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OPEN CHANNEL FLOW 19-27 <br /> 1.001 Equation 19.99 can be solved directly for the velocity. <br /> K= R�/3A [SI] i9.98(a) Equation 19.100 is valid for culverts of any shape. <br /> / <br /> n <br /> h'- l 1n9) R2/3A [U.S.] 19.98(b) <br /> V= H [SI] 19.100(a) <br /> hydraulic head available, H, is divided be- L 1+ke n <br /> rhe total the velocity head in the culvert,the entrance loss 2g + 8441/ <br /> 3 <br /> tn'�n <br /> ( (if considered), and the friction. <br /> 2 v 2n 2Lf <br /> H 2g + � (29) +_j 4/3 [SI] 19.99(a) v.- 1+k, <br /> H n2L [U.S.] 19.100(6) <br /> v2 <br /> H= + (v2 + v2n2L [U.S.] 19.99(b) 2g + 2.21R4/3 <br /> 2g ke (2g) 2.21R4/3 <br /> Table 19.9 Culvert Flow Classification Parameters <br /> flow hl -z h4 h4 culvert barrel location of kind of <br /> type D h, D slope flow control control <br /> 1 < 1.5 < 1.0 < 1.0 steep partial inlet critical depth <br /> 2 < 1.5 < 1.0 < 1.0 mild partial outlet critical depth <br /> 3 < 1.5 > 1.0 < 1.0 mild partial outlet backwater <br /> 4 > 1,0 > 1.0 any full outlet backwater <br /> 5 > 1.5 < 1.0 any partial inlet entrance geometry <br /> outlet entrance and barrel geometry <br /> g > 1.5 < 1.0 any full <br /> i. <br /> Figure 19.25 Culvert Flow Classifications <br /> type type <br /> 1 4 _ <br /> critical depth submerged <br /> at inlet outlet <br /> h,D z <1.5 L htD z > 1.0 h1 <br /> P' - --- ---------- h ha <br /> ha <1.0 h, he Q D d. -:0 0 ha p >1.0 z P ID -� <br /> 1z -------- ----_--Som- - - <br /> So >S� O -----Som -�� <br /> 2 5 <br /> critical depth rapid flow - -at outlet at inlet <br /> hill z L htD z 1.5 ht -- ----L---- <br /> <1.5 <br /> ---- <br /> N 1 0 h t �O D -� d� 0 h fl =1.0 z{Q2• D do -� Q ha <br /> a ---- ------SoT-- - - <br /> So <SC ----Som-- - - <br /> T <br /> 3 6. <br /> full flow .- <br /> tthro u hootflow free outfall <br /> throughout L <br /> h�D z <1.5 L htD z a1.5 h <br /> t <br /> ___ h <br /> 1.0 z�0 �D _� h3 ha <br /> has 1.0 <br /> 1h, fj D -� d h h 4 t zD ' <br /> h ----- ------- - (note that ---- ------5 17 -- <br /> r a So J� distance h3 o <br /> h� >1.0 is undefined) <br /> t <br /> PROFESSIONAL PUBLICATIONS , INC. <br />