Characterization of the wind loads and flow fields around a gable-roof building model in tornado-like winds

An experimental study was conducted to quantify the characteristics of a tornado-like vortex and to reveal the dynamics of the flow-structure interactions between a low-rise, gable-roof building model and swirling, turbulent tornado-like winds. The experimental work was conducted by using a large-scale tornado simulator located in the Aerospace Engineering Department of Iowa State University. In addition to measuring the pressure distributions and resultant wind loads acting on the building model, a digital Particle Image Velocimetry system was used to conduct detailed flow field measurements to quantify the evolution of the unsteady vortices and turbulent flow structures around the gable-roof building model in tornado-like winds. The effects of important parameters, such as the distance between the centers of the tornado-like vortex and the test model and the orientation angles of the building model related to the tornado-like vortex, on the evolutions of the wake vortices and turbulent flow structures around the gable-roof building model as well as the wind loads induced by the tornado-like vortex were assessed quantitatively. The detailed flow field measurements were correlated with the surface pressure and wind load measurements to elucidate the underlying physics to gain further insight into flow-structure interactions between the gable-roof building model and tornado-like winds in order to provide more accurate prediction of wind damage potential to built structures.

[1]  Neil B. Ward,et al.  The Exploration of Certain Features of Tornado Dynamics Using a Laboratory Model , 1972 .

[2]  Charles A. Doswell,et al.  The Tornado : its structure, dynamics, prediction, and hazards , 1993 .

[3]  Chris Letchford,et al.  Physical simulation of a single-celled tornado-like vortex, Part A: Flow field characterization , 2008 .

[4]  Jack E. Cermak,et al.  Applications of Fluid Mechanics to Wind Engineering—A Freeman Scholar Lecture , 1975 .

[5]  Brian F. Farrell,et al.  The Structure and Dynamics of Tornado-Like Vortices , 1999 .

[6]  J. Hunt,et al.  Kinematical studies of the flows around free or surface-mounted obstacles; applying topology to flow visualization , 1978, Journal of Fluid Mechanics.

[7]  C. Tropea,et al.  The Flow Around Surface-Mounted, Prismatic Obstacles Placed in a Fully Developed Channel Flow (Data Bank Contribution) , 1993 .

[8]  Zifeng Yang,et al.  Experimental investigations on complex vortex flows using advanced flow diagnostic techniques , 2009 .

[9]  Curtis R. Alexander,et al.  The 30 May 1998 Spencer, South Dakota, Storm. Part II: Comparison of Observed Damage and Radar-Derived Winds in the Tornadoes , 2005 .

[10]  Robert B. Wilhelmson,et al.  The Numerical Simulation of Nonsupercell Tornadogenesis. Part II: Evolution of a Family of Tornadoes along a Weak Outflow Boundary , 1997 .

[11]  Theodore Stathopoulos,et al.  Wind pressure provisions for gable roofs of intermediate roof slope , 2001 .

[12]  Charles A. Doswell,et al.  Normalized Damage from Major Tornadoes in the United States: 1890 1999 , 2001 .

[13]  Partha P. Sarkar,et al.  Tornado-induced wind loads on a low-rise building , 2010 .

[14]  Makoto Kanda,et al.  Characteristics of fluctuating wind pressure on long low-rise buildings with gable roofs , 1993 .

[15]  Fred L. Haan,et al.  Transient Loads on Buildings in Microburst and Tornado Winds , 2006 .

[16]  Charles A. Doswell,et al.  The Tornadoes of 3 May 1999: Event Verification in Central Oklahoma and Related Issues , 2002 .

[17]  Robert B. Wilhelmson,et al.  The Numerical Simulation of Non-Supercell Tornadogenesis. Part I: Initiation and Evolution of Pretornadic Misocyclone Circulations along a Dry Outflow Boundary , 1997 .

[18]  Hui Hu,et al.  Visualization of flow structures around a gable-roofed building model in tornado-like winds , 2010, J. Vis..

[19]  John T. Snow,et al.  Tornado Vortex Simulation at Purdue University , 1977 .

[20]  Richard L. Thompson,et al.  A Simple and Flexible Method for Ranking Severe Weather Events , 2006 .

[21]  Tomer Anor,et al.  Direct numerical simulation of turbulent flow around a wall-mounted cube: spatio-temporal evolution of large-scale vortices , 2006, Journal of Fluid Mechanics.

[22]  Joel H. Ferziger,et al.  A fluid mechanicians view of wind engineering: Large eddy simulation of flow past a cubic obstacle , 1997 .

[23]  Chris Letchford,et al.  Physical Simulation of a Single-Celled Tornado-Like Vortex, Part B: Wind Loading on a Cubical Model , 2008 .

[24]  Joseph H. Golden,et al.  A Review of Tornado Observations , 2013 .

[25]  Timothy A. Reinhold,et al.  Field measurement and wind tunnel simulation of hurricane wind loads on a single family dwelling , 2009 .

[26]  Bruce D. Lee,et al.  The Numerical Simulation of Non-Supercell Tornadogenesis , 1995 .

[27]  Partha P. Sarkar,et al.  Design, construction and performance of a large tornado simulator for wind engineering applications , 2008 .

[28]  Swarndeep Gill,et al.  Finescale Radar Observations of the Dimmitt, Texas (2 June 1995), Tornado , 2000 .

[29]  Erik N. Rasmussen,et al.  Direct Surface Thermodynamic Observations within the Rear-Flank Downdrafts of Nontornadic and Tornadic Supercells , 2002 .

[30]  Theodore Stathopoulos,et al.  Wind force coefficients for designing free-standing canopy roofs , 2007 .

[31]  A. Robins,et al.  The flow around a surface-mounted cube in uniform and turbulent streams , 1977, Journal of Fluid Mechanics.

[32]  M. C. Jischke,et al.  Laboratory simulation of tornadic wind loads on a rectangular model structure , 1983 .

[33]  Kishor C. Mehta,et al.  The Enhanced Fujita Scale: For Use Beyond Tornadoes? , 2009 .

[34]  J. M. Sousa.  Turbulent flow around a surface-mounted obstacle using 2D-3C DPIV , 2002 .

[35]  Jon A. Peterka,et al.  Area-average peak pressures in a gable roof vortex region , 1998 .

[36]  Joao M.M. Sousa,et al.  DPIV study of the effect of a gable roof on the flow structure around a surface-mounted cubic obstacle , 2004 .

[37]  R. Pielke,et al.  Infrasound Emitted by Tornado-Like Vortices: Basic Theory and a Numerical Comparison to the Acoustic Radiation of a Single-Cell Thunderstorm , 2008 .

[38]  D. Natarajan.  Numerical Simulation of Tornado-like Vortices , 2011 .

[39]  Hui Hu,et al.  An experimental study of a high-rise building model in tornado-like winds , 2011 .

[40]  Kyung Chun Kim,et al.  Flow structure around a 3-D rectangular prism in a turbulent boundary layer , 2003 .

[41]  Sinisa Krajnovic,et al.  LARGE-EDDY SIMULATION OF THE FLOW AROUND A SURFACE-MOUNTED CUBE USING A DYNAMIC ONE-EQUATION SUBGRID MODEL , 1999 .