wind engineering more gusty more gusty less gusty boundary layer wind tunnel c p = pressure at...
TRANSCRIPT
Wind Engineering for Façade Pressures in High Rise Towers
Bhami M Ilyas
Regional Business Manager
CPP, Inc.
Wind tunnel testing of New York World Trade Center Towers at CSU
in Fort Collins by Professor Jack Cermak in early 1960s
GRADIENT WIND
GRADIENT WIND
Zg = HEIGHT OF GRADIENT WIND
Ug= GRADIENT WIND SPEED
Zo= AERODYNAMIC ROUGHNESS
Z= Metres
1< Zo < 5m
SUBURBAN OPEN COUNTRY FLAT TERRAIN
GRADIENT WIND
GRADIENT WIND
URBAN
0.1< Zo < O.5m
0.01< Zo < O.05m
0.001< Zo <
O.005m
Classical boundary layer profiles
400 m
300 m
200 m
100 m
LESS GUSTY
MORE GUSTY
MORE GUSTY LESS GUSTY
CP =Pressure at Surface Tap
Reference Pressure
PTAP
For Bluff Bodies:
(CP)Full-Scale = (CP)Model
PREF = ½ V2
Pressure Coefficients – the basis of wind tunnel testing
Shaping Options
Softened corners
Tapering and setbacks
Varying cross-section shape
Spoilers
Porosity or openings
Vortex shedding
D = 1
D = 3
D = 5
CFD simulation of vortex shedding with three different cross-wind dimensions.
Note that this simulation also describes a constant cross-wind dimension but three different wind speeds (U = 5, 3, 1 from top to bottom)
3D Pressure Data PresentationFabrication and Testing
Test Model Design
3D Data Presentation
Presentation Model Design(engineers design how the data is used/zoned/presented)