The Interference Effect Of Wind Pressure Distribution And Aerodynamic Force Of Five-pipe Self-supporting Steel Chimney In An X-type Arrangement

Chimneys as towering structures are very common in practical engineering.With the continuous increase in the requirements for smoking emission from chimneys,there are more and more multi-pipe steel chimneys.Because the aerodynamic characteristics of and ?ow around the multi-pipe self-supporting chimneys are different from those of the simple single chimney,it is particularly important to study the interference effects between multi-pipe chimneys.For the X-shaped five-pipe self-standing steel chimney,there is mutual interference among the chimneys under the action of the incoming wind,so that the wind pressure distribution and aerodynamic force are different from the single chimney.Therefore,it is of great significance to study the interference effects of five-pipe self-supporting steel chimneys.This paper taken a domestic 80 m high X-shaped five-pipe self-supporting steel chimney as a research object,and obtains the average and fluctuaing wind pressure on the surface of each chimney of the five-pipe self-supporting steel chimney through a rigid body pressure model wind tunnel test.On this basis,the interference laws of the average wind pressure coefficient,fluctuating wind pressure coefficient and drag coefficient each chimney surface at different measuring point heights,different wind direction angles,and different chimney positions were compared and analyzed.The main work of the thesis are as follows:(1)A pressure measurement test was performed on a single chimney with a changed surface roughness to determine the flow conditions of the chimney at a high Reynolds number.The test conditions of the single chimney were applied to the study of a five-pipe self-standing steel chimney.(2)The interference laws of the average wind pressure coefficient and the fluctuating wind pressure coefficient of the five-pipe self-standing steel chimneys and the five chimneys at different measuring point heights,different chimney positions and different wind direction angles be analyzed in detail.Below the corner,the fluctuating wind pressure coefficients of the upstream leading-edge position of the middle chimney in the middle reaches and the outer side of the downstream chimney showed significant peaks,0.5 and 0.45,respectively.The maximum fluctuating wind pressure coefficient of the five chimneys is 0.6.(3)The interference laws of the average resistance and lift coefficient and fluctuating lift coefficient of the five-pipe self-standing steel chimney and the entire five chimneys at different measuring point heights,different chimney positions,and different wind direction angles were analyzed in detail.The average drag coefficient is the largest at a wind direction angle of 15 ° to 30 °,and the maximum value is 0.73.The average lift coefficient of each chimney is between-0.1 to 0.1.The average lift coefficient of the five chimneys is 0.1.When the overall fluctuating wind pressure coefficient of five chimneys is under the wind direction from 0° to 35°,the lower part of the chimneys shows the maximum and the value is about 0.1.