P.V. PANEL WIND LOAD EFFECTS

MARCH 2011

Arman Hemmati , Brady Zaiser, Chaneel Park, Jeff Symons, Katie Olver

In-Class Presentation

TEAM 12

MARCH- 2011In-Class Presentation: DeLoPREC

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Introduction – Problem

• Most efficient sun capture at 51°

• Higher angle means greater aerodynamic forces

• Ballast required to hold the panel down

• Too much weight for the roof?

• Want to better understand wind loads on PV panels:

▫ Wind Tunnel Testing▫ Computational (CFD) Analysis

MARCH- 2011In-Class Presentation: DeLoPREC

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Objectives – Functional Requirements

1. Effect of Wind Direction▫ Front or back

2. Effect of Panel Tilt ▫ Preferred angle is 51°

3. Proximity of Panel to the Ground▫ Should reduce drag to a point

MARCH- 2011In-Class Presentation: DeLoPREC

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Wind Tunnel – Test Apparatus

MARCH- 2011In-Class Presentation: DeLoPREC

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Wind Tunnel – Testing Parameters

•Wind direction▫How does the force on the panel change

depending on the wind direction? Front, back

▫2 levels

MARCH- 2011In-Class Presentation: DeLoPREC

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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

MARCH- 2011In-Class Presentation: DeLoPREC

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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

MARCH- 2011In-Class Presentation: DeLoPREC

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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

MARCH- 2011In-Class Presentation: DeLoPREC

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Computational Fluid Dynamics

• 2D Simulations• Using Comsol Multiphysics and Ansys CFX

MARCH- 2011In-Class Presentation: DeLoPREC

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CFD - Verification

• Results recorded in ratios (CL, CD, CP)

• Vertical Flat Plate

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

MARCH- 2011In-Class Presentation: DeLoPREC

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13 13.5 14 14.5 15 15.5

-1.6

-1.1

-0.6

-0.1

0.4

0.9

FrontBack

Distance Along Y-Axis (m)

Pre

ssure

(P

a)

MARCH- 2011In-Class Presentation: DeLoPREC

www.ucalgary.ca/deloprec