Author(s): M. Ben Meftah; F. De Serio; M. Mossa; A. Pollio
Linked Author(s): Michele Mossa, Francesca De Serio
Keywords: Hydraulic jump; Free surface current; Shockwave
Abstract: Experimental data regarding jumps with very high aspect ratios are very rare in literature, therefore experimental works are necessary. The present paper analyses the formation of undular hydraulic jumps in a very large channel, characterized by a 4. 0 m width, for low Reynolds number. Once observed that the investigated jumps were characterized by the formation of lateral shock waves, the purpose of the present work is both to analyse the flow conditions of undular jumps and to verify the experimental validity of the classic shock wave theory in very large channels. Seven experimental tests were carried out and their results can be summarized in the following way: (i) the presence of well developed lateral shock waves similar to those of oblique jumps were observed; (ii) the comparison of the experimental and the theoretical data show that the classical shock wave theory is confirmed, taking into account the experimental errors; (iii) the literature law of the wave height of first wave crest was also confirmed in the case of very large channels.