This paper is the first half of a two-part publication. In these papers the well-known low Mach number edge tone configuration is investigated which is one of the canonical selfsustained flow configurations leading to simple aeroacoustic flow phenomena. The configuration consist of a planar free jet that impinges on a wedge shaped object. Under certain circumstances the jet starts to oscillate more or less periodically thereby creating an oscillating force on the wedge that acts as a dipole sound source. This first part contains a detailed literature overview and the qualitative discussion of the authors' results of a detailed parametric study. The formulae in the literature describing the dependence of the frequency on exit velocity and nozzle-wedge distance show a broad scatter, although similar in form. In this paper a systematic and thorough study is made by experimental and numerical means and remarkable agreement is found.

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The bifurcation structure of a periodically driven spherical gas/vapour bubble is examined by means of methods of nonlinear analysis. The study of Behnia and his coworkers [1] revealed that the bifurcation structures with the pressure amplitude of the excitation as control parameter are structurally similar provided that R E ω is kept constant. In the present paper, this problem is revisited. Analytical and numerical investigations of the bubble oscillator, which is the Keller-Miksis equation, are presented. It is shown that the validity range of Behnia's condition is governed by the viscosity and the surface tension, and holds only for relatively large bubbles. In water, the effect of viscosity is negligible, and the surface tension plays significant role at bubble size lower than approximately 5 µm.

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In this paper, two scenarios for the formation of shrimp-shaped domains [1] are presented. The employed test model is the Keller-Miksis equation that is a second order, harmonically forced nonlinear oscillator describing the dynamics of a single spherical gas bubble placed in a liquid domain. The results have shown that with an increasing dissipation rate (liquid viscosity), shrimp-shaped domains are evolved within the complex structure of each subharmonic resonances in the amplitude-frequency parameter plane of the external forcing. The mechanism is the coalescence and interaction of two pairs of a period-doubling and a saddle-node codimension-two bifurcation curves.