viscous sublayer

viscous sublayer

[‚vis·kəs ′səb‚lā·ər]
(fluid mechanics)
In a turbulent flow, a very thin region next to a wall, typically only 1% of the boundary layer thickness, where turbulent mixing is impeded and transport occurs partly or, if the limit as the wall is approached, entirely by viscous diffusion.
References in periodicals archive ?
As seen in Figure 3, the boundary layer can be divided into three regions and they are viscous sublayer, log layer, and defect layer.
The S-shaped curves show that the two SST models consider the viscous sublayer and buffer layer.
The realizable two-layer k - [epsilon] model used in this study combines realizable k - [epsilon] model with two-layer wall modelling approach, which allows the k - [epsilon] model to be applied in the viscous sublayer [14].
For traditional CPB, solid-liquid high-mud SUT is the turbulent viscous sublayer which will produce big resistance loss under the continuous shearing force provided by the pipe wall.
In 2010, Neopane claimed that the k-e model is valid for the free flow region but tends to fail in the viscous sublayer, despite being the most used in the industry due to its stability and numerical robustness.
The control over the entire surfaces to force viscous sublayer resolution was computationally expensive and judged unnecessary.
It can be believed that the upper bound of the viscous sublayer corresponds to the point A, below which the viscous stress is dominant in the total stress.
For the high Prandtl numbers, the grid resolution which captures the viscous sublayer can be inadequate and insufficient for the thermal conduction region.
However, with the roughness reduced on the inner wall, the small convex parts are all completely submerged in the viscous sublayer and the gas pipeline becomes "hydraulic smooth pipe" That means even though the coating surface is smoothed further, the wall friction is difficult to further reduce.
The boundary layers that cover airfoil are divided into viscous sublayer, buffer layer and log-low region (MA, 20009).