The present paper analyses the advantages and limitations of using numerical modelling to simulate hydraulic jumps at high Froude numbers. Two hydraulic jumps of the same Froude number (7.5) but different Reynolds numbers were simulated using Improved Delayed Detached Eddy Simulation. The free surface was captured using the Volume of Fluid multiphase model with a High-Resolution Interface-Capturing technique. Flow properties including velocity, total pressure and air concentration profiles were compared with experimental results at different streamwise locations. It was observed that while the simulations were able to accurately capture the velocity and pressure fields, the air concentration values were over predicted, although the air concentration distribution was successfully reproduced. Since the simulations capture the complete three-dimensional flow field, further analysis of different physical mechanisms contributing to air entrainment are also carried out. The turbulent kinetic energy and the vorticity field were examined to understand the air–water flow dynamics. The coherent structures responsible for air entrainment were identified using vortex identification techniques. The influence of these structures on the air-entrainment mechanisms is presented with pertinent discussions.