Application of Proper Orthogonal Decomposition to Turbulent Channel Flow

Direct numerical simulation (DNS) of a turbulent channel flow at the friction Reynolds number Reτ=180 is carried out. The results of the mean velocity and turbulent kinetic energy are compared to a reference DNS data.An analysis of turbulence is performed using proper orthogonal decomposition (POD), based on the turbulent kinetic energy (TKE). The reconstructed TKE, using various POD modes, shows that 99.9% of the TKE is contained in the first 70 modes. The foot-print of the TKE containing structures, in the near-wall region of the flow, is visualized using reconstructed TKE based on a number of POD modes. Contour plots shows a close correspondence between the reconstructed TKE and DNS data, when more than 7 POD modes are used.It is observed that the difference between the reconstructed TKE and DNS data decreases nonlinearly, with increasing number of POD modes. It is also found that the peak position of the reconstructed TKE and DNS data coincide for any number of POD modes.

کلیدواژه ها:

proper orthogonal decomposition ، direct numerical simulation ، turbulent channel flow ، turbulent kinetic energy