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 [...]
This article is concerned with measuring the dynamic properties of prototype structures, especially those characteristics which are important for calculating structural response to wind loading. Introduction to the Dynamic Characteristics of Prototype Structures: In the design of a tall building or a large bridge, the evaluation of structural response to the design wind load may be important both for serviceability [...]
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 [...]
In this article we will discuss about the developments in the aeroelasticity of bridges. For over 100 years prior to the pivotal Tacoma Narrows bridge disaster of 1940 flexible bridges had been noticeably disturbed and some severely damaged by the wind. However, the late 1930's and early 1940's witnessed introduction of new consciousness and appreciation of what kinds of forces [...]
In a typical city environment where many tall buildings and structures are grouped closely together, the proximity of one building to another can influence the flow field around and the wind forces acting on the buildings. Such interference effects are particularly marked for a group of identical structures such as a line of chimneys. The interactions of neighbouring tall buildings, [...]