A method to estimate the planar, instantaneous body force distribution from velocity field measurements

We present a simple method to derive a planar, instantaneous body force distribution from a given two-dimensional velocity field without knowledge of the pressure field, under the specific restriction that the body force is dominated by one component only. Spatial integration then completely recovers this component. Particle image velocimetry and direct numerical simulations of a wall jet induced by a known body force were conducted to validate the method, demonstrating a good agreement of the original and reconstructed force fields.