In this article we will discuss about:- 1. Introduction to Wind Loads on Low Buildings 2. Historical Development of Wind Loads on Low Buildings 3. Codes and Standards/Full-Scale Measurements 4. Computational Evaluation of Wind Pressures. Introduction to Wind Loads on Low Buildings: Wind loads on low buildings have not received the attention they deserve when the large investment in such [...]
Regarding wind loading of low buildings the following overall considerations are appropriate: i. Atmospheric simulation requirements are generally similar to those for tall buildings. ii. There is a large variety of low building geometries. iii. Special tests are usually unjustifiable economically and hence there is more reliance on generic tests. iv. Aspects special to low buildings are due to their [...]
In this article we will discuss about:- 1. Introduction to the Physical Modelling of ABL 2. Primary Features of the Atmospheric Boundary Layer (ABL) 3. Similarity Criteria 4. The Meteorological Wind Tunnel (MWT). Introduction to the Physical Modelling of ABL: Efforts to determine wind effects on objects and dispersion of air pollutants using small-scale models in air flows generated by [...]
Comparisons of wind-tunnel and field measurements are essential for checking the validity of modelling criteria and procedures. Micrometeorological data used for the subsequent comparisons are primarily from measurements in the ASL. Stably stratified flow over a smooth surface with only a saw-tooth trip at the test-section entrance was investigated in the MWT by Arya et al (1969). A graph showing [...]
In this article we will discuss about the primary features and historical development of bluff body aerodynamics. Primary Features of Bluff Body Aerodynamics: The term "bluff body aerodynamics" is intended to cover the study of flow fields around, and force on, a body from which boundary layers are separating to form unsteady vortex flows in a wake region. The great [...]
In this article we will discuss about:- 1. Introduction to Strong Winds 2. Historical Perspective of Strong Winds 3. High Wind Speeds 4. Description of the Atmospheric Boundary Layer 5. The Structure of Winds and Its Measurement 6. Description of Statistics 7. Some Significant Measurements 8. Conclusion. Introduction to Strong Winds: The occurrence of strong winds, to their measurement and [...]
In this article we will discuss about how to measure fluctuating pressure caused my wind movements. Pressure Transducers: The basic requirement of a pressure transducer is a device which accurately transforms a pressure difference to an electrical voltage. Two basic phenomena are used: (i) The change in resistance of conducting or semiconducting element as it is strained; and (ii) The [...]
In this article we will discuss about how to estimate extreme wind speeds without regard to direction. To within a constant dimensional factor, the time series Wj is the same as the time series maxi [vJ(θl)] = Vj (j = 1,2, . . ,N). Extreme idealized wind loads can therefore be obtained from estimates of the extreme variate V Inferred [...]
In this article we will discuss about the estimates of various types of wind speeds. Estimates of Extreme Wind Speeds from Short Records: A procedure for estimating extreme wind speeds without regard for direction at locations where long-term data are not available was reported by Simiu et al. (1982) and Grigoriu (1984). The method, whose applicability was tested for 36 [...]
In this article we will discuss about the relation between extreme wind speeds and extreme wind loads. Assume that the wind velocity is known at a particular location and elevation near a structure, where it is unaffected by any obstructions and is therefore indicative of the ambient wind environment. The wind pressure at a point on the building surface, or [...]