P.V. PANEL WIND LOAD EFFECTS A PRIL 2011 Arman Hemmati, Brady Zaiser, Chaneel Park, Jeff Symons, Katie Olver Winter Project Review TEAM 12

April Design Review #5: DeLoPREC Overview Refresh CFD Progress & Result Wind-Tunnel Experiment Progress & Result 1

April Design Review #5: DeLoPREC Refresh 2 Ideal angle of inclination is 51° Too much weight for the roof? Wind-Tunnel testing – Experimental Computational Fluid Dynamics (CFD) - Computational

April Design Review #5: DeLoPREC CFD – Software Packages 3 ANSYS CFX ▫Employing Finite Element Method (FEM) ▫Best in Single Physics Modeling ▫Mostly used for modeling of Solids ▫University of Calgary Licensing Comsol Multiphysics ▫Works on basis of FEM ▫Multi-physical modeling ▫Best suited for modeling of Fluids, Stationary Solids ▫Shell Canada Licensing

April Design Review #5: DeLoPREC 4 Computational – 2D vs. 3D Modeling 1.Two-Dimensional (2D) Models ▫Easier to develop, evaluate, and understand ▫Typically the start of an analysis ▫Provides a general overview to the forces expected in the wind tunnel 2.Three-Dimensional (3D) Models ▫More Difficult to set-up, and develop ▫More powerful computers required ▫More realistic model of the actual phenomena ▫Typically used to compare to the wind tunnel testing

April Design Review #5: DeLoPREC CFD – Expectations 5 1.Establish a functional and feasible model a)2-Dimensional b)C.V. size (inlet and outlet buffer zones) c)Turbulence Model – k-epsilon, RNG k-epsilon 2.Confirm the credibility of the model a)Pressure Coefficient (C P ) – Front and Rear Surfaces b)C L and C D c)Convergence 3.Parameter variation study a)Panel angle of attack b)Panel – Rooftop separation distance c)Wind speed / Reynolds Number d)Number of panel in series Interconnected

April Design Review #5: DeLoPREC CFD – Validation 6 Open Channel Flow: Geometry – Horizontal Open Channel Simple Physics – Laminar flow Wall (No Slip) Outlet Inlet Velocity (m/s) Height (m)

April Design Review #5: DeLoPREC CFD – Validation 7 Pressure Coefficient Vertical Flat Plate

April Design Review #5: DeLoPREC CFD – Steady Convergence in CFX 8

April Design Review #5: DeLoPREC CFD - Verification Reference: “On the Flow of Air Behind an Inclined Flat Plate of Infinite Span” -Fage and Johansen,

April Design Review #5: DeLoPREC 10

April Design Review #5: DeLoPREC CFD – Initial Results 11

April Design Review #5: DeLoPREC 12

April Design Review #5: DeLoPREC CFD – Unsteady Simulations 13

April Design Review #5: DeLoPREC CFD – Unsteady Simulations 14

April Design Review #5: DeLoPREC CFD – Now What? Can not get rear of panel to match research Panel Angle: 10°, 30°, 51°, 70°, 90° Flow Type: Steady, Unsteady Turbulence Model: k-ε, RNG k-ε 15

April Design Review #5: DeLoPREC CFD – Unsteady Data Collection Time steps set to 0.01s Pressure data recorded every 5 time steps Averaged over 10s 10s/0.05s = 200 pressure plots X 10 unsteady simulations = 2000 pressure plots to export from CFX into Excel! The solution: Macros! 16

April Design Review #5: DeLoPREC 17

April Design Review #5: DeLoPREC CFD – Drag Results 18

April Design Review #5: DeLoPREC CFD – Lift Results 19

April Design Review #5: DeLoPREC CFD - Strouhal Number Relationship for vortex shedding frequency Flat Plate, St = 0.16  f= 2.8 Hz CFX gives St = 0.22  f= 3.94 Hz Error = 41% 20

April Design Review #5: DeLoPREC CFD - Recommendations Use 3D over 2D ▫Other turbulence models only work in 3D Use specialized turbulence models ▫DES, LES, SAS 21

April Design Review #5: DeLoPREC Experimental Schedule 22

April Design Review #5: DeLoPREC Wind Tunnel – Schedule Delay 23 Manufacturing order to the faculty machine shop submitted February 4 Drag Plate and DAQs system faults found during preliminary tests. (Hardware line-up problem and software problem). Adjustment in process. Products finished by Mar. 11 th, but software could not be improved. Has to take 3 different measurement assuming wind velocity is constant.

April Design Review #5: DeLoPREC Wind Tunnel – Budget Drag plate, wind tunnel, DAQs system borrowed for free from the department 24 Panel ModelDrag PlateWind Tunnel DAQs Material:$10.00$0.00$12.87$0.00 Labour:$25.00$0.00 Total:$35.00$0.00$12.87$0.00

April Design Review #5: DeLoPREC Wind tunnel – Drag Plate One load cell (max. 50lbs) installed inside the drag plate Two new holes drilled and threaded exactly in the centre 25

April Design Review #5: DeLoPREC Wind tunnel - DAQs 3 InterfaceTM load cells(25lbs, 50lbs) NI 9237(4 Channels) NI cDAQ – 9172 NI LabView 2009 with customized vi file 26

April Design Review #5: DeLoPREC Wind tunnel – tunnel systems Straight, rectangular wind tunnel Two turbines with speed control damper Anemometer 27

April Design Review #5: DeLoPREC Wind tunnel – model assembly Plastic lamination on the panel Final Assembly in the wind tunnel Wooden boards on the sides of the drag plate 28

April Design Review #5: DeLoPREC Wind tunnel – final apparatus 29 a A h G l c b d

April Design Review #5: DeLoPREC Wind tunnel – testing parameters 30 TestsNumber Wind DirectionFront, Back2 Panel Angle35°, 51°, 65°, 79°4 Panel Gap0 ~ 15cm14 Total112 In the result, we had total of 144 runs including repetition & make-ups for mistakes. For each run we had to take 3 different measurement, resulting in total of 432 data files to analyze.

April Design Review #5: DeLoPREC Experimental Result – Drag 31

April Design Review #5: DeLoPREC Experimental Result - Drag 32

April Design Review #5: DeLoPREC Experimental Result - Lift 33

April Design Review #5: DeLoPREC Experimental Result - Lift 34

April Design Review #5: DeLoPREC Comparison to Theoretical Values 35

April Design Review #5: DeLoPREC Experimental Verification Load cell credibility -> Fish scale Verification Effect of built up pressure on drag plate -> Fish scale with weight Lift and Drag Relationship:, especially at higher angle. 36

April Design Review #5: DeLoPREC Effect of Pressure on Measurement ExpFish Scale(kg)Load Cell(lbs)Fish Scale(N)Load Cell(N)% Error Drag % Drag Drag 3(with weight) % Drag 4(with weight) Drag 5(with weight) % Drag 6(with weight) Load Cell(lbs)(Without weight)Load Cell(lbs)(With Weight)% Error Load cell % Load Cell %

April Design Review #5: DeLoPREC Load Cell Credibility 38 Fish Scale(N)Load Cell(N)Sum% Error Load Cell % Load Cell

April Design Review #5: DeLoPREC Real PV Panel – Worst Case Scenario Wind Blowing from the Front ▫Max CoD: > 29m/s ▫Max CoL: > 29m/s Wind Blowing from the Back ▫Max CoD: > 29m/s ▫Max CoL: > m/s Required Mass of Concrete Blocks: kg -> 3 Blocks (240kg) / Panels Maximum Load applied to Roof: 2.81kN/Panels 39

April Design Review #5: DeLoPREC Conclusion Measurements from our DAQs is reliable However, there are results we cannot understand fully. Sources of error could be: Velocity profile and wall effects. 40

April Design Review #5: DeLoPREC