Page - 1537 - in Book of Full Papers - Symposium Hydro Engineering

𝑉 = 1 𝑛 𝑅 2 3𝑆 1 2 (3) Where V= Velocity of water in the tunnel in m/s n= Coefficient of rugocity for unlined tunnels may range from 0.04 to .06 R= Hydraulic radius in m, for sections other than circular R = 4 S= Longitudinal slope 3.2. HEAD LOSS - Following losses may be expected for flow in diversion Tunnel:  Head loss in approach channel, if tunnel is located away from reservoir  Head loss at intake entrance ℎ𝑒 = 𝑘 𝑒 𝑉 2𝑔 2 (4) Where ℎ𝑒 , 𝐾 𝑒 are head loss and loss coefficient s respectively 𝐾 𝑒 = 0.16 for square bell mouth entrance = 0.03 for circular bell mouth = 0.1 for gate wall rounded corners Head loss due to gradual contraction ℎ𝑒 = 𝐾 𝑒 ( 𝑉 2 2 2𝑔 − 𝑉 1 2 2𝑔 ) (5) Here 𝐾 𝑒 =0.10 Other losses as at bends, transitions, etc. Head loss due to tunnel friction, calculated with the help of Darcy Weisbach resistance equation: 𝐻 𝑒 𝑎 𝑑 𝑙 𝑜 𝑠 𝑠 = ℎ𝑓 = 𝑓 𝐿 𝑉 2 2𝑔 𝐷 Where ℎ𝑓 = Head loss in m 𝑓 = Friction factor 𝐿 = Length of stretch 1537