Three-Dimensional Laser Anemometer Measurements in an Annular Seal

1991 ◽  
Vol 113 (3) ◽  
pp. 421-427 ◽  
Author(s):  
G. L. Morrison ◽  
M. C. Johnson ◽  
G. B. Tatterson
Keyword(s):  
Reynolds Stress ◽  
Isotropic Turbulence ◽  
Three Dimensional ◽  
Mean Velocity ◽  
Anisotropic Turbulence ◽  
Laser Anemometer ◽  
Annular Seal ◽  
The Mean ◽  
Tensor Distributions ◽  
Anemometer System

The flow field inside an annular seal with a 1.27 mm clearance is investigated using a 3-D laser Doppler anemometer system. Through the use of this system, the mean velocity vector and the entire Reynolds stress tensor distributions are measured for the entire length of the seal (37.3 mm). The seal is operated at a Reynolds number of 18,600 and a Taylor number of 4500. The annular seal is found to produce anisotropic turbulence since the Reynolds stress measurements show the flow entering the seal with isotropic turbulence but exiting the seal with anisotropic turbulence.

3-D Laser Anemometer Measurements in a Labyrinth Seal

1991 ◽  
Vol 113 (1) ◽  
pp. 119-125 ◽  
Author(s):  
G. L. Morrison ◽  
M. C. Johnson ◽  
G. B. Tatterson
Keyword(s):  
Reynolds Stress ◽  
Labyrinth Seal ◽  
Laser Doppler Anemometer ◽  
Recirculation Region ◽  
Mean Velocity ◽  
The Third ◽  
Laser Anemometer ◽  
The Mean ◽  
Tensor Distributions ◽  
Anemometer System

The flow field inside a seven-cavity labyrinth seal with a 0.00127-m clearance was measured using a 3-D laser-Doppler anemometer system. Through the use of this system, the mean velocity vector and the entire Reynolds stress tensor distributions were measured for the first, third, fifth, and seventh cavities of the seal. There was one large recirculation region present in the cavity for the flow condition tested, Re = 28,000 and Ta = 7000. The axial and radial mean velocities as well as all of the Reynolds stress terms became cavity independent by the third cavity. The azimuthal mean velocity varied from cavity to cavity with its magnitude increasing as the flow progressed downstream.

3-D Laser Anemometer Measurements in an Annular Seal

1988 ◽  
Author(s):  
G. L. Morrison ◽  
M. C. Johnson ◽  
G. B. Tatterson
Keyword(s):  
Reynolds Number ◽  
Flow Field ◽  
Velocity Vector ◽  
Laser Doppler Anemometer ◽  
Mean Velocity ◽  
Laser Anemometer ◽  
Annular Seal ◽  
The Mean ◽  
Tensor Distributions ◽  
Anemometer System

The flow field inside an annular seal with a 0.00127 m clearance was measured using a 3-D laser Doppler anemometer system. Through the use of this system, the mean velocity vector and the entire Reynolds stress tensor distributions were measured for the entire length of the seal (0.0373 m). The seal was operated at a Reynolds number of 27,000 and a Taylor number of 6,600.

scholarly journals 3-D Laser Anemometer Measurements in a Labyrinth Seal

1988 ◽  
Author(s):  
G. L. Morrison ◽  
M. C. Johnson ◽  
G. B. Tatterson
Keyword(s):  
Reynolds Stress ◽  
Labyrinth Seal ◽  
Recirculation Region ◽  
Mean Velocity ◽  
The Third ◽  
Laser Anemometer ◽  
The Mean ◽  
Tensor Distributions ◽  
Anemometer System ◽  
Stress Term

The flow field inside a seven cavity labyrinth seal with a 0.00127 m clearance was measured using a 3-D laser doppler anemometer system. Through the use of this system, the mean velocity vector and the entire Reynolds stress tensor distributions were measured for the first, third, fifth, and seventh cavities of the seal. There was one large recirculation region present in the cavity for the flow condition tested, Re = 28,000 and Ta = 7,000. The axial and radial mean velocities as well as all of the Reynolds stress term became cavity independent by the third cavity. The azimuthal mean velocity varied from cavity to cavity with its magnitude increasing as the flow progressed downstream.

Phase-Averaged Wall Shear Stress, Wall Pressure, and Near-Wall Velocity Field Measurements in a Whirling Annular Seal

1996 ◽  
Vol 118 (3) ◽  
pp. 590-597
Author(s):  
G. L. Morrison ◽  
R. B. Winslow ◽  
H. D. Thames
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Three Dimensional ◽  
Field Measurements ◽  
Wall Pressure ◽  
Mean Velocity ◽  
Annular Seal ◽  
Mean Pressure ◽  
Wall Shear ◽  
Anemometer System

The flow field inside a 50 percent eccentric whirling annular seal operating at a Reynolds number of 24,000 and a Taylor number of 6600 has been measured using a three-dimensional laser-Doppler anemometer system. Flush mount pressure and wall shear stress probes have been used to measure the stresses (normal and shear) along the length of the stator. The rotor was mounted eccentrically on the shaft so that the rotor orbit was circular and rotated at the same speed as the shaft (a whirl ratio of 1.0). This paper presents mean pressure, mean wall shear stress magnitude, and mean wall shear stress direction distributions along the length of the seal. Phase-averaged wall pressure and wall shear stress are presented along with phase-averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall, where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure, and wall shear stress are very complex and do not follow simple bulk flow predictions.

scholarly journals Effect of the Flame Dome Depth and Improvement of the Pressure Loss in the Dump Diffuser

1998 ◽  
Author(s):  
Shinji Honami ◽  
Wataru Tsuboi ◽  
Takaaki Shizawa
Keyword(s):  
Velocity Profile ◽  
Reynolds Stress ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Flow Behavior ◽  
Sudden Expansion ◽  
Mean Velocity ◽  
The Mean ◽  
Stress Profiles

This paper presents the effect of flame dome depth on the total pressure performance and flow behavior in a sudden expansion region of the combustor diffuser without flow entering the dome head. The mean velocity and turbulent Reynolds stress profiles in the sudden expansion region were measured by a Laser Doppler Velocitmetry (LDV) system. The experiments show that total pressure loss is increased, when flame dome depth is increased. Installation of an inclined combuster wall in the sudden expansion region is suggested from the viewpoint of a control of the reattaching flow. The inclined combustor wall is found to be effective in improvement of the diffuser performance. Better characteristics of the flow rate distribution into the branched channels are obtained in the inclined wall configuration, even if the distorted velocity profile is provided at the diffuser inlet.

scholarly journals A Novel Simplification of the Reynolds-Chou-Navier-Stokes Turbulence Equations of Incompressible Flow

2018 ◽  
Author(s):  
Bohua Sun
Keyword(s):  
Velocity Field ◽  
Stress Tensor ◽  
Reynolds Stress ◽  
Incompressible Flow ◽  
Velocity Fluctuation ◽  
Explicit Representation ◽  
Navier Stokes ◽  
Mean Velocity ◽  
The Mean ◽  
Turbulence Formulations

Based on author's previous work [Sun, B. The Reynolds Navier-Stokes Turbulence Equations of Incompressible Flow Are Closed Rather Than Unclosed. Preprints 2018, 2018060461 (doi: 10.20944/preprints201806.0461.v1)], this paper proposed an explicit representation of velocity fluctuation and formulated the Reynolds stress tensor in terms of the mean velocity field. The proposed closed Reynolds Navier-Stokes turbulence formulations reveal that the mean vorticity is the key source of producing turbulence.

scholarly journals WKB theory for rapid distortion of inhomogeneous turbulence

1999 ◽  
Vol 390 ◽  
pp. 325-348 ◽  
Author(s):  
S. NAZARENKO ◽  
N. K.-R. KEVLAHAN ◽  
B. DUBRULLE
Keyword(s):  
Large Scale ◽  
Isotropic Turbulence ◽  
Two Dimensional ◽  
Turbulent Spot ◽  
Mean Flow ◽  
Mean Velocity ◽  
Inhomogeneous Turbulence ◽  
Large Scale Vortex ◽  
The Mean ◽  
Mean Strain

A WKB method is used to extend RDT (rapid distortion theory) to initially inhomogeneous turbulence and unsteady mean flows. The WKB equations describe turbulence wavepackets which are transported by the mean velocity and have wavenumbers which evolve due to the mean strain. The turbulence also modifies the mean flow and generates large-scale vorticity via the averaged Reynolds stress tensor. The theory is applied to Taylor's four-roller flow in order to explain the experimentally observed reduction in the mean strain. The strain reduction occurs due to the formation of a large-scale vortex quadrupole structure from the turbulent spot confined by the four rollers. Both turbulence inhomogeneity and three-dimensionality are shown to be important for this effect. If the initially isotropic turbulence is either homogeneous in space or two-dimensional, it has no effect on the large-scale strain. Furthermore, the turbulent kinetic energy is conserved in the two-dimensional case, which has important consequences for the theory of two-dimensional turbulence. The analytical and numerical results presented here are in good qualitative agreement with experiment.

scholarly journals Laser Anemometer Measurements in a Transonic Axial Flow Compressor Rotor

1981 ◽  
Vol 103 (2) ◽  
pp. 430-437 ◽  
Author(s):  
A. J. Strazisar ◽  
J. A. Powell
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Compressor Rotor ◽  
Laser Anemometer ◽  
Flow Phenomena ◽  
Conventional Instrumentation ◽  
Efficient Data ◽  
Shock System ◽  
Flow Compressor ◽  
Anemometer System

A laser anemometer system employing an efficient data acquisition technique has been used to make measurements upstream, within, and downstream of the compressor rotor. A fluorescent dye technique allowed measurements within endwall boundary layers. Adjustable laser beam orientation minimized shadowed regions and enabled radial velocity measurements outside of the blade row. The flow phenomena investigated include flow variations from passage to passage, the rotor shock system, three-dimensional flows in the blade wake, and the development of the outer endwall boundary layer. Laser anemometer measurements are compared to a numerical solution of the streamfunction equations and to measurements made with conventional instrumentation.

Turbulent Vorticity Diffusion in the Stronger Wall Jet Managed by a Flat Plate Wing in the Outer Layer

2015 ◽  
Author(s):  
Takuma Katayama ◽  
Shinsuke Mochizuki
Keyword(s):  
Shear Stress ◽  
Flat Plate ◽  
Outer Layer ◽  
Large Scale ◽  
Reynolds Shear Stress ◽  
Three Dimensional ◽  
Quantitative Relationship ◽  
Wall Jet ◽  
Mean Velocity ◽  
The Mean

The present experiment focuses on the vorticity diffusion in a stronger wall jet managed by a three-dimensional flat plate wing in the outer layer. Measurement of the fluctuating velocities and vorticity correlation has been carried out with 4-wire vorticity probe. The turbulent vorticity diffusion due to the large scale eddies in the outer layer is quantitatively examined by using the 4-wire vorticity probe. Quantitative relationship between vortex structure and Reynolds shear stress is revealed by means of directly measured experimental evidence which explains vorticity diffusion process and influence of the manipulating wing. It is expected that the three-dimensional outer layer manipulator contributes to keep convex profile of the mean velocity, namely, suppression of the turbulent diffusion and entrainment.

Turbulent Statistics of Nearly Isotropic Turbulence Generated by Four Rotating Grids and the Mean Falling Velocity of Particle Through Turbulence

2007 ◽  
Author(s):  
Tatsuo Ushijima ◽  
Osami Kitoh
Keyword(s):  
Isotropic Turbulence ◽  
Terminal Velocity ◽  
Mean Velocity ◽  
Velocity Autocorrelation ◽  
Air Turbulence ◽  
Turbulent Statistics ◽  
Experimental Apparatus ◽  
Particle Property ◽  
The Mean ◽  
Lda Measurement

Box air turbulence is experimentally generated in a rectangular box by using four counter-rotating grids installed inside. Turbulence statistics are obtained from one-point measurement of LDA. Nearly isotropic turbulence with zero-mean velocity is realised in the midst of four rotating grids. The dissipation rate is estimated from the Taylor time microscale of velocity autocorrelation obtained from LDA measurement, since Taylor’s frozen turbulence hypothesis is not applicable. From this estimation, the Reynolds number based on the Taylor length microscale becomes about 200 at maximum in the present experimental apparatus. The mean falling velocity of small particle in turbulent flow is measured in the box turbulence. It is found that the mean falling velocity of the inertia particle could be smaller or larger than the terminal velocity, depending on the particle property, if the ratios of particle response time to turbulence time scale are the same.

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