  Numerical simulation of high-speed turbulent water jets in air and its
validation with experimental data has not been reported in the literature. It
is therefore aimed to simulate the physics of these high-speed water jets and
compare the results with the existing experimental works. High-speed water jets
diffuse in the surrounding atmosphere by the processes of mass and momentum
transfer. Air is entrained into the jet stream and the entire process
contributes to jet spreading and subsequent pressure decay. Hence the physical
problem is in the category of multiphase flows, for which mass and momentum
transfer is to be determined to simulate the problem. Using the Eulerian
multiphase and the k-\epsilon turbulence models, plus a novel numerical model
for mass and momentum transfer, the simulation was achieved. The results
reasonably predict the flow physics of high-speed water jets in air.
