P.V. Panel wind load effects

1. TEAM 12 P.V. Panel wind load effects Interim Review II March 2011 Arman Hemmati , Brady Zaiser, Chaneel Park, Jeff Symons, Katie Olver

2. Overview • Refresh • Wind TunnelExperiment Progress • CFD Progress

3. Refresh • Ideal angle of inclination is 51° • Too much weight for the roof? • Wind Tunnel testing – Experimental • Computational Fluid Dynamics (CFD) - Computational

4. Wind Tunnel – Where We Were • Designed model in SolidWorks • Talked to Mike Johnson • Increase the thickness of adjustable support rods • Panel to be made from MDF • Machining to be done at faculty shop

5. Wind Tunnel – Building the Model • Work order submitted February 4 • Started work on February 22 • ½” MDF was unavailable  substituted ¾” • Picked up on Friday February 25 • Some problems with design • Filler on welded parts means that parts don’t fit together • MDF panel is heavier than expected • Need to do force analysis

6. Wind Tunnel – Budget • Estimated cost of model • Materials: • ~$10 • Labour: • ~$25 • Total: • ~$35 • This is the only planned cost for our project • Extra costs may occur if something breaks or we do further tests

7. Wind Tunnel – Force Measurement • 2 load cells measure lift force & pitching moment • Drag plate measures drag • Old springs & strain gauge were not stiff enough • Rebuilt with load cell • Using LabView program to capture data • 3 data streams

8. Wind Tunnel – Wind Speed Measurement • Wind speed affects drag/lift force by: FD or L = CD or L ∙ ½ ρv2A • Cannot control speed in wind tunnel • Need to measure wind speed • Unable to capture digitally • Pressure too small for department’s pressure transducers • Hot wire anemometer fragile and expensive • Manually read dynamic pressure • Source of error • Average not instant

9. Wind Tunnel – Testing Parameters • Testing 3 parameters: • Wind direction • Panel angle • Panel height • Wind direction • How does the force on the panel change depending on the wind direction? • Front, back • 2 levels

10. Wind Tunnel – Testing Parameters • Panel angle • How does the force on the panel change as the angle increases? • In Calgary the ideal angle is 51° • Testing at: • 35°, 50°, 65° and 80° • 4 levels

11. Wind Tunnel – Testing Parameters • Panel height • How does the force on the panel change as the distance between the ground and the bottom of the panel increases? • Unable to use CFD for this • Testing at: • 0, 1”, 2”, …, 6” • 7 levels

12. Wind Tunnel – Testing Procedure • How many runs? • 2∙4∙7 = 56 runs per replication • 2 replications = 112 runs • Randomize run order • Lots of set-up between runs • How long will it take? • 5 min/run + daily set-up • Estimate 15 hours  1 week

13. Wind Tunnel - Schedule • Behind schedule • Hoped to test during reading week • Machining took longer than anticipated • Next 5 weeks: • 1 week testing • 1 week analysing results • 2 weeks further testing if necessary • 1 week preparing report

14. CFD - Update • Pressure Coefficient • Initially, CP > 1.5 • Now, CP < 1.1 • Biggest contributing factor: length of CV in front of panel

15. CFD - Verification • Vertical Flat Plate • Reference: “On the Flow of Air Behind an Inclined Flat Plate of Infinite Span” -Fage and Johansen, 1927.

17. CFD – Initial Results

19. CFD – Initial Results

20. CFD – Next Step • Determine why pressure increases with finer mesh • Overcome convergence problems • Try different solution models

21. www.ucalgary.ca/deloprec