Diagnostics of turbulent flow parmeters of active mixture in fast axial flow CO 2 laser

2002 ◽  
Author(s):  
S. A. Buyarov ◽  
V. D. Dubrov ◽  
Michail G. Galushkin ◽  
Vladimir S. Golubev ◽  
R. V. Grishayev ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Axial Flow

Turbulent Flow Between Two Disks Contrarotating at Different Speeds

1996 ◽  
Vol 118 (2) ◽  
pp. 408-413 ◽  
Author(s):  
M. Kilic ◽  
X. Gan ◽  
J. M. Owen
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Unsteady Flow ◽  
Turbulent Flow ◽  
Boundary Layers ◽  
Axial Flow ◽  
Radial Component ◽  
Velocity Measurements ◽  
Type Flow ◽  
Radial Outflow

This paper describes a combined computational and experimental study of the turbulent flow between two contrarotating disks for −1 ≤ Γ ≤ 0 and Reφ ≈ 1.2 × 106, where Γ is the ratio of the speed of the slower disk to that of the faster one and Reφ is the rotational Reynolds number. The computations were conducted using an axisymmetric elliptic multigrid solver and a low-Reynolds-number k–ε turbulence model. Velocity measurements were made using LDA at nondimensional radius ratios of 0.6 ≤ x ≤ 0.85. For Γ = 0, the rotor–stator case, Batchelor-type flow occurs: There is radial outflow and inflow in boundary layers on the rotor and stator, respectively, between which is an inviscid rotating core of fluid where the radial component of velocity is zero and there is an axial flow from stator to rotor. For Γ = −1, antisymmetric contrarotating disks, Stewartson-type flow occurs with radial outflow in boundary layers on both disks and inflow in the viscid nonrotating core. At intermediate values of Γ, two cells separated by a streamline that stagnates on the slower disk are formed: Batchelor-type flow and Stewartson-type flow occur radially outward and inward, respectively, of the stagnation streamline. Agreement between the computed and measured velocities is mainly very good, and no evidence was found of nonaxisymmetric or unsteady flow.

The determination of transverse pulsations of turbulent flow velocity in fast-axial flow CO2 laser by phase-conjugation method

2005 ◽  
Author(s):  
S. A. Buyarov ◽  
M. G. Galuskin ◽  
V. D. Dubrov ◽  
V. Y. Panchenko ◽  
Yu. N. Zavalov
Keyword(s):  
Turbulent Flow ◽  
Flow Velocity ◽  
Phase Conjugation ◽  
Axial Flow ◽  
Conjugation Method

BLENDING CHARACTERISTICS OF HIGH-SPEED ROTARY IMPELLERS

2013 ◽  
Vol 34 (4) ◽  
pp. 427-434 ◽  
Author(s):  
Ivan Fořt ◽  
Pavel Seichter ◽  
Luboš Pešl ◽  
František Rieger ◽  
Tomáš Jirout
Keyword(s):  
Turbulent Flow ◽  
Flow Regime ◽  
High Speed ◽  
Large Scale ◽  
Energy Savings ◽  
Axial Flow ◽  
Power Input ◽  
Maximum Energy ◽  
Cylindrical Vessel ◽  
Turbulent Flow Regime

Abstract This paper presents a comparison of the blending efficiency of eight high-speed rotary impellers in a fully baffled cylindrical vessel under the turbulent flow regime of agitated charge. Results of carried out experiments (blending time and impeller power input) confirm that the down pumping axial flow impellers exhibit better blending efficiency than the high-speed rotary impellers with prevailing radial discharge flow. It follows from presented results that, especially for large scale industrial realisations, the axial flow impellers with profiled blades bring maximum energy savings in comparison with the standard impellers with inclined flat blades (pitched blade impellers).

Three-Dimensional Turbulent Flow in the Tip Region of an Axial Compressor Rotor Passage at a Near Stall Condition

2001 ◽  
Author(s):  
Hongwei Ma ◽  
Haokang Jiang
Keyword(s):  
Turbulent Flow ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Leading Edge ◽  
Rotating Stall ◽  
Suction Surface ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Compressor Rotor

This paper presents an experimental study of the three-dimensional turbulent flow field in the tip region of an axial flow compressor rotor passage at a near stall condition. The investigation was conducted in a low-speed large-scale compressor using a 3-component Laser Doppler Velocimetry and a high frequency pressure transducer. The measurement results indicate that a tip leakage vortex is produced very close to the leading edge, and becomes the strongest at about 10% axial chord from the leading edge. Breakdown of the vortex periodically occurs at about 1/3 chord, causing very strong turbulence in the radial direction. Flow separation happens on the tip suction surface at about half chord, prompting the corner vortex migrating toward the pressure side. Tangential migration of the low-energy fluids results in substantial flow blockage and turbulence in the rear of a rotor passage. Unsteady interactions among the tip leakage vortex, the separated vortex and the corner flow should contribute to the inception of the rotating stall in a compressor.

Turbulent Flow Between Two Discs Contra-Rotating at Differential Speeds

1994 ◽  
Author(s):  
Muhsin Kilic ◽  
Xiaopeng Gan ◽  
J. Michael Owen
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Turbulent Flow ◽  
Boundary Layers ◽  
Axial Flow ◽  
Radial Component ◽  
Velocity Measurements ◽  
Rotating Discs ◽  
Type Flow ◽  
Radial Outflow

This paper describes a combined computational and experimental study of the turbulent flow between two contra-rotating discs for −1 ≤ Γ ≤ 0 and Reφ ≃ 1.2 × 106, where Γ is the ratio of the speed of the slower disc to that of the faster one and Reφ is the rotational Reynolds number. The computations were conducted using an axisymmetric elliptic multigrid solver and a low-Reynolds-number k-ε turbulence model. Velocity measurements were made using LDA at nondimensional radius ratios of 0.6 ≤ x ≤ 0.85. For Γ = 0, the rotor-stator case, Batchelor-type flow occurs: there is radial outflow and inflow in boundary layers on the rotor and stator, respectively, between which is an inviscid rotating core of fluid where the radial component of velocity is zero and there is an axial flow from stator to rotor. For Γ = −1, anti-symmetrical contra-rotating discs, Stewartson-type flow occurs with radial outflow in boundary layers on both discs and inflow in the viscid nonrotating core. At intermediate values of Γ, two cells separated by a streamline that stagnates on the slower disc are formed: Batchelor-type flow and Stewartson-type flow occur radially outward and inward, respectively, of the stagnation streamline. Agreement between the computed and measured velocities is mainly very good, and no evidence was found of nonaxisymmetric or unsteady flow.

The Numerical Prediction of Turbulent Flow and Heat Transfer in The Entrance Region of a Parallel Plate Duct

1976 ◽  
Vol 98 (4) ◽  
pp. 594-600 ◽  
Author(s):  
A. F. Emery ◽  
F. B. Gessner
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Axial Flow ◽  
Entrance Region ◽  
Parallel Plates ◽  
Fully Developed Flow ◽  
Flow And Heat Transfer ◽  
Corner Flows

Velocity and temperature profiles were computed for turbulent flow, both in the entrance region and the fully developed state, in a duct with heated parallel plates. By starting the calculations at the duct inlet and using a finite difference technique and a three-dimensional mixing length originally defined for corner flows, it was possible to predict axial flow behavior and the nonasymptotic approach to fully developed flow with and without associated heat transfer.

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