Aspects of the use of proper orthogonal decomposition of surface pressure fields

The technique of proper orthogonal decomposition is potentially useful in specifying thernfluctuating surface pressure field around structures. However there has been a degree of controversy overrnwhether or not the calculated modes have physical meanings. This paper addresses this issue throughrnconsideration of the results of full scale experiments, and through an analytical investigation. It is concludedrnthat the lower, most energetic modes are likely to reflect different fluctuating flow mechanisms, althoughrnno mode is likely to be associated with just one flow mechanism or vice versa. The higher, less energeticrnmodes are likely to represent interactions between different flow mechanisms, and to be significantlyrnaffected by the number of measurement points and measurement errors. The paper concludes with a briefrndescription of the application of POD to the problem of building ventilation, and the calculation of claddingrnpressures.