Abstract
In recent works, the authors have reported an extension of PIV, called "Interface Gradiometry" (PIV/IG) that, by shearing templates to various degrees, directly measures the instantaneous velocity gradient at a fixed wall. This approach works well when the height of templates is carefully chosen. Our recent generalization of the original PIV/IG (denoted PIV/IG+; Nguyen & Wells 2006), does not require a template height to be specified a priori for pattern matching, and is thus more widely applicable. It also introduces an image transformation to handle curved boundaries. The present communication considers the sensitivity of PIV/IG+ results to errors in estimated wall position.
