A vortex reactor includes a reactor body having first and second ends, with one or more inlet ports coupled to the first end. The reactor is configured to form one or more vortices in a fluid passed into the reactor. The inlet port(s) may be positioned to advance a reactor fluid into the reactor body at an angle tangential to an inner surface of the reactor body, forming a vortex that advances toward the second end along the inner surface of the reactor body. A vortex induction mechanism can be disposed within the reactor to induce or augment a vortex within the reactor. The reactor includes an ultrasound-imparting device configured to generate cavitation bubbles in the reactor fluid. The fluid flow within the reactor concentrates the cavitation bubbles within the vortex, thereby providing beneficial physical and/or chemical effects, while protecting the reactor walls and other reactor components from cavitational erosion.
