Author(s): Wangru Wei, Jun Deng
Linked Author(s): Wangru Wei
Keywords: Impinging jet, velocity, turbulence, water depth, numerical simulation study
Abstract: The objective of this study is to investigate turbulent characteristics of two-dimension impinging jet for different water depth. Numerical simulations of turbulent impinging jet are performed based on a standard k-? turbulent model. It is found that jet core length does not change for different water depth, while the mean centerline velocity along relative flow direction decays faster in both established region and impact region for deeper water depth, and development of jet entrainment improves in deeper water depth. At a certain transverse section in established region, mean turbulent kinetic energy grows from centerline, reaches a peak, and then gradually falls. This process gets smoother and the distance between centerline and peak gets greater at the transverse direction as jet develops downstream in established region, which is much more notable in deeper water depth. In development region, mean turbulent kinetic energy decreases along the flow direction due to the sudden transition of boundary conditions, and the trends are not affected by water depth. In established region, mean turbulent kinetic energy increases rapidly with flow distance, reaches peak and then falls gradually until the end of this region. In jet impact region, mean turbulent kinetic energy rises steeply and drops sharply in the near-wall region. This is because the streamline direction of impinging jet changes drastically in this region. For deeper water depth, the variation range of mean turbulent kinetic energy in established region is larger, while in jet impact region near wall, mean turbulent kinetic energy changes much more drastically in shallow water
Year: 2017