Investigation of circular jets in shallow water

Abstract

The combined influence of the free surface and the bed on the flow characteristics of circular turbulent jets issued at mid-plane into shallow, stagnant ambient fluid is investigated using a physical model study. A total of nine experiments have been performed under different Reynolds numbers and submergence ratios. The velocity profiles in the horizontal plane are found to be similar, while the velocity profiles in the vertical plane are similar only in the near zone. The growth rate of velocity profiles in the horizontal plane consists of two distinct regions for low submergences, namely regions 1 and 2, corresponding to a mild and steep growth rates, respectively. The growth rate in the vertical plane within the near zone is linear. The local maximum velocity decay rate follows the free circular jet in the near zone and wall or surface jet in the far zone.

Keywords:

• Circular jets
• Horizontal growth
• Shallow water
• Surface interactions
• Vertical growth