Leap behavior of ultrasonic standing waves in the liquids

•The paper presents behavior of ultrasonic standing waves in the fluids.•Standing waves can form in a liquid when the distance between the transducer and reflector is not equal to half wavelengths.•Any change of the liquid level leap-changed the standing wave channel height by the multiple of one antinode.•The distance between an ultrasonic emitter and an antinode can be several times smaller than half wavelength of the ultrasound. The generation and behavior of ultrasonic standing waves was modeled using the light cut method for transparent fluid. The oscillations of the fluid surface in initial moment of switching on ultrasound and appearance of standing wave channel were observed. The effect of continuous fluid depth decrease and increase on the behavior of ultrasonic standing wave channel was studied. The ultrasonic standing wave channel floated in the liquid between of the crucible bottom and fluid surface and discretely changed its height by half ultrasonic wavelength with the decrease or increase of the liquid level. This channel had the behavior of a “quasi solid state” and damped of convection.