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Showing 1 to 10 of 10 for “"wall similarity"”.
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Near-wall similarity in three-dimensional turbulent boundary layers
This work investigates three main topics. The first of these is the development and comparison of time integration schemes on two-dimensional unstructured meshes. Both explicit and implicit solution algorithms for the two-dimensional Euler equations on unstructured grids are presented. …
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Near-wall similarity in two- and three-dimensional turbulent boundary layers
Static pressure, mean velocity, indirect wall shear from Preston tubes, direct wall shear using a two-dimensional (single line of action) floating element device, and direct wall shear measurements from an omnidirectional floating element capable of simultaneously determining magnitude and …
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A numerical analysis of turbulent flow along an abruptly rotated cylinder
… It is these correlations (particularly near-wall similarity or the law-of-the-wall) which serve as the empirical foundation of the mixing length and eddy viscosity "theories" of turbulence. The term mathematical model may more aptly describe the mixing length/eddy viscosity approach to …
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Roughness Effects on Super Structures in Turbulent Boundary Layer Flows
This study investigates the influence of wall roughness on large-scale structures within turbulent boundary layers, using wall-parallel stereoscopic Particle Image Velocimetry (PIV) at a Reynolds number of 1.3 × 106m−1. The data was collected at a distance of = 2.8 from the wall under adverse = …
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Near-wall velocity measurements in two-dimensional turbulent boundary layers
Significant differences involving near-wall velocity profiles in two-dimensional turbulent boundary layers when such data was plotted on law of the wall coordinates were reported by D. Coles in the Stanford Conference. These discrepancies can be especially important when near-wall velocity data is …
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Open-Channel Flow With Roughness Elements of Different Spanwise Aspect Ratios: Turbulence Structure and Numerical Modeling
Under rough-wall conditions the length scales governing the flow dynamics in the inner region of boundary layers are no longer determined by the flow itself (i.e. $\nu$/$u\sb*$ for smooth walls), but rather independently specified by the real dimensions of the elements. In particular, the ratio …
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The Resolution and Structure of High Reynolds Number Turbulent Boundary Layers Over Rough and Smooth Walls in Pressure Gradient
… fields of high Reynolds number, turbulent, wall boundary layers in non-equilibrium pressure gradients are experimentally investigated. Experiments in two wall configurations were performed; one with a hydrodynamically smooth test wall composed of flat aluminum panels, and the other with a …
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Effects of boundary roughness on turbulence in uniform open channel flow
… measurements were possible not only in the near wall region but also within the viscous sublayer. Using the data from both the log law and linear viscous sublayer fits allowed for more reliable computations of shear stresses as well as a better understanding of how turbulence behaves over the …
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Effects of surface roughness on the flow characteristics in a turbulent boundary layer
… boundary layers on aerodynamically smooth walls has been clarified over the last decade or so. However, the dynamics of turbulent boundary layers over rough surfaces is much less well known. Nevertheless, there are many industrial and environmental flow applications that require …
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Experimental study of low-order models of highly-irregular roughness and their impact on turbulent boundary layers
… instantaneous velocity fields in the streamwise–wall-normal plane for developing- and developed-flow conditions at moderate Reynolds number followed by stereo PIV measurements in a wall-parallel plane deep in the roughness sublayer (y = 0.047δ). Comparison of both single- and multipoint …