Wind Tunnel Design Replicating Offshore Winds American Offshore Energy

Wind Parameters Variable Speed Uniformity Direction Range: 0 – 20 m/s Evenly distributed wind speed throughout section Direction Straight flow through test chamber

Test Chamber Largest achievable square section To optimize initial flow coverage from fan Test Specimen Estimated Size: (Ø100’ x 200’) Scaled Sizes 1:8 (Ø150” x 300”) 1:24 (Ø50” x 100”) 1:30 (Ø40” x 80”) 1:50 (Ø24” x 48”)

Trailer Selection Parameters Limits Maximum Test Chamber Size Average Inside Area: 92” x 92” Minimum Length Required: 16’ (192”) Cost Range: $1,500 – $9,000 Ideal Additional Options: Electrical Power Maximum Area Low Cost Dry Van Trailers are Ideal

Trailer Purchasing Options Commercial Truck Trader Username: pmehan@newwayairbearings.com Password: newway123! Truck Paper (Website for auction) Arthur Trovei & Sons, Inc.

Available Trucks $2500 Reefer Trailer (45’ Length x 96” Width) No Title (next available $5,500.00)

Available Trucks $1800 (96” x 100” x 40’)

Available Trailers $2750 (no dimensions provided)

Trailer Aesthetic

Design 1 Layout (Blower Tunnel)

Design 2 Layout (Suck Down Tunnel)

Design 3 Layout (Classical Contraction)

Diffuser Requires approximately 11.5’ to maintain diffusion angle of 10 degrees Could be framed with wood and have a sheet metal surface Inexpensive and contains flow as a stream with a boundary layer (prevents flow separation) Removes large low pressure areas

Screens Screens placed from coarse to fine mesh Located up and downstream from honeycomb Used to create a high pressure area that evenly distributes the flow throughout the cross-section (reduce axial turbulence) Finest screen (closest to test chamber) must be free from damage as it is the final flow conditioner

Screens TWP Inc. Approximately $2,000 for 5 different screens moving from coarse to fine ($400 per screen) Requires soldering wire meshes together Stainless Steel (plain or galvanized steel available for cheaper)

Screens Drenth $6200 for 5 sheets of 96” x 96” Section Ø 0.20 mm Wire and 10 x 10 / cm gap 64% Open Surface (Cheaper per meter if ordered bulk) Advantages: Can be ordered full size

Honeycomb Air Straightener Straighteners used to reduce swirling created from fan (lateral turbulence) Creates small axial turbulence which is mitigated from post-honeycomb screens Optimal diameter to length ratio is 6 – 8.

Honeycomb Air Straightener Ruskin AS 100 Honeycomb Straightening Section 0.50” Cell Size and 3” Deep (Ratio of 6) Free Area: 97% Velocity Range: 0-25.4 m/s Max Size: 48” x 96” per section Pressure Drop: 0.06” wc (15Pa) @ 1000 FPM (5.1 m/s) $3,500 for two full size sections (96” x 96”)

Honeycomb Air Straightener McMaster Carr Honeycomb Core $3,456 for 32 (28” x 48”) pieces Same specifications and material as Ruskin but smaller sections and limited to 3/4” depth Design Option Use Ruskin for two large pieces Use McMaster to fill gaps to match test section

Fan Approximate Axial Fan selection made by Howden that can supply the appropriate CFM Sizing needs to be fine tuned to final design to account for static pressure at startup Estimated cost $12,000.00

VFD Waiting to hear quote from Howden Approximate Cost is $6,000.00 Critical to flow velocity control, efficiency, and noise mitigation

Electrical Connection $613 Circuit Breaker 125 Amps, 3 Pole, 277/480Vac

Instrumentation Pitot Tube Air Flow Meter Hot Wire Anemometer Voltmeter Transducers

Pitot Tube Uses differential pressure (total and static) to calculate velocity Pressure Transducer across the two outlets takes the measurement For velocity to have complete 0.5 m/s resolution, the transducer must have at least 0.003 inch WC resolution (0.01 resolution is acceptable after 4 m/s).

Pitot Tube Dwyer 160-48 Dwyer 160-60 Gland A-159 5/16” Diameter, 48-5/8” insertion length, 1/4” Diameter Outlet Can Traverse entire cross section $91.00 Dwyer 160-60 121.00 with insertion to 60” Gland A-159 1/2” Male NPT $28 (approximately quantity: 8)

Pitot Tube

Pressure Transducer

Miscellaneous Fasteners Plugs/Wires/Electrical Components Lighting Tables/Control Center Work Station Paint/Graphics/Aesthetics

Sum of Costs Item Cost Fan $12,000.00 VFD $6,000.00 Circuit Breaker $650.00 Trailer $3,000.00 Wire Mesh Screens $2,000.00 Honeycomb Air Straightener $3,500.00 Instrumentation $25,000.00 Boundary Material (Diffuser) $1,600.00 Labor $10,000.00 Miscellaneous $1,000.00 Total $64,750.00

Vertical Axis Wind Turbine Maximum angular velocity is limited by speed of wind Allows for wide base structure that easily floats offshore Offshore wind provides higher quality energy

Raw Data/Equations Pressure Calculations (Bernoulli)

Raw Data/Equations Power Generation

Raw Data/Equations Data for Transducer Resolution

Citation Links https://www.princeton.edu/~asmits/Bicycle_web/Bernoulli.html https://en.wikipedia.org/wiki/Vertical_axis_wind_turbine