Characteristics of turbulent boundary layer large scale motions using direct fluctuating wall shear stress measurements

Pressure and shear stress measurements at the wall in a turbulent boundary layer on a cylinder

The fluctuating wall shear stress, wall pressure, and streamwise velocity were measured simultaneously in a cylindrical boundary layer at a momentum thickness Reynolds number of Reu52160 and a boundary layer thickness to cylinder radius ratio of d/a55 using a hot wire wall shear stress probe mounted just upstream of a hearing aid microphone and a hot wire velocity probe. Variable Interval Time ...

Near-wall Influence of Large-scale Motions in High Reynolds Number Turbulent Boundary Layers

A spanwise array of surface hot-film shear-stress sensors and a traversing hot-wire located directly above one of these sensors are used to examine the relationship between skin-friction fluctuations and the velocity fluctuations in the boundary layer. Experiments are performed in a high Reynolds number turbulent boundary layer at Reθ ≈ 39000. The shear-stress data indicate the presence of larg...

Relationships between Large-Scale Coherent Motions and Bursting Events in a Turbulent Boundary Layer

Large-eddy simulation of turbulent flow over an array of wall-mounted cubes submerged in an emulated atmospheric boundary-layer

Turbulent flow over an array of wall-mounted cubic obstacles has been numerically investigated using large-eddy simulation. The simulations have been performed using high-performance computations with local cluster systems. The array of cubes are fully submerged in a simulated deep rough-wall atmospheric boundary-layer with high turbulence intensity characteristics of environmental turbulent fl...

Wall shear-stress statistics for the turbulent boundary layer by use of a predictive wall-model with LES

Time-wise velocity signals obtained from large-eddy simulation (LES) within the near-wall, logarithmic region of the zeropressure gradient, flat-plate turbulent boundary layer are used as input to a calibrated, empirical wall model to calculate the statistics of the fluctuating, wall shear stress τw. The results, together with those from numerical simulation and experiment indicate a log-variat...