Correction: Statistics and structure of turbulence in fan/FEGV interstage and their aeroacoustic implications

Modern computational capabilities make simulations of complicated flow fields such as those in the fan stage of a turbofan engine possible. In particular, time resolved simulations are presenting new opportunities for studying the disturbances responsible for the broadband noise created by the fan stage. A preliminary quantitative analysis of the simulated flow field in the gap between the fan and fan exit guide vane (FEGV) computed with the Lattice Boltzmann based software PowerFLOW is presented. The study compares the simulated flow with experimental measurements to assess the mean flow, the turbulence intensity, the turbulence length scale and the turbulence dissipation rate. The mean wake is shown to be more diffuse than measured experimentally and the turbulence length scale of the simulated data is 1.5 times greater than that deduced from the measurements while the simulation based dissipation rate is slightly less than the measurement based value. The overprediction of the length scale is shown to potentially have a significant effect on the broadband noise. It is hypothesized that the overprediction is due to the usage of a trip to trigger the turbulent transition on the rotor blade in the computation. This preliminary study provides a path for more detailed wake evolution analysis using the simulation data as well as further flow comparisons for different stage configurations and fan operating speeds.