Several practical applications call for a better understanding of the flow phenomena around structures to assess wind loads and wind induced behaviour of structures, when they are located in isolation or in a group. These include structures surrounded by other structures, viz. tall chimneys, cooling towers,other surrounding power plant structures, etc. The responses of these structures to wind in their real environments can be considerably different from those measured/evaluated in the isolated condition. Neighbouring structures may either decrease or increase the wind-induced forces on a structure, commonly called as interference effects, and mainly depend on the geometry, spacing, type of arrangement (tandem or staggered), angle of wind incidence, on-coming turbulence due to upstream terrain conditions, etc. Proper assessment of the interference effects is very important for the design of wind sensitive structures. The existing provisions in various codes of practices on wind effects on structures offer limited guidance to the designer, in assessing the effects of interference.
Hence many wind tunnel investigations have been carried out to evaluate the interference effects on industrial tall RC Chimneys, Cooling towers etc., due to similar structures or other surrounding structures. The following are some of the outcomes from these investigations:
- Guidelines to estimate the interference factors between tall RC chimneys arranged in tandem configuration.
- Guidelines to estimate the interference factorsfor tall RC chimneys surrounded by power plant structures.
- Guidelines on aerodynamic coefficients and interference factors for cooling towers
- Studies on effectiveness of strakes on Chimney both in isolated and grouped conditions
- Studies on effectiveness of ribs on cooling towers