A digital mask technique for reducing the bias error of the correlation-based PIV interrogation algorithm

In this paper the bias phenomenon in the evaluation of PIV recordings by us ing the correlation-based interrogation algorithm is discussed, and a digit al mask technique, that can effectively reduce the bias error, is introduce d. The correlation-based interrogation algorithm, when masked with a Gaussi an window function, can achieve a higher evaluation accuracy not only for P IV recordings of flows with small velocity gradients, but also for that of flows with large gradients.