A nozzle assembly includes a fluidic oscillator 100 operating on a pressurized fluid to generate an oscillating spray of fluid droplets, and the oscillator aims fluid jets from first, second and third power nozzles 114A, 114B, 114C into an interaction chamber 118 and toward an upwardly projecting island protuberance 126 defining first, second and third island wall segments. The outermost jets 114A, 114B are aimed at an obtuse angle of 100 to 140 degrees along axes which intersect beyond the island at a Jet intersection point, J1. The upstream end of interaction chamber 118 is defined by first and second laterally offset concave wall surfaces 142, 152 which define left side and right side vortex generating areas so that fluid jet steering vortices may be alternately formed and then displaced distally and shed to steer the fluid jet laterally within interaction chamber 118.