The Flow Over Riblets: Velocity Measurements with Hot-Film Probes

1999 ◽  
pp. 115-120 ◽  
Author(s):  
M. Bruse ◽  
D. W. Bechert ◽  
W. Hage
Keyword(s):  
Velocity Measurements ◽  
Hot Film

The two-sided lid-driven cavity: experiments on stationary and time-dependent flows

2002 ◽  
Vol 450 ◽  
pp. 67-95 ◽  
Author(s):  
CH. BLOHM ◽  
H. C. KUHLMANN
Keyword(s):  
Three Dimensional ◽  
Standing Waves ◽  
Reynolds Numbers ◽  
Time Dependent ◽  
Flow State ◽  
Incompressible Fluid Flow ◽  
Velocity Measurements ◽  
Driven Cavity ◽  
Rectangular Container ◽  
Hot Film

The incompressible fluid flow in a rectangular container driven by two facing sidewalls which move steadily in anti-parallel directions is investigated experimentally for Reynolds numbers up to 1200. The moving sidewalls are realized by two rotating cylinders of large radii tightly closing the cavity. The distance between the moving walls relative to the height of the cavity (aspect ratio) is Γ = 1.96. Laser-Doppler and hot-film techniques are employed to measure steady and time-dependent vortex flows. Beyond a first threshold robust, steady, three-dimensional cells bifurcate supercritically out of the basic flow state. Through a further instability the cellular flow becomes unstable to oscillations in the form of standing waves with the same wavelength as the underlying cellular flow. If both sidewalls move with the same velocity (symmetrical driving), the oscillatory instability is found to be tricritical. The dependence on two sidewall Reynolds numbers of the ranges of existence of steady and oscillatory cellular flows is explored. Flow symmetries and quantitative velocity measurements are presented for representative cases.

scholarly journals Hot-Film Anemometer Velocity Measurements of Arterial Blood Flow in Horses

1974 ◽  
Vol 34 (2) ◽  
pp. 193-203 ◽  
Author(s):  
ROBERT M. NEREM ◽  
JOHN A. RUMBERGER ◽  
DAVID R. GROSS ◽  
ROBERT L. HAMLIN ◽  
GARY L. GEIGER
Keyword(s):  
Blood Flow ◽  
Arterial Blood Flow ◽  
Velocity Measurements ◽  
Arterial Blood ◽  
Hot Film

Hot-wire and hot-film anemometry and conditional measurements: A report on Euromech 132

1981 ◽  
Vol 110 ◽  
pp. 115-128 ◽  
Author(s):  
G. Comte-Bellot ◽  
G. Charnay ◽  
J. Sabot
Keyword(s):  
Fluid Flow ◽  
Hot Wire ◽  
Velocity Measurements ◽  
Complex Flows ◽  
Pattern Recognition Analysis ◽  
Hot Wires ◽  
A New Technique ◽  
Hot Film ◽  
Sampling Pattern ◽  
Hot Film Anemometry

The European Mechanics Colloquium, Euromech 132, was held at the Ecole Centrale de Lyon from 2 to 4 July 1980. Specific areas of hot-wire or hot-film anemometry were presented and discussed, more especially the effect of the finite time constant of the wire supports, the use of yawed hot wires in supersonic flows, the possible improvement of vorticity meters, and multi-point measurements of wall-shear-stress fluctuations. Other subjects described during the meeting included a new technique for concentration measurements in flames, developments and new uses of digitization and conditional sampling, pattern recognition analysis of fluid flow from multi-point, multi-time velocity measurements, and new turbulence measurements in complex flows and in fluid-flow machinery.An exhibition of hot-wire and hot-film anemometers and associated equipment was held during the colloquium.

scholarly journals Measurements of Unsteady Flow Over and Heat Transfer From a Flat Plate

1989 ◽  
Author(s):  
X. Liu ◽  
W. Rodi
Keyword(s):  
Heat Transfer ◽  
Unsteady Flow ◽  
Flat Plate ◽  
Free Stream ◽  
Hot Wire ◽  
Velocity Measurements ◽  
Squirrel Cage ◽  
Plate Velocity ◽  
Flow Processes ◽  
Hot Film

A detailed experimental investigation is described of unsteady flow over and heat transfer from a flat plate. The oncoming 2-D periodic unsteady flow was generated by a squirrel cage device mounted upstream of the plate. Velocity measurements were carried out in the free stream over the plate and in the boundary layer by hot-wire anemometers, and the distributions of pressure and heat transfer coefficient along the plate surface were measured, the latter with a glue-on hot film. All results are presented in ensemble averaged form so that the unsteady flow processes can be studied phase by phase.

3D Structure of the Rotor Wake of a Three Different Sweep Axial Fan

2005 ◽  
Author(s):  
Ge´rald Kergourlay ◽  
Smai¨ne Kouidri ◽  
Gary W. Rankin ◽  
Robert Rey
Keyword(s):  
Experimental Study ◽  
Spectral Analysis ◽  
Data Analysis ◽  
Kinetic Energy ◽  
Stress Tensor ◽  
3D Structure ◽  
Velocity Measurements ◽  
Axial Fan ◽  
Rotor Wake ◽  
Hot Film

This experimental study, applied to a three different sweep axial fan (backward, radial and forward), aims at determining the 3D structure of the rotor wake from unsteady velocity measurements. The hot-film anemometry is used to measure the 3D unsteady velocity components in nearfield, downstream the fan. The data analysis leading to averaged and turbulent velocities, the components of the Reynolds’ stress tensor and the turbulent kinetic energy is presented, in order to illustrate the influence of the sweep. A spectral analysis is also performed.

Propagation of perturbations in the viscous sublayer and adjacent wall region

1979 ◽  
Vol 95 (2) ◽  
pp. 305-322 ◽  
Author(s):  
Hans-Peter Kreplin ◽  
Helmut Eckelmann
Keyword(s):  
Turbulent Channel Flow ◽  
Viscous Sublayer ◽  
Flow Structures ◽  
Wall Region ◽  
Velocity Measurements ◽  
Simultaneous Measurements ◽  
Time Correlations ◽  
Hot Film ◽  
Adjacent Wall ◽  
Streamwise Distance

The fluctuating velocity components, u and w, and their gradients at the wall, \[ (\partial u/\partial y)|_{w}\quad {\rm and}\quad (\partial w/\partial y)|_{w}, \] were measured in a fully developed turbulent channel flow using hot-film probes. The data were taken in an oil channel at a low Reynolds number which allowed velocity measurements very close to the wall. From simultaneous measurements of these signals it could be deduced that coherent flow structures, inclined to the wall, travel downstream. Space-time correlations imply that these are rotating structures. The spanwise distance between these structures was found to be z+ ≈ 50 and they could be observed over a streamwise distance of Δx+ > 1000.

Sign in / Sign up

Export Citation Format

Share Document