FLOOD06499 - Laserfiche WebLink

Home Browse Search

Table 4 Data for McNary Second Powerhouse Study 1. Upstream boundary condition: a. Spillway: Q = 7000 cms (250,000 cfs) for calibration runs Q = 0 for production runs b. Existing powerhouse: Q = 6500 cms (230,000 Cf5) c. Second powerhouse: Q = 7000 cms (250,000 cfs) 2. Downstream boundary condition: Water surface elevation = 82.4 m (270.3 ft) MSL* 3. All other boundaries: Either tangential flow or stagnation points 1 2 1 2 4. Roughness: Chezy C = 55 m J Jsec (100 ft J Jsec) 5. Turbulent exchange coefficients: Varied with element size from 4.8 to 14.4 m2Jsec (50 to 150 ft2Jsec) *For production runs in which total river discharge was 13600 cm5 (480,000 cfs). This elevation was varied according to a known stage-discharge relationship for other discharges. A vector plotting routine was used to display simulated flow fields. Two such plots are shown on Figs. 7 and 8. Plots of this type are considered essential for interpreting and analyzing complex flow fields. Continuity errors were generally less than !5% with the exception of the constriction near the downstream boundary where errors were on the order of -15%. If future detailed studies are made, and velocities in that area become important, more network detail will be provided. ;~~J: U.O fn _- -- tllUl.(f;"'"~l.1f ,. -.... /" ,. --..... - - -- ............ ~ "..-- -- - - -- -........ ...... '..... , //- - --_........_~ . - // - ------------_.........~ --- - ',"// - ----------- -. -........... -7//"-- -------------- ---------------~----- -- -- - ----- ----............-:::::.--- -- ----- ------------------- - - -- - -- ---------- ------ --- --- - - ~.=:=::.::=:::::~=:--=--:=--=---~~~~:::::::~ :-::::/~~__:~: :=...~ ~=--_~.c:_=:~~~~ ---- ---~ ~~ ----. -- - ...-- -- \ --- -- - , Figure 7 Velocities for Spillwqy Q = 7000 ems (250,000 cfs), Existing Powerhouse Q = 6500 ems (230,000 cfs), Slip Boundary Conditions "