THE EFFECT OF DIRECTIONAL VARIATIONS ON THE OBSERVED MEAN AND RMS PRESSURE COEFFICIENTS

A Fourier series is fitted to a set of 10 min mean pressure coefficien t data for the Silsoe Structures Building. Corrections made to this fu nction illustrate the effect of directional variations in rounding the ($) over bar C-p(($) over bar theta) relationship. It is shown that i n a region of local extreme the difference between ($) over bar C-p(($ ) over bar theta) and ($) over bar C-p(theta) may be more than 0.25. T hese series are also used to give an estimate of the contribution to t he fluctuating pressures which results from directional variations. It is shown that this estimate closely matches observed data.