Experimental Inverstigation On Wind Load Distribution For Interference Of Twin Chimney Stacks

As the landmark building of a large thermal power plant, the chimney has characteristics of large height, small rigidity and large size, etc. These characteristics make it to be sensitive to wind loads. Meanwhile chimneys are usually the dominant factor of investment, design and construction for a thermal power plant. By considering safety and economy, it is necessary to study the effect of wind load on the chimney. Compared with a single chimney, wind loads on two chimneys arranged in some pattern are more complicated due to the possible flow interference of each othetr. It is objective of this thesis to investigate the effect of interference on the distribution characteristics of wind loads.In this paper, through combining with theoretical research and practical experience,simulating real flow of chimney in wind tunnel(boundary layer B).In order to make the test model consistent with the real flow characteristics of the chimney,nominal Renolds number need to be improved through the study of Renolds number effect of drag coefficient method.Through measurement of surface on a single chimney with different surface roughness in boundary layer simulated in the wind tunnel, it is determined that whether the Reynolds number of the flow reaches the supercritical regime.Using the chimney with the specific surface roughness which can ensure the supercritical flow, a series of mutual interference tests of two chimney stacks are conducted. The surface pressure distribution and drag coefficients with different arrangement of chimneys, average center distance between two chimneys L/D, wind direction angle Φ) are obtained by means of pressure measurement.The surface pressure distribution and drag coefficient in different disturbance state are analyzed through the summarizing the theoretical knowledge and calculating the test data methods, and the quantitative relationship of the surface pressure distribution and drag coefficient with L/D and Φ are discussed.Through the analysis of the rules,the influence of distance on interference and critical distance of different arrangement of twin chimney(serial,parallel, diagonal) can be obtained.The results of this study could provide the reference of the wind load determination for the similar projects.