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Numerical and Wind-Tunnel Simulation of Wind Loads on Smooth and Rough Domes

R.N. MeroneyC.W. Letchford

P.P. Sarkar

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Powerpoint Presentations!

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Structural Domes

Domes are commonly used to enclose large spaces because of their structural efficiency and economic benefit.

Domes are excellent at resisting symmetric loading, but

Asymmetric loading may cause structural distress and failure.

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Domed Sports Halls & Stadiums

Houston Astrodome

Hubert H. HumphreyMetro-Dome, Min

Little Sports Palace, Rome

Pepsi Center, Denver

Sun Dome, Fukui, Japan

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Assembly Hall Dome

Assembly Hall, U. ofIllinois Urbana/Champ

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Domed Public Buildings

^ Public Exhibition HallsMillennium Dome, London,320 m diameter, 80,000 sq m floor space

Museums and Halls,Barlow Planetarium, CA

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Inflated Domes

US Pavilion, Osaka Exposition 1970

Carrier Stadium, Syracuse University

Georgia Dome, Atlanta Silverdome, Pontiac, MI

RCA (Hoosier) DomeIndianapolis, IN

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Inflated Domes (contd)

Tokyo Dome“Big Egg” Stadium,Tokyo, Japan

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Bulk Storage: Dust Supression, Water and Wastewater Treatment Covers

Temcor Aluminum DomesTriangulated space truss system with

triangulated panels

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Bulk Storage: Coke Piles

Pittsburgh, CA Marine Terminal Coke Storage Domes Three 55 m (180 ft) diameter hemispheres

Los Angeles, CA Export Terminal Coke Storage Domes ConstructionTwo 73 m (240 ft) diameter hemispheres, Shotcrete applied to interior of inflated airform mounted on footer and stem wall

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Rough Surface Hemispheres

Sometimes construction technique leaves surface texture rough!

WIND RESEARCH

& DESIGN

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CFD Validation Using Physical ModelingVERIFICATION BEFORE PROGNOSTICATION

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Wind Effects on Hemispherical Domes

Inflated domes require internal pressures exceeding external pressures to avoid buckling.

Internal pressures must not be too large or excessive membrane or tensile forces occur, and membrane tears.

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Wind-tunnel Study of Inflated Domes

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Newman, Ganguli and Shrivastava (1984) studied pressure distributions on three inflatable domes in a boundary layer.

H/D = 0.5, 0.37 & 0.25, H/=0.12-0.13, U=7.5 m/s, Re=UD/=226,000

FEM calculations show buckling occurs on plane of symmetry and upwind when the internal inflation pressures < 0.7-0.44 of the dynamic pressure at the dome top.

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CSU WEFL Wind Tunnel Experiment

Pressure Scanner

Pressure Transducer

CSU WEFL Industrial Aerodynamics Wind Tunnel

PC-NT Computer

Postprocess Software

Hot Film Anemometer

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Wind-Tunnel Initial Conditions

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m

2 m

1.8 m

Grid: 86,000 cells

Velocity Contours:Umax = 15 m/s

Z = 1m

Z = 0.8 m

ASCE 7-98C

Windtunnel

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Grid Systems: One and Two Domes

18,000 Cells 33,000 Cells 16,400 Cells

43,000 Cells

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Hemisphere Grids

Boundary layer & Hex Grid Boundary layer & Tet Grid

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Velocity & Turbulence Profiles:Single Dome Comparisons

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Single Dome Comparisons: Pressure Profiles

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Single Dome Comparisons: Reynolds Number Variation

Reynolds Number = (U H/) = 185,000

Reynolds Number = (U H/) = 1,440,000

Conclusion: No significant difference

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Single Dome Comparisons:

Turbulence Models

Standard kappa-epsilon model (2 equations)

Reynolds stress model (7 equations)

Spalart Allmaras model (1 equation)

Conclusion: No significant difference

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Single Dome Comparisons: Pressure Profiles

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Single Dome Comparisons: Smooth vs Rough

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Double Dome ComparisonsApproach wind at 90o

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Double Dome Comparisons

Approach wind at 90o

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Surface Pressures: Angles 0o, 45o & 90o

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Pressure Coefficient Contours:

Experimental vs Numerical: Approach wind at 0o

Cp Contours: numerical

Cp Contours: experimental

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Double Dome Comparisons

Approach wind at 0o

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Double Dome Comparisons

Approach wind at 45o

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Pressure Coefficient Contours: Experimental vs Numerical:

Approach wind at 90o

Cp Contours: numerical

Cp Contours: experimental

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Double Dome Comparisons

Approach wind at 90o

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Conclusions

CFD calculations reproduced mean Cp behavior over smooth, rough and paired domes.

CFD calculations using k-, RNG, and Rey turbulence models gave similar results.

CFD calculations at high and low Reynolds numbers gave similar results.

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WHALE WATCHING IS NOT AN EMERGENCY KEEP DRIVING

GOOD LUCK

Approaching the End

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The End