Wall shearing stress is decreased by the existence of microbubbles in a turbulent boundary layer as discovered by McCormick and Bhattacharyya [1] in 1973.Since that time experimnetal research has been conducted on air-water bubble flow [2]-[7].It has been demonstrated that shearing stress is decreased to a value one order of magnitude lower than the original value under lptimum conditions [2].
展开▼