An optimum velocimetry data display method

This paper proposes a method which determines the optimum grid size for interpolated velocimetry data, without making any priori assumptions about the velocity fields, the system used or analysis method. The method employs condition number as the main criterion for deciding the adequate grid size for a given data set. Data sets displayed accordingly are directly comparable, independently of differing experimental parameters or data processing methods. The discussion is based on computational fluid dynamics (CFD) data of flow past the near wake of a cylinder from which simulated PIV images were generated. These images were analysed with the proposed method and the velocity estimates compared to the CFD data. The method was also applied to a sample PIV image of turbulent flow in a baffled tube. (C) 2000 Elsevier Science Ltd. All rights reserved.