PROPER ORTHOGONAL DECOMPOSITION AND RECONSTRUCTION OF MULTICHANNEL ROOF PRESSURE

The proper orthogonal decomposition (POD) and reconstruction of pressure on the roof of a low-rise building is described. The point pressures acquired simultaneously at 494 taps, uniformly distributed on the building surface, were used in the analysis. The pressure space correlation was computed and employed to calculate the eigenvalues and eigenvectors (modes) for two cases: roof pressure held (RP) and roof and walls pressure (RWP). The first two of the RP modes were found to be respectively similar in shape to the pressure mean square and the mean pressure derivative computed with respect to the wind direction. Strong interaction between the wall and roof pressures was identified from the POD analysis. The POD results for the RP case were employed to reconstruct the point and area-averaged roof pressure. Approximately 30% and 2% of the computed modes were needed to represent the largest negative peak of point and area-averaged roof pressure, respectively. Only one mode was sufficient to reconstruct the mean point and area-averaged roof pressure.