An experimental study of the primary breakup of a liquid jet in a turbulent low speed crossflow

The effect of turbulence of a low speed crossflow on the primary breakup, trajectory and breakup location of a transversely injected liquid jet was experimentally investigated in this thesis. Turbulent flow field was generated by means of axial fans inside a spherical chamber. Turbulence intensity was varied from 26.21% to 42.11% independently of the mean Weber number and momentum flux ratio using different flow-generating fan configurations. The primary breakup of the liquid jet was examined using two, 1.00 mm and 0.508 mm diameter, nozzles corresponding to an average mean Weber number of 4.479 and 2.266, respectively. the results revealed that an increase in turbulence in the crossflow resulted in an increase in the instantaneous Weber number range, causing multiple breakup regimes to occur, at time simultaneously. For the higher mean Weber number, the breakup regimes shift from bump and arcade breakup being the most common and bag breakup rarely occurring at low turbulence to arcade and bag breakup being the most common at higher turbulence levels. Similar trends were observed at the lower mean Weber number, with the breakup regimes shifting towards higher mean Weber number types of breakup. It was also observed that the transition of arcade breakup to bag breakup occurred around Weg' ~ 5. Images of the trajectory of the liquid jets revealed that there appeared to be a critical point at which the crossflow turbulence began to dominate the behaviour. The crossflow turbulence has little effect prior to this point, beyond which the turbulence causes the jet to bend more into the crossflow, reduces its penetration and causes the jet to fluctuate more. This critical point was found to be strongly dependent on the momentum flux ratio and liquid jet Reynolds number. The normalized breakup height was found to depend on the turbulence intensity and momentum flux ratio, with higher levels of turbulence causing a lower breakup height with the later began to plateau at highe