![hec ras manual hec ras manual](https://slidetodoc.com/presentation_image/2b2eeb7e36540befbc1d12b1064a3fd7/image-2.jpg)
and pressure force exerted by banks Slide 17 Momentum Equation Sum of forces on the C.V. F e = contraction/expansion force due to abrupt changes in the channel cross-section F w = wind shear force due to frictional resistance of wind at the water surface F p = unbalanced pressure forces due to hydrostatic forces on the left and right hand side of the C.V. F f = friction force due to shear stress along the bottom and sides of the C.V. Elevation View Plan View F g = Gravity force due to weight of water in the C.V. Momentum stored within the C.V Momentum flow across the C. Change in mass Reynolds transport theorem Slide 15 Momentum Equation From Newtons 2 nd Law: Net force = time rate of change of momentum Sum of forces on the C.V. Mannings equation is used to describe resistance effects The fluid is incompressible Slide 14 Continuity Equation Q = inflow to the control volume q = lateral inflow Elevation View Plan View Rate of change of flow with distance Outflow from the C.V. 2-1 to 2-12 Applied Hydrology, Sections 10-1 and 10-2 Slide 2 Flood Inundation Slide 3 Floodplain Delineation Slide 4 Steady Flow Solution Slide 5 Right OverbankLeft Overbank Channel centerline and banklines Cross-section One-Dimensional Flow Computations Slide 6 Flow Conveyance, K Left OverbankRight OverbankChannel Slide 7 Reach Lengths (1) (2) L ob R ob L ch Floodplain Left to Right looking downstream Slide 8 Energy Head Loss Slide 9 Velocity Coefficient, Slide 10 Solving Steady Flow Equations 1.All conditions at (1) are known, Q is known 2.Select h 2 3.compute Y 2, V 2, K 2, S f, h e 4.Using energy equation (A), compute h 2 5.Compare new h 2 with the value assumed in Step 2, and repeat until convergence occurs h2h2 (2) (1) h1h1 Q is known throughout reach (A) Slide 11 Flow Computations Reach 2 Reach 3 Reach 1 Start at the downstream end (for subcritical flow) Treat each reach separately Compute h upstream, one cross- section at a time Use computed h values to delineate the floodplain Slide 12 Floodplain Delineation Slide 13 Unsteady Flow Routing in Open Channels Flow is one-dimensional Hydrostatic pressure prevails and vertical accelerations are negligible Streamline curvature is small.
#HEC RAS MANUAL MANUAL#
Hydraulic Routing in Rivers Reference: HEC-RAS Hydraulic Reference Manual, Version 4.1, Chapters 1 and 2 Reading: HEC-RAS Manual pp.