Flow over a hump: Embedded LES using PANS
In the partially averaged Navier-Stokes (PANS) model and the Partially Integrated Transport Model (PITM), the turbulent viscosity is reduced by decreasing the destruction term in the dissipation (ε) equation which increases ε. This decreases the turbulent viscosity in two ways: first, the turbulent viscosity is reduced because of the enhancement of ε, and, second, the turbulent kinetic energy (k) decreases because of the increased dissipation term, ε.
In Ma etl al (2011), a low-Reynolds number capability is added to the PANS model; the model is applied to channel flow, decaying grid turbulence and the flow over a hill. In Davidson & Peng (2011, 2013) the PANS model is used in embedded LES (channel flow and the flow over a hump). In Davidson (2012) the model is applied to backstep flow and boundary layer flow. In the last paper (Davidson, 2013), the PANS model is used as a zonal LES-RANS model. Near the wall it is used in RANS mode and further away from the wall the model is in LES mode, i.e. in turbulence-resolving mode.
China Agricultural University