Hydrodynamic characteristics of turbulent flow of an incompressible fluid in a channel with porous walls

1977 ◽  
Vol 32 (4) ◽  
pp. 364-368
Author(s):  
V. V. Dil'man ◽  
L. I. Krupnik ◽  
R. Z. Adinberg
Keyword(s):  
Turbulent Flow ◽  
Incompressible Fluid ◽  
Hydrodynamic Characteristics ◽  
Porous Walls

Calculation of turbulent flow of an incompressible fluid in a circular tube with suction through porous walls

1983 ◽  
Vol 17 (4) ◽  
pp. 559-564 ◽  
Author(s):  
V. M. Eroshenko ◽  
A. V. Ershov ◽  
L. I. Zaichik
Keyword(s):  
Turbulent Flow ◽  
Incompressible Fluid ◽  
Circular Tube ◽  
Porous Walls

scholarly journals HYDRODYNAMICS, DISTRIBUTION OF FLOWS AND THERMAL EFFICIENCY OF COIL HEAT EXCHANGERS IN UNITS OF HEAT-USING APPARATUS OF TUBE FURNACES

2019 ◽  
Vol 62 (4) ◽  
pp. 143-151
Author(s):  
Stanislav P. Sergeev ◽  
Faddey F. Nikiforov ◽  
Sergey V. Afanasiev ◽  
Juliya N. Shevchenko
Keyword(s):  
Heat Exchange ◽  
Turbulent Flow ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Heat Fluxes ◽  
Hydrodynamic Characteristics ◽  
Technological Problem ◽  
Tube Furnaces ◽  
Suction Or Injection ◽  
Coil Heat

The theoretical foundations of construction, mathematical description and engineering calculation of heat exchangers of the serpentine type in blocks of heat-using equipment of tube furnaces and other types of reactors designed for carrying out endothermic reactions (in particular, reforming of natural gas with water vapor) are considered. It is shown that the thermal efficiency of heat exchangers of the coil type is significantly affected by the correct choice of parameters ensuring a uniform distribution of energy flows over the surface of heat-resistant heat exchange tubes. This technological problem is solved by compiling the heat balance and selecting the system of the corresponding equations, which allows to calculate the temperature contour of the coil heat exchanger, its hydrodynamic characteristics and the distribution of mass and heat flows through the heat exchange tubes. The use of the tensor form of the Boussinesq hypothesis is considered, with which the Reynolds equation describing a turbulent flow is transformed to a partial differential equation for a single unknown function and its averaged form is obtained. In relation to the problem under consideration, the correctness of the chosen approach was confirmed both theoretically and experimentally. It is shown that in the core of a turbulent flow with an intense suction or injection, the liquid behaves almost as ideal and the well-known Helmholtz – Friedmann theorem holds with the necessary accuracy. From the aforementioned averaged equation, expressions are obtained that are suitable for describing heat fluxes in channels with suction or injection. According to this theoretical model, thermal calculations of coil-type heat exchangers were carried out, a more accurate assessment of the temperature of the heated medium in each coil tube was made, and the temperature gradient of the external heat carrier over the cross section of the gas duct was found. For the first time in the practice of calculations when choosing the parameters of coils, a number of boundary conditions were taken into account, such as the condition of the coil layout, the necessary heat exchange surface, permissible restrictions on hydraulic resistance, etc.

Connection of the hydrodynamic characteristics of turbulent flow of a liquid with its maximum flow rate

1973 ◽  
Vol 16 (3) ◽  
pp. 466-467
Author(s):  
N. T. Fazullin ◽  
M. S. Fomichev ◽  
A. V. Popov ◽  
A. B. Isaev
Keyword(s):  
Turbulent Flow ◽  
Flow Rate ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Hydrodynamic Characteristics

Paper 6: Turbulent Lubrication Theory Applied to Fluid Film Bearing Design

1969 ◽  
Vol 184 (12) ◽  
pp. 40-47 ◽  
Author(s):  
C. M. Taylor
Keyword(s):  
Turbulent Flow ◽  
Incompressible Fluid ◽  
Thrust Bearing ◽  
Lubrication Theory ◽  
Fluid Film ◽  
Finite Width ◽  
Flow Conditions ◽  
Bearing Design ◽  
Turbulent Flow Conditions

The fluid film bearing designer is encountering situations of turbulent lubrication with ever-increasing regularity. This paper is not concerned with the fundamentals of turbulent lubrication but more with an assessment of the methods available to the bearing designer for the examination of turbulent flow conditions and with the effect of turbulence. The two main ‘engineering’ approaches to turbulence are delineated and their quantitative predictions compared for the case of a finite width plane inclined slider thrust bearing hydrodynamically lubricated with an isoviscous incompressible fluid.

The Special Form of Second Order Accuracy N-S Equations for Incompressible Fluid

2014 ◽  
Vol 644-650 ◽  
pp. 1644-1647
Author(s):  
Zhan Song Li ◽  
Shi Jiang Zhu
Keyword(s):  
Laminar Flow ◽  
Turbulent Flow ◽  
Incompressible Fluid ◽  
Special Form ◽  
Higher Order ◽  
Second Order ◽  
Time And Space ◽  
Order Accuracy ◽  
First Order

Classic N-S equation has first order accuracy in both of time and space. It has only the terms of first order, without the terms of second or higher order. These terms are relative in time and space steps. The time and space steps, as basic elements of fluid research, should be only some finite quantities and not be infinitely near to zero as defined in mathematics. If the terms of second or higher order can be ignored depends on the value of the corresponding derivative multiplied. Compared with terms of first order, the terms of second or higher order can be ignored under the condition of laminar flow. However, under the condition of turbulent flow, these can’t be ignored yet. When turbulent flow develops fully, the terms of first order, compared with terms of second order, can be ignored. So, it is why classic N-S equations aren’t closed when they are used to analyze turbulent flow. On the basic, many different special forms of the second order accuracy N-S equations of incompressible fluid are derived.

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