CHARACTERISTICS OF UNDULAR HYDRAULIC JUMPS: EXPERIMENTAL APPARATUS AND FLOW PATTERNS

In open channel flow, the transition from rapid to tranquil flow is referred to as a hydraulic jump. A hydraulic jump of low height is characterized by free-surface undulations downstream of the jump, and is called an undular jump. In this paper, investigators study undular jumps in an experimental rectangular channel in which the upstream flows are fully developed turbulent shear flows. Through visual and photographic observations, the researchers identify five types of undular jumps and describe the main flow patterns. The presence of lateral shock waves for Froude numbers larger than 1.2 appears to be one of the main flow characteristics. The results indicate that the disappearance of undular jump occurs for Froude numbers ranging from 1.5 to 2.9, and the wavelength and amplitude of free-surface undulations are functions of the upstream Froude number and the aspect ratio of critical depth/channel width. Undular hydraulic jumps can occur aft of ships traveling in canals and shallow waters, coinciding with a rapid increase in ship resistance in these shallow waterways.

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  • English

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  • Accession Number: 00674137
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 14 1995 12:00AM