately before ejection. The invention is a method and apparatus for conditioning and ejecting a polymer-water mixture/solution (9) that improves drag reduction characteristics of the mixture/solution and maintains the mixture/solution in the boundary layer for as long as possible. By improving the drag-reduction characteristics of the polymer-water mixture/solution and by extending the time it remains in the near-wall region, the ejector can increase the performance and reduce the volume and stroge requirements of a drag-reduction system. Although this was intended for polymer-water mixture/solution ejection, it can be ejection of any substance into a flowing.