,54,20102 CHARACTERISTICS OF COHERENT STRUCTURE IN COMPOUND OPEN CHANNEL FLOWS WITH DEEP FLOOD PLAIN DEPTH 1 2 3 Katsutoshi WATANABE, Yousuke TOKUMITSU, Haruka YOSHINAGA 1 745-8585 3538 2 3 733-0812 13-7-502 In this study, characteristics of coherent structure in one-sided compound open channel flows with deep flood plain depth are investigated using PTV (Particle Trucking Velocimetry) and fluorescent dye injection method. The velocity measurement results show that the relative high speed region is formed over the flood plain and large negative and positive value of Reynolds stress (- ) are generated in the vicinity of junction edge. The results of flow visualization indicate that large-scale streamwise vortices are formed over the junction edge and side wall surface for a long time period. The streamwise vortices formed over junction edge tend to develop toward water surface intermittently, and decreasing tendency of their mean inclination angle in the opposite side wall is observed. Furthermore, it is inferred that interaction between streamwise vortices formed over the junction edge and the one formed over the side wall play important role in generating characteristic velocity profiles. Key Words: compound open channel flow, coherent structure, streamwise vortex, secondary current, flow visualization techniques H D H/D1.5 H/D H/D LDVPIVH/D1.5 H/D <1.5 H/D>1.5 H/D=1.5 H/D<1.5 H/D=2 H/D Naot H/D=2
risevor tank H/D=1.25 H/D z x 1/1000 6015,1m 15cm,4cm8m. 4mm 3.2cm25cm. 5m PTVParticle Tracking Velocimetry 100m4 1KW 3mm 800 1000 honeycom Flow Flood plain PTV 15 60 pit pump unit(cm) Case (a) (b) y/h y/h H (cm ) B f (cm) Flow H SONY HDR-FX1000 PTV PTV 14401080 Flow PTV 601800 PTV 05 200cc 55cm DPTV (Dye-streak-pattern Particle Velocimetry) 1cm B D D (cm) H/D Um (cm/s) y H fp B f z Re (Um*H/v) Fr (Um/ gh) A 12 3 10.2 8887 94 B 12 3 5.7 6819 53 C 12 15 4 3 3.3 6211 3 D 8 2 5.7 5202 64 E 8 2 4.7 4390 53 z/h z/h
0 0 0 - -0 - -0 U/Umax= 0.95 0.90 0.80 0.70 0.60 0 0.30 - -5 0 5 0.10 0.15 0.20 2.00 1.75 1.50 1.25 0 0 0 - -0 - -0-0 0 0 - -0 - -0 - - U/Umax= 0.90 - - -2.0-5 - - -2.5-5 0 0 0 - -0 - -0 - H=8cmCase D 0.80 0.70 0.60 0 0 5 0.10 0.15 0.20 2.00 1.75 1.50 1.25 0 0 0 - -0 - -0-0.95 0.90 0.85 0.80 0.70 0.65 0.60 0 0.20 U/Umax= 0.90 H=12cmCase A - - 0 5 0.10 0.15 0.20 -uw/u max 2 (Umax =7.41cm/s) 2.00 1.75 1.50 1.25 0 0 0 - - -0 - -0 - -5-5 - - - - -5 =4Umax Umax=7.41cm/s 0 5 0.10 0.15 0.20 0.80 0.70 0.60 0 = 5Umax Umax=13.64cm/s 0 5 0.10 0.15 0.20 1.5 2.0 - - - - - - -uw/u max 2 (Umax =13.64cm/s) 0 5 0.10 0.15 0.20 H=8cmCase D H=12cmCase A H/D,H=8cmH8H=12cm H12 H8U V,W H12H8 U/U max 0.8 H=8cmCase E Flood plain :Water surface 5 0.10 0.15 0.20 :Wall surface H=12cmCase B H8
H=8cm Case E H=12cm Case B H12 H8 H12 H8 H8H12
TH 1mm H8 y=cm streak streak H12 H8 streak H8 H8 H12 H8 H8y=3.9cm H12y=7.9cm L z H83.7cm L z /B f =H1211.4cmL z /B f =0.76 H/D H121/3 1/6150 H8-39 42H12H81/2-19 29H12,H8 H/D
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