Optical fibre probe measurements of bubbly flow in hydraulic jumps

F Murzyn (1) , Dominique Mouazé (2) , J. R. Chaplin (1)

1 University of Southampton
2 M2C - Morphodynamique Continentale et Côtière

This paper describes measurements of void fractions, bubble frequencies and bubble sizes in hydraulic jumps with Froude numbers 2.0, 2.4, 3.7 and 4.8. In each case data were obtained with a dual-tip optical fibre probe at a large number of points throughout the jump. Across the lower part of the flow, dominated by air entrainment into a region of turbulent shear, void fractions follow a Gaussian distribution. In the upper region, dominated by interactions with the free surface, the void fraction follows the form of an error function. The intersection between these two profiles provides a well-defined boundary between the two regions. Comparisons are made with measurements at higher Froude numbers [by Chanson, H., Brattberg, T., 2000. Experimental study of the air–water shear flow in a hydraulic jump. International Journal of Multiphase Flow 26, 583–607] revealing a very large measure of compatibility between the two sets of data.

Mots clés: Hydraulic jump; Two-phase flow; Void fraction; Bubble frequency; Sauter mean diameter; Optical fibre probe; Dual-tip probe

Domaines: Mécanique des fluides [physics.class-ph]

F Murzyn, Dominique Mouazé, J. R. Chaplin. Optical fibre probe measurements of bubbly flow in hydraulic jumps. International Journal of Multiphase Flow, 2005, 31 (1), pp.141--154. ⟨10.1016/j.ijmultiphaseflow.2004.09.004⟩. ⟨hal-01745601⟩