Correlations of aerodynamic pressures for prediction of across wind response of structures

Correlation length is one of the four important aerodynamic parameters, which is required for prediction of across-wind response of a structure subjected to vortex shedding. Pressure measurement studies on models of three structures with different plan shapes- a circular, an octagonal and an irregular shape, were conducted under simulated open terrain conditions using the boundary layer wind tunnel. This paper presents experimental details and test results on pressure distributions and measurement of correlation lengths. It is shown that for the circular and octagonal models studied, the modified value of rms lift coefficient, CL,V′ is found to be close to 0.088. Further, for the irregular shaped tower block model also, for the wind angle where the mean across wind force is very small, the value of CL,V′ is found to be around 0.088. Further research is necessary for validating the value of 0.088 for structures with other cross-sectional shapes.