Image measurement of flow field using physics-based dynamic model

The PIV technique is generalized from the viewpoint of the identification p roblem of a flow field. The process of obtaining a velocity distribution as an image measurement can be considered as a parametrization problem of a d ynamical system. In almost all conventional techniques, the velocity is eva luated as the parameters in a dynamical system using a linear model without physics. These methods always give some spurious velocity vectors in the c ase of shear flow or vortex how, and in the region where the tracer particl es are scarce. A new PIV technique based on physics is proposed. The obtain ed velocity field satisfies the governing equation of the fluid. It is poss ible that not only the velocity but also the pressure is measured, using th e Navier-Stokes equations for the dynamic model. The results of jet flow, c avity flow and flow around a waving airfoil demonstrate the effectiveness o f this method.