1 - Alaska Energy Data Inventory

friction values were obtained from the Von Karman-Prandtl smooth pipe lineat the appropriate Reynolds Number (HOC chart 224-1) while the maximumfriction values were based on the Rouse rough pipe limit which in this casewere equal to or greater than the values obtained from the VonKarman-Prandtl fully rough equation.See paragraph 1.03 8(4) below for afurther discussion of the Rouse rough pipe limit versus Von Karman-Prandtlfor determ"ining maximum losses.for the concrete-lined section of the power tunnels.The following friction factors were usedCond it i onMaximum LossesExpected LossesMinimum LossesOarcy-Weisbach IIfll0.01600.01370.0093IVJanning "n"0.01340.01240.0102Friction values were taken directly from the IIMoodyll diagram with theVon Karmon-Prandtl Smooth Pipe Equation and the Rouse Equation being usedf.or an occasional check.As the design of the Crater Lake Project proceeded, foundationinvestigations provided more information on the rock conditions along theproposed tunnel alinement. As a result, we now anticipate that there willbe only 125 ft of concrete lining along with approximately 920 ft ofshotcrete 1 ining.Calculations were made comparing the hydraul ic lossesfor 800 ft of concrete-lined tunnel with the losses that would occur for acombined total of 1,045 ft of concrete and shotcrete lining. Thecalculations sowed that with an average discharge of 335 ft 3 /s, usingexpected losses, the total difference in head loss for the differentcondit ions was on ly 0.23 ft. The shotcrete-concrete comb i nat i on resu ltedin smaller losses than the concrete section. For the maximum discharge of518 ft 3 /s the head loss difference was 0.44 ft which represents only 2.2pct of the total losses from intake to surge tank.This was felt to beinsignificant and no changes were made in the orig"inal hydraulic losscalculations.81-18