By setting a sinusoidal pulsed flow generator and an air chamber at the head and midst of conduit respectively , and elaborately structuring conditions of water jet system , a strong hydraulic resonance can be induced and pressure amplitude at nozzle can be greatly promoted . The mathematical- physical model of the system is illuminated with characteristics finite difference equations of hydraulic transient and solved by variable time step method . The conditions of desirable resonance are searched by direct search algorithm of Matlab . The sinusoidal pulsed flow generator is composed of a constant discharge pump and a piston cylinder fluctuating sinusoidally in volume . The constant discharge is provided by an electric piston pump driven by cam mechanism , and the sinusoidal volume fluctuation of the cylinder is produced by motion of piston driven by cam or crankshaft mechanism .