Contact:
Dr. Hasan U. Akay, Director of MURI, Email: hakay@iupui.edu, Ph: (317) 274-9712
 
Wind Effect on Urban Structures
Project:
“Extreme Wind and Air Pollution Simulation of Indianapolis Downtown,”
: Dr. Erdal Yilmaz (ME), Co-Mentor: Dr. Hasan U. Akay (ME), 
Students: Braden Duffin (ME), Adam Campbell (GEOG),  
Duration: August 2006-August 2007  

More on this research:  
Poster#1: Poster presentation on the extreme wind effect presented in Indiana GIS Conference in March’07    
Presentation#1: Presentation in MURI Workshop in April’07   
Presentation#2: Presentation in Indiana GIS Conference in March’07  

Motivations: 
In April of 2006, Indiana was challenged with some of the most extreme and violent storm conditions on record.  One particular storm brought winds sufficient to cause severe damage in the downtown Indianapolis area.  In particular, shattered windows and structural damage occurred on three faces of One Indiana (or Region’s Bank) tower.  The nature of the damage prompted some debate about whether the damage was caused by a tornado or extreme straight wind conditions.  After close examination the National Weather Service concluded that the damage was actually caused by straight wind conditions.  This incident raises several questions:  What wind conditions are sufficient to cause such structural damage in a high-rise building?  Could other buildings in downtown Indianapolis be in danger?  How can city planners predict or avoid such circumstances in the future?   

Methodology: 
These questions and concerns can be answered with the help of Computational Fluid Dynamics (CFD) analyses.  The characteristics and properties of a fluid flow such as wind conditions through city canyons are highly dependent on geometric structures within the flow domain.  Correspondingly, straight wind gusts through downtown Indianapolis result in very turbulent and swirling flows.  A CFD analysis of the conditions surrounding the One Indiana tower building during the violent storm will reveal local pressure forces and wind velocities.     
    CFD is a method for predicting and analyzing fluid flow situations.  CFD incorporates numerical methods to solve fundamental fluid dynamics equations at various locations for a particular geometry.  A three dimensional computer model is created to represent the physical geometry of the problem.  A grid is created that relates specific points within the flow domain to a standard coordinate system.  A computer is used to iteratively solve fundamental fluid dynamics equations at each grid point based on certain already known flow characteristics.  An accurate solution will reveal fine details of the flow such as pressure and velocities at every point in the grid.       
    The commercial CFD code Fluent (www.fluent.com) was used to produce the flow solutions, and the Fluent pre-processing program Gambit was used to create building geometries and grids from CAD model of the city.  Fluent is a powerful CFD solution algorithm that is used widely for industrial purposes.     
    To successfully create a model and then accurately perform the simulations, several supporting background research need to be done: using LiDAR data for 3D representation of the buildings, creating thermal image of the downtown, gathering wind and air pollution data, and finally mapping the facilities that that emits pollutants in the area.  

Acknowledgment:  
This study is supported by Multidisciplinary Undergraduate Research Institute (MURI) in IUPUI.  WInd_Effect_files/ExtremeWind_Poster_INGIS2007.jpgWInd_Effect_files/ExtremeWind_AIrQUality_April07_MURI_Workshop-1.pdfWInd_Effect_files/ExtremeWind_AIrQuality_INGIS07_Workshop-1.pdfhttp://www.fluent.comhttp://www.muri.iupui.edu/shapeimage_3_link_0shapeimage_3_link_1shapeimage_3_link_2shapeimage_3_link_3shapeimage_3_link_4