A computational analysis using standard k-epsilon model, RSM and LES has been carried out for jet loop reactors (JLR) to investigate the mean and turbulence quantities. These simulations have revealed that the flow in JLR was different from the self-similar round jets. RSM and LES showed better agreement with PIV measurements compared with standard k-epsilon model. The modeled turbulence production and transport in k-epsilon model overpredicted those estimated from LES data. To reduce the limitations, modified k-epsilon models have been evaluated for JLR. Also, a hybrid k-epsilon model has been suggested, which was found to perform better than other modified k-epsilon models. This model was also found to hold for stirred tank reactors (STRs). Mixing time analysis has been carried out for JLR and STR at same power consumption. It has been shown that JLR can be inferior to STR if proper nozzle diameter is not selected. (C) 2009 American Institute of Chemical Engineers AIChE J, 55: 2526-2544, 2009