Doppler effect in the ripple tank: further experiments with a moving source

Abstract

In this paper, we extend some recent works about the Doppler effect in surface waves on water. We improve the experimental set up by exploring several situations: source in motion with constant velocity and receiver at rest, source at rest and receiver in motion with constant velocity, as well as both source and receiver in motion. Thereby we produce fractional frequency changes Δ f / f 0 of the order of 40%-50%, far larger than those obtained by more traditional sound experiments. The experimental setup, the data collection and the data analysis also allow to highlight some aspects relevant from a didactic point of view, in particular, the experimental results clearly show the nonlinearity of the Doppler shift with the moving source velocity.