scholarly journals COUPLING OF TWO UNIFORM FLOWS

2020 ◽  
Vol 8 (4) ◽  
pp. 83-86
Author(s):  
Viktor Kochanenko ◽  
Maria Aleksandrova
Keyword(s):  
Flow Resistance ◽  
Short Length ◽  
Main Task ◽  
Two Dimensional ◽  
Rational Form ◽  
Radial Spreading ◽  
Simple Compression ◽  
Simple Expansion ◽  
Side Walls ◽  
Resistance Forces

The authors consider the problem of coupling two two-dimensional in terms of turbulent potential uniform flows. The flow movement is considered in a smooth horizontal channel with relatively short length of watercourses, when the flow resistance forces can be ignored. The main task is to determine the most rational form of the side walls of the flow interface. Radial spreading of a turbulent flow can be one of the main types of General flows for coupling various forms of flow. First, the flow is transferred through a simple expansion wave to a radial one, then through a simple compression wave it is transferred to a uniform flow. The solution of the problem with this formulation allowed us to improve and update the solution of problems on the coupling of flows.

scholarly journals DETERMINATION OF THE PARAMETERS OF THE LIMITING EXPANSION OF THE FLOW IN THE PROBLEM OF FREE SPREADING OF A TURBULENT FLOW

2021 ◽  
Vol 9 (2) ◽  
pp. 16-20
Author(s):  
Maria Aleksandrova ◽  
Anatoly Kondratenko
Keyword(s):  
Flow Resistance ◽  
Main Task ◽  
Two Dimensional ◽  
Basic Principles ◽  
Friction Forces ◽  
Maximum Expansion ◽  
Side Walls ◽  
Resistance Forces ◽  
Extreme Line

The authors consider the problem of free spreading of two-dimensional, in terms of turbulent, potential uniform flows and obtain an analytical solution. In this case, the flow movement occurs in a smooth horizontal channel along short watercourses, when the flow resistance forces can be neglected. The article approximates the limits of the applicability of the obtained solution. For this purpose, the basic principles of the formation of a flow spreading lobe are considered, taking into account the friction forces. The main task is to determine the extreme line of the current before it hits the side walls and the maximum expansion of the flow, taking into account the resistance forces.

Natural Convection With Non-Newtonian Shear-Thinning Power Law Fluids in Inclined Two Dimensional Rectangular Cavities

2009 ◽  
Author(s):  
Lyes Khezzar ◽  
Dennis Siginer
Keyword(s):  
Natural Convection ◽  
Numerical Experiments ◽  
Newtonian Fluids ◽  
Flow Mode ◽  
Mode Transition ◽  
Two Dimensional ◽  
Power Law Fluids ◽  
Side Walls ◽  
Differential Scheme ◽  
Boussinesq Fluid

Steady two-dimensional natural convection in rectangular cavities has been investigated numerically. The conservation equations of mass, momentum and energy under the assumption of a Newtonian Boussinesq fluid have been solved using the finite volume technique embedded in the Fluent code for a Newtonian (water) and three non Newtonian carbopol fluids. The highly accurate Quick differential scheme was used for discretization. The computations were performed for one Rayleigh number, based on cavity height, of 105 and a Prandtl number of 10 and 700, 6,000 and 1.2×104 for the Newtonian and the three non-Newtonian fluids respectively. In all of the numerical experiments, the channel is heated from below and cooled from the top with insulated side-walls and the inclination angle is varied. The simulations have been carried out for one aspect ratio of 6. Comparison between the Newtonian and the non-Newtonian cases is conducted based on the behaviour of the average Nusselt number with angle of inclination. Both Newtonian and non-Newtonian fluids exhibit similar behavior with a sudden drop around an angle of 50° associated with flow mode transition from multi-cell to single-cell mode.

Approximate and Analytic Solutions for Deformation of Finite Porous Filters

1997 ◽  
Vol 64 (4) ◽  
pp. 929-934 ◽  
Author(s):  
S. I. Barry ◽  
G. N. Mercer ◽  
C. Zoppou
Keyword(s):  
Fluid Flow ◽  
Steady State ◽  
Porous Material ◽  
Deformation Behavior ◽  
Fluid Velocity ◽  
Approximate Solutions ◽  
Analytic Solutions ◽  
Two Dimensional ◽  
Solid Stress ◽  
Side Walls

The deformation, using linear poroelasticity, of a two-dimensional box of porous material due to fluid flow from a line source is considered as a model of certain filtration processes. Analytical solutions for the steady-state displacement, pressure, and fluid velocity are derived when the side walls of the filter have zero solid stress. A numerical solution for the case where the porous material adheres to the side walls is also found. It will be shown, however, that simpler approximate solutions can be derived which predict the majority of the deformation behavior of the filter.

Effect of Inlet Flow Distortion on Performance of Vortex Controlled Diffusers

1992 ◽  
Vol 114 (2) ◽  
pp. 191-197 ◽  
Author(s):  
R. K. Sullerey ◽  
V. Ashok ◽  
K. V. Shantharam
Keyword(s):  
Reynolds Number ◽  
High Pressure ◽  
Velocity Profiles ◽  
Short Length ◽  
Experimental Investigations ◽  
Two Dimensional ◽  
Flow Distortion ◽  
Exit Velocity ◽  
Inlet Velocity ◽  
Vortex Control

The present experimental investigations are concerned with diffusers employing the concept of vortex control to achieve high pressure recovery in a short length. Two types of two-dimensional diffusers have been studied, namely, vortex controlled and hybrid diffusers. Investigations have been carried out on such short diffusers with symmetrically and asymmetrically distorted inlet velocity profiles for area ratios 2.0 and 2.5 and divergence angle of 30 and 45 deg at a Reynolds number of 105. For each of the above configurations, experiments have been carried out for a range of fence subtended angles and bleed rates. The results indicate improvement in diffuser effectiveness up to a particular bleed off for both types of diffusers. It was observed that the nature of exit velocity profiles could be controlled by differential bleed.

The effect of distant side-walls on the evolution and stability of finite-amplitude Rayleigh-Bénard convection

1981 ◽  
Vol 378 (1775) ◽  
pp. 539-566 ◽  
Keyword(s):  
Rayleigh Number ◽  
Prandtl Number ◽  
Finite Amplitude ◽  
Two Dimensional ◽  
Bénard Convection ◽  
Benard Convection ◽  
Side Walls ◽  
Rayleigh Benard Convection ◽  
Rayleigh Numbers ◽  
Rayleigh Benard

A recent study by Cross et al . (1980) has described a class of finite-amplitude phase-winding solutions of the problem of two-dimensional Rayleigh-Bénard convection in a shallow fluid layer of aspect ratio 2 L (≫ 1) confined laterally by rigid side-walls. These solutions arise at Rayleigh numbers R = R 0 + O ( L -1 ) where R 0 is the critical Rayleigh number for the corresponding infinite layer. Nonlinear solutions of constant phase exist for Rayleigh numbers R = R 0 + O ( L -2 ) but of these only the two that bifurcate at the lowest value of R are stable to two-dimensional linearized disturbances in this range (Daniels 1978). In the present paper one set of the class of phase-winding solutions is found to be stable to two-dimensional disturbances. For certain values of the Prandtl number of the fluid and for stress-free horizontal boundaries the results predict that to preserve stability there must be a continual readjustment of the roll pattern as the Rayleigh number is raised, with a corresponding increase in wavelength proportional to R - R 0 . These solutions also exhibit hysteresis as the Rayleigh number is raised and lowered. For other values of the Prandtl number the number of rolls remains unchanged as the Rayleigh number is raised, and the wavelength remains close to its critical value. It is proposed that the complete evolution of the flow pattern from a static state must take place on a number of different time scales of which t = O(( R - R 0 ) -1 ) and t = O(( R - R 0 ) -2 ) are the most significant. When t = O(( R - R 0 ) -1 ) the amplitude of convection rises from zero to its steady-state value, but the final lateral positioning of the rolls is only completed on the much longer time scale t = O(( R - R 0 ) -2 ).

scholarly journals Regular variation and rates of mixing for infinite measure preserving almost Anosov diffeomorphisms

2018 ◽  
Vol 40 (3) ◽  
pp. 663-698 ◽  
Author(s):  
HENK BRUIN ◽  
DALIA TERHESIU
Keyword(s):  
Regular Variation ◽  
Return Time ◽  
Main Task ◽  
Two Dimensional ◽  
Dimensional Torus ◽  
Anosov Diffeomorphisms ◽  
Infinite Measure ◽  
Mixing Rates ◽  
First Return Time ◽  
Almost Anosov

The purpose of this paper is to establish mixing rates for infinite measure preserving almost Anosov diffeomorphisms on the two-dimensional torus. The main task is to establish regular variation of the tails of the first return time to the complement of a neighbourhood of the neutral fixed point.

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