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

Flow through axial-flow-turbomachinery blading

2018 ◽  
Author(s):  
Marcel Escudier
Keyword(s):  
Flow Velocity ◽  
Compressible Flow ◽  
Dimensional Analysis ◽  
Incompressible Flow ◽  
Compressible Fluid ◽  
Axial Flow ◽  
Linear Cascade ◽  
Dimensional Parameters ◽  
Flow Through

This chapter is concerned primarily with the flow of a compressible fluid through stationary and moving blading, for the most part using the analysis introduced in Chapter 11. The principles of dimensional analysis are applied to determine the appropriate non-dimensional parameters to characterise the performance of a turbomachine. The analysis of incompressible flow through a linear cascade of aerofoil-like blades is followed by the analysis of compressible flow. Velocity triangles for flow relative to blades, and Euler’s turbomachinery equation, are introduced to analyse flow through a rotor. The concepts introduced are applied to the analysis of an axial-turbomachine stage comprising a stator and a rotor, which applies to either a compressor or a turbine.

scholarly journals Measuring thermal conductivity of soils under laboratory conditions.

1969 ◽  
Vol 17 (1) ◽  
pp. 71-79
Author(s):  
A.I. Golovanov
Keyword(s):  
Thermal Conductivity ◽  
Flow Velocity ◽  
Soil Sample ◽  
Water Flow ◽  
Coarse Sand ◽  
Conductivity Measurements ◽  
Soil Layers ◽  
The Real ◽  
Real Flow

Experiments were made to determine the influence of size of soil sample, convection and water flow on the determination of thermal conductivity of soils using a thin needle (0.05 cm radius, 8.5 cm in length) as the heating element and copper cylinders for sample containers. For measurements during a period of 100 seconds the diameter of the sample must be at least 4 cm and to avoid any influence of convection measurements should not exceed 100 seconds. When heating elements are placed horizontally to measure simultaneously the thermal conductivity of different soil layers they should be placed at least 10 cm apart. Thermal conductivity measurements could be used to determine flow velocities of water in coarse sand samples provided that the real flow velocity was highev than 0.35 cm/ min. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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

scholarly journals Normal forces exerted upon a long cylinder oscillating in an axial flow

2014 ◽  
Vol 752 ◽  
pp. 649-669 ◽  
Author(s):  
L. Divaret ◽  
O. Cadot ◽  
P. Moussou ◽  
O. Doaré
Keyword(s):  
Flow Velocity ◽  
Normal Force ◽  
Pressure Coefficient ◽  
Axial Flow ◽  
Fluid Forces ◽  
Normal Forces ◽  
Pressure Distributions ◽  
Damping Rate ◽  
Static Approach ◽  
Yaw Angle

AbstractThis work aims to improve understanding of the damping induced by an axial flow on a rigid cylinder undergoing small lateral oscillations within the framework of the quasistatic assumption. The study focuses on the normal force exerted on the cylinder for a Reynolds number of $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\mathit{Re}=24\, 000$ (based on the cylinder diameter and axial flow velocity). Both dynamic and static approaches are investigated. With the static approach, fluid forces, pressure distributions and velocity fields are measured for different yaw angles and cylinder lengths in a wind tunnel. It is found that for yaw angles smaller than $5{^\circ }$, the normal force varies linearly with the angle and is fully dominated by its lift component. The lift originates from the high pressure coefficient at the front of the cylinder, which is found to depend linearly on the angle, and from a base pressure coefficient that remains close to zero independent of the yaw angle. At the base, a flow deficit and two counter-rotating vortices are observed. A numerical simulation using a $k\mbox{--}\omega $ shear stress transport turbulence model confirms the static experimental results. A dynamic experiment conducted in a water tunnel brings out damping-rate values during free oscillations of the cylinder. As expected from the linear dependence of the normal force on the yaw angle observed with the static approach, the damping rate increases linearly with the axial flow velocity. Satisfactory agreement is found between the two approaches.

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