Current research with navigation lock culvert valves

Transcription

1 Current research with navigation lock culvert valves Allen Hammack, PE US Army Corps of Engineers Engineer R&D Center Coastal and Hydraulics Laboratory November 2, 2017

2 Where are the locks controlled by the U.S Army Corps of Engineers? USACE has 193 lock sites 239 chambers Among the largest in the world Panama Canal St. Lawrence Seaway Recent valve studies Watts Bar John Day St. Lawrence Seaway Bankhead Holt Pickwick Each red mark is a navigation lock

3 Navigation locks generally share many common components Flow

4 Navigation locks generally share many common components Downstream miter gates Flow Chamber Upstream miter gates Lower pool Upper pool F/E ports F/E = filling and emptying Intake F/E culverts

5 Navigation locks generally share many common components Flow Fill valve Empty valve Empty valve Fill valve

6 Flow into and out of the chamber is controlled by valves Three types of lock culvert valves Flow is left to right in the figures Flow W PLAN Bulkhead Slot Vertical Lift Valve B FLOW Piezometric Gradeline h H L ELEVATION Vertical lift Piezometric Gradeline h H L R L B V b C c b V 2 Flow R L B V b C c b V 2 Flow Reverse tainter Conventional tainter

7 Flow into and out of the chamber is controlled by valves Three types of lock culvert valves Flow is left to right in the figures Flow W PLAN Bulkhead Slot Vertical Lift Valve B FLOW Piezometric Gradeline h H L ELEVATION Vertical lift Piezometric Gradeline h H L R L B V b C c b V 2 Flow R L B V b C c b V 2 Flow Reverse tainter Conventional tainter

8 Reverse tainter valve designs share many common components Ribs Skin plate Arm Trunnion Bottom lip

9 The flows in lock culverts near reverse tainter valves are complex h H L Piezometric Gradeline R L B V b C c b V 2 Flow

10 The flows in lock culverts near reverse tainter valves are complex Free-surface flow h H L Piezometric Gradeline Turbulent flow Potential flow R L Closed-conduit flow B V b C c b V 2 Flow

11 The flows in lock culverts near reverse tainter valves are complex Free-surface flow h H L Piezometric Gradeline Turbulent flow Potential flow R L Closed-conduit flow B V b C c b V 2 Flow

12 Reverse tainter valves have multiple problems at multiple locks Vibration Cracking Excessive uplift forces Cavitation Cavitation damage Valve crack Flow causing uplift

13 Cavitation causes severe damage to valve surfaces, which can be widespread

14 Cracking occurs at various locations on the valve Cracked valve arm connection Cracked valve skin Cracked valve arm

15 How can CHL help lessen the risk of these problems? Understand the flows Velocity field Physical model Pressure field Numerical model Turbulence model

16 Tests are conducted with particular changes made to a valve s shape

17 Reaction load data is obtained for each valve at various positions during operation Trunnion two components Hoist Hydraulic (calculated) Existing valve Modified valve

18 The flows around valves must be understood to better design valves The flows upstream and downstream of the valve are very different How can we make sense of the flow behavior downstream of the valve Quantify it - PIV

19 The flow near a model valve with dye released from upstream

20 The flow near a model valve with dye released from the valve well

21 The flow field velocity can be measured directly. Here is a small valve opening Instantaneous velocity Time-averaged velocity

22 Here is the flow field for a higher valve opening Instantaneous velocity Time-averaged velocity

23 The flow direction can also be directly measured Inst. velocity vectors Time-averaged velocity vectors

24 Other flow quantities such as vorticity can be calculated. Here is the small opening vorticity Instantaneous vorticity Time-averaged vorticity

25 Here are the vorticity results for a larger valve opening Instantaneous vorticity Time-averaged vorticity

26 How might cavitation be prevented? Cavitation damage is being observed in unexpected locations Cavitation is a low-pressure/high-velocity flow phenomenon Reduce velocities near skin plate during operation Existing geometry Plate added

27 What sort of modeling work can be done to address cracking? Scaled physical models? Vibrations don t scale well Large models are very expensive Structural scaling in Froudian model is impossible Numerical Hydraulic for loads Structural for stresses, strains, stress-intensity Structures - stresses Hydraulics - pressures

28 How can the recent work with lock culvert valves improve design and maintenance? Physical models are still the tool of choice Reproduces pressure and velocity fields near the valve Reaction loads (trunnion, hoist) Pressures along the culvert Can we move to numerical models? Cheaper and faster Provide field quantities that cannot be measured in a physical model Need to be validated because of the significant turbulence Measuring velocity fields in physical model Validate numerical model to velocity field and presume pressures, forces, and other quantities are accurate Could directly measure pressures on downstream side of valve skin plate

29 Collaborators on this research CHL Richard Stockstill John Hite David S. Smith Duncan Bryant Janie Vaughan Morgan Johnston Carlos Bislip Ben Burnham Marshall Thomas Keith Green DPW Zack Smith Trey Acuff Mickey Blackmon Chris Ables John Gullett Mark Daniels Chase Towne Hayden Skipper Jason Ables