Granitoid Compositional Zoning by Side-wall Boundary Layer Differentiation: Evidence from the Palisade Crest Intrusive Suite, Central Sierra Nevada, California

1990 ◽  
Vol 31 (3) ◽  
pp. 519-553 ◽  
Author(s):  
W. N. SAWKA ◽  
B. W. CHAPPELL ◽  
R. W. KISTLER
Keyword(s):  
Boundary Layer ◽  
Sierra Nevada ◽  
Side Wall ◽  
Compositional Zoning ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Intrusive Suite

scholarly journals Flat Plate Wing Standing on a Wall Covered with a Thick Boundary Layer. Wing Characteristics under the Effects of Side Wall Boundary Layer and Wing Tip Vortex.

1994 ◽  
Vol 37 (2) ◽  
pp. 355-362 ◽  
Author(s):  
Yoshinori Kita ◽  
Hiroaki Koumoto ◽  
Koji Hirose ◽  
Kyoji Yamamoto
Keyword(s):  
Boundary Layer ◽  
Flat Plate ◽  
Side Wall ◽  
Tip Vortex ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Wing Tip Vortex ◽  
Wing Tip

Fluid motion in a rotating sliced cylinder

1970 ◽  
Vol 68 (1) ◽  
pp. 203-212
Author(s):  
J. A. Durance
Keyword(s):  
Boundary Layer ◽  
Viscous Incompressible Fluid ◽  
Fluid Motion ◽  
Steady Motion ◽  
Side Wall ◽  
Rotating Circular Cylinder ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Interior Flow ◽  
Sloping Bottom

AbstractSteady motion of a viscous incompressible fluid in a rotating circular cylinder with a sloping bottom is investigated at low Ekman number. The flow is driven by a lightly faster rotation of the top, and non-linear inertia terms are neglected.A solution is found for a shallow container of small bottom slope. The side-wall boundary layer is shown to have an almost axi-symmetric component as well as the asymmetric layer found by Pedlosky and Greenspan (3). A further asymmetry in the interior flow is produced by the presence of the second component of the side-wall boundary layer.

Computational modeling of the flow in a wind tunnel

2018 ◽  
Vol 90 (1) ◽  
pp. 175-185 ◽  
Author(s):  
Mahmood Khalid ◽  
Khalid A. Juhany ◽  
Salah Hafez
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Computational Modeling ◽  
Stokes Equations ◽  
Side Wall ◽  
Simultaneous Application ◽  
Content Type ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Solid Walls

Purpose The purpose of this paper is to use a computational technique to simulate the flow in a two-dimensional (2D) wind tunnel where the effect of the solid walls facing the model has been addressed using a porous geometry so that interference arriving at the solid walls are duly damped and a flow suction procedure has been adopted at the side wall to minimize the span-wise effect of the growing side wall boundary layer. Design/methodology/approach A CFD procedure based on discretization of the Navier–Stokes equations has been used to model the flow in a rectangular volume with appropriate treatment for solid walls of the confined volume in which the model is placed. The rectangular volume was configured by stacking O-Grid sections in a span-wise direction using geometric growth from the wall. A porous wall condition has been adapted to counter the wall interference signatures and a separate suction procedure has been implemented for reducing the side wall boundary layer effects. Findings It has been shown that through such corrective measures, the flow in a wind tunnel can be adequately simulated using computational modeling. Computed results were compared against experimental measurements obtained from IAR (Institute for Aerospace, Canada) and NAL (National Aeronautical Laboratory, Japan) to show that indeed appropriate corrective means may be adapted to reduce the interference effects. Research limitations/implications The solutions seemed to converge a lot better using relatively coarser grids which placed the shock locations closer to the experimental values. The finer grids were more stiff to converge and resulted in reversed flow with the two equation k-w model in the region where the intention was to draw out the fluid to thin down the boundary layer. The one equation Spalart–Allmaras model gave better result when porosity and wall suction routines were implemented. Practical implications This method could be used by industry to point check the results against certain demanding flow conditions and then used for more routine parametric studies at other conditions. The method would prove to be efficient and economical during early design stages of a configuration. Originality/value The method makes use of an O-grid to represent the confined test section and its dual treatment of wall interference and blockage effects through simultaneous application of porosity and boundary layer suction is believed to be quite original.

scholarly journals Viscous Flow Field Calculations in High-Loaded Centrifugal Compressor Diffusers

1990 ◽  
Author(s):  
Ingolf Teipel ◽  
Alexander Wiedermann
Keyword(s):  
Boundary Layer ◽  
Turbulent Flow ◽  
Centrifugal Compressor ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Sheet Thickness ◽  
Side Wall ◽  
Flow Fields ◽  
Wall Boundary Layer ◽  
Wall Boundary

The topic of this paper is the computation of transonic turbulent flow fields in high-loaded centrifugal compressor diffusers with a time-marching scheme. A thin-layer approximation is introduced into the time-dependent Navier-Stokes equations and the turbulent quantities are provided by a zero-equation eddy-viscosity model due to Baldwin and Lomax. For solving the governing equations an explicit-implicit MacCormack scheme is applied. The effect of the side wall boundary layer can be employed globally by variable stream sheet thickness. The present code has been verified by comparison of calculated and measured data. Pressure and velocity fields as well as global results like diffuser efficiency have been considered. The code is very efficient at a CRAY-XMP vector computer. Hence, two-dimensional and quasi-three-dimensional turbulent flow fields can be obtained with a reasonable effort. However, one has to be very careful concerning the modelling of the effect of the side-wall boundary layer by variable stream sheet thickness.

Approximate calculation of the wall boundary-layer region for a laminar semiinfinite jet

1976 ◽  
Vol 12 (7) ◽  
pp. 707-711
Author(s):  
A. P. Girol' ◽  
Ya. A. Mikitin
Keyword(s):  
Boundary Layer ◽  
Approximate Calculation ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Boundary Layer Region ◽  
Layer Region

Smooth- and rough-wall boundary layer structure from high spatial range particle image velocimetry

2016 ◽  
Vol 1 (6) ◽  
Author(s):  
D. T. Squire ◽  
C. Morrill-Winter ◽  
N. Hutchins ◽  
I. Marusic ◽  
M. P. Schultz ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Layer Structure ◽  
Rough Wall ◽  
Boundary Layer Structure ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Spatial Range ◽  
Image Velocimetry

Experiments on Flame Flashback in a Quasi-2D Turbulent Wall Boundary Layer for Premixed Methane-Hydrogen-Air Mixtures

2010 ◽  
Author(s):  
Christian Eichler ◽  
Thomas Sattelmayer
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Turbulent Flows ◽  
Turbulent Transport ◽  
Wall Friction ◽  
Evaluation Procedure ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Flame Flashback ◽  
Turbulent Wall

Premixed combustion of hydrogen-rich mixtures involves the risk of flame flashback through wall boundary layers. For laminar flow conditions, the flashback mechanism is well understood and is usually correlated by a critical velocity gradient at the wall. Turbulent transport inside the boundary layer considerably increases the flashback propensity. Only tube burner setups have been investigated in the past and thus turbulent flashback limits were only derived for a fully-developed Blasius wall friction profile. For turbulent flows, details of the flame propagation in proximity to the wall remain unclear. This paper presents results from a new experimental combustion rig, apt for detailed optical investigations of flame flashbacks in a turbulent wall boundary layer developing on a flat plate and being subject to an adjustable pressure gradient. Turbulent flashback limits are derived from the observed flame position inside the measurement section. The fuels investigated cover mixtures of methane, hydrogen and air at various mixing ratios. The associated wall friction distributions are determined by RANS computations of the flow inside the measurement section with fully resolved boundary layers. Consequently, the interaction between flame back pressure and incoming flow is not taken into account explicitly, in accordance with the evaluation procedure used for tube burner experiments. The results are compared to literature values and the critical gradient concept is reviewed in light of the new data.

Sign in / Sign up

Export Citation Format

Share Document