Abstract
The results of a laboratory investigation on the behaviour of plane turbulent jets discharging vertically upwards into a stagnant shallow water body have shown that for any depth H in terms of the half width b 0 of the nozzle, the jet could be in an oscillating mode if the velocity at the nozzle U 0 is greater than a critical value of [0.009(Hlb 0) + 0.357] √gH where g is the acceleration due to gravity. When the jet is oscillating, the frequency of oscillation ƒ is equal to 0.18 √g/H. An earlier study on vertical circular jets in shallow water did not find such an oscillating flow pattern.