Abstract: “The characteristics of velocity fields of the external and boundary layer flo ws during run - up motion of a non - breaking solitary wave propagating over a 1:3 sloping beach are explored experiment ally. Flow visualization technique (FVT) of particle trajectory photography and high - speed particle image velocimetry (HSPIV) were employed to qualitatively observe and quantitatively measure the macro - viewed external and micro - viewed boundary layer flow fields . The experiments were conducted in wave flume equipped with a wave maker being triggered by a precise servo - motor . The incident wave - h eight to water - depth ratio s , H 0 / h 0 , is equal to 0. 363 . The slope of the sloping beach model is fixed at 1 :3. Profoundly d istinct characteristics of flow fields around the flow demarcation curve s, as observed respectively from the macro - view ed external flow and the micro - viewed boundary layer flow , are first interpreted, together with eluci dation of the flow reversal ex”

Keywords: velocity field, flow visualization, high-speed particle image velocimetry, wall jet