P.V. Panel wind load effects

P.V. PANEL WIND LOAD EFFECTS

NOVEMBER 2010

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

Design Review #1

NOVEMBER - 2010Design Review #1: DeLoPREC

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Overview

• Introduction (Katie)

• Objectives (Brady)

• Wind Tunnel Tests (Jeff)

• Computational Analysis (Arman)

• What’s Next (Chaneel)


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Introduction - DIY Frames at ENMAX


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Introduction – Renusol ConSole

- Plastic Mounting System


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Introduction – Problem

• Most efficient sun capture at 51°

• Higher angle means greater aerodynamic forces

• More 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


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Objectives – Project Overview

1. Determine amount of ballast required

2. Determine downward force induced by wind▫ Total load on roof is sum of 1. and 2.

3. Determine total load for two different frames▫ How to minimize load?


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Objectives – Functional Requirements

1. Effect of Wind Speed▫ Proportional, or…?

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

3. Effect of Wind Direction▫ Front or back

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

5. Repeat for Second Frame Design


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Wind Tunnel – Facility Specifications

• Environmental Wind Tunnel▫ Located in Engineering Building

• Size and dimensions of the Wind Tunnel▫ Required to correctly design the scaled down model

• Full capability of the Wind Tunnel▫ Necessary to determine the reasonable testing wind

speed.


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Wind Tunnel – Model Scaling/Building

1. Constructing a suitable model (6 linear panel array)▫ The size of the model must correspond to the

dimensions of the wind tunnel▫ What material should be used as a PV panel substitute▫ Require a base frame for the model to rest upon

2. Methods for analyzing the force on the panel▫ Force Receiving Base▫ Pressure Distribution is not a concern▫ Force transducers or load cells considered

(although potentially expensive)


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Wind Tunnel – Testing (conceptual)

1. Height of the panel from the roof (Frame Bottom Opening)▫ Least Loads: Test the model at various heights

2. Variation of wind speed▫ Wind Speed Effect: The relationship between wind

speed, drag/lift forces, and additional load on the roof

3. Wind angle of attack▫ Flexible Model: The model is angled to represent

varying wind angle of attack▫ Methods for model force Analysis

▫ Methods for model force Analysis


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Computational – Software Packages

• 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


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Computational – 2D vs. 3D Modeling

Courtesy of COMSOL Multiphysics

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


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What’s Next – Conclusion

1. Current Stage in the Design Process▫ Direction is set, details required

2. Plan on Wind Tunnel Test▫ Model design details▫ Method of measurement: Literature research

3. Plan on CFD▫ Program and computer availability▫ Importing CAD model

4. Revised Frame Design▫ Only if current design fails


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References

• Renusol ConSole Manual 9/2009

• COMSOL Multiphysics Website

• ANSYS Website


www.ucalgary.ca/deloprec

http://www.ucalgary.ca/deloprec

http://www.ucalgary.ca/deloprec

Documents

P.V. Panel wind load effects