INFLUENCE OF FLAT WALL DIFFUSER WALL OSCILLATION ON HYDRODYNAMIC PARAMETERS OF VISCOUS FLUID FLOW

2019 ◽  
Vol 9 (1) ◽  
pp. 119-125
Author(s):  
Evgeny A. KRESTIN
Keyword(s):  
Fluid Flow ◽  
Viscous Fluid ◽  
Stokes Equations ◽  
Hydraulic Drive ◽  
Polar Coordinates ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Viscous Fluid Flow ◽  
Moving Wall ◽  
Hydrodynamic Parameters

In order to reduce the energy consumption, increase the reliability of the hydraulic drive of construction machines and mechanisms, studies of the hydrodynamic parameters of the viscous fluid flow in a flat diffuser during the oscillation of one of the walls of the channel are carried out. Navier-Stokes equations together with the continuity equation are used to construct velocity and pressure fields. The problem is solved in polar coordinates with boundary conditions. The General solution of the problem, which corresponds to the self-similar boundary condition on the moving wall, is obtained. The radial velocity profile has sections of forward and reverse currents and is a standing wave along the angular coordinate. The forces acting on the movable and stationary walls of the diffuser are determined.

scholarly journals A reliable algorithm for time-fractional Navier-Stokes equations via Laplace transform

2019 ◽  
Vol 8 (1) ◽  
pp. 695-701 ◽  
Author(s):  
Amit Prakash ◽  
Doddabhadrappla Gowda Prakasha ◽  
Pundikala Veeresha
Keyword(s):  
Fluid Flow ◽  
Viscous Fluid ◽  
Fractional Derivative ◽  
Series Solution ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Viscous Fluid Flow ◽  
Analysis Scheme ◽  
Homotopy Analysis

Abstract In this paper, numerical solution of fractional order Navier-Stokes equations in unsteady viscous fluid flow is found using q-homotopy analysis transform scheme. Fractional derivative is considered in Caputo sense. The proposed technique is a blend of q-homotopy analysis scheme and transform of Laplace. It executes well in efficiency and provides h-curves that show convergence range of series solution.

One demonstration of the minimum entropy theorem ruling the fluid flow field.

2021 ◽  
Author(s):  
Takashi Hotta
Keyword(s):  
Fluid Flow ◽  
Flow Field ◽  
Viscous Fluid ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Stationary Condition ◽  
Minimum Entropy ◽  
External Energy ◽  
Navier Stokes Equations ◽  
Viscous Fluid Flow

Abstract The minimum entropy theorem of the several fields is well known, but there is no clear review that it shows the possibility of minimum entropy theorem mainly rules the general viscous fluid flow field. In this article, I define appropriately total external energy function and is resolved by variational method, and shows that stationary condition always satisfies the continuity and general Navier-Stokes equations. So on that condition, the minimum entropy theorem could decide directly the general viscous fluid flow field.

scholarly journals Investigation of the Onset of Turbulence in Boundary Layers and the Implications for Solutions of the Navier-Stokes Equations.

2020 ◽  
Author(s):  
Andrew Logan
Keyword(s):  
Boundary Layer ◽  
Fluid Flow ◽  
Flat Plate ◽  
Stokes Equations ◽  
Analytic Solutions ◽  
Navier Stokes ◽  
Pressure Gradients ◽  
Navier Stokes Equations ◽  
Viscous Fluid Flow ◽  
Onset Of Turbulence

This paper investigates the onset of turbulence in incompressible viscous fluid flow over a flat plate by looking at the pressure gradients implied by the Blasius solution for laminar fluid flow and adjusting the predicted flow, leading to a mathematically predictable flow separation in the boundary layer and the onset of turbulence (including both transition and fully turbulent regions - both with and without the presence of a flat plate). It then considers the implications for potential analytic solutions to the Navier-Stokes Equations of the fact that it is possible to predict turbulence and a singularity for many flows (at any velocity).

scholarly journals Research on high-pressure hose with repairing fitting and influence on energy parameter of the hydraulic drive

2021 ◽  
Vol 24 (1) ◽  
pp. 25-32
Author(s):  
Mykola Karpenko ◽  
Olegas Prentkovskis ◽  
Šarūnas Šukevičius
Keyword(s):  
High Pressure ◽  
Fluid Flow ◽  
Stokes Equations ◽  
Hydraulic Drive ◽  
Energy Parameter ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Pressure Drops ◽  
Pressure Losses ◽  
Technical Maintenance

Reliability and maintenance analysis of transport machines hydraulic drives, basically focused to power units: pumps, cylinders etc., without taking in to account junction elements. Therefore, this paper proposes a research analysis on high-pressure hoses and junctions during technical maintenance. Comparative analysis of fluid behavior and energy efficiency inside non-repaired and repaired high-pressure hoses is presented in this research. Theoretical and experimental research results for hydraulic processes inside high-pressure hose is based on the numerical simulations using Navier–Stokes equations and experimental measurement of fluid flow pressure inside high-pressure hoses. Research of fluid flow dynamics in the hydraulic system was made with main assumptions: system flow rate in the range from 5 to 100 l/min, diameter of the hoses and repairing fitting are 3/8". The pressure drops, power losses, flow coefficients at non-repaired and after maintenance hose was obtained as a result. Simulation results were verified by running physical experiments to measure the pressure losses.

scholarly journals INVESTIGATION INTO THE HYDRODYNAMIC PROCESSES OF FITTING CONNECTIONS FOR DETERMINING PRESSURE LOSSES OF TRANSPORT HYDRAULIC DRIVE

Transport ◽  
2020 ◽  
Vol 35 (1) ◽  
pp. 108-120
Author(s):  
Mykola Karpenko ◽  
Marijonas Bogdevičius
Keyword(s):  
Fluid Flow ◽  
Experimental Research ◽  
Stokes Equations ◽  
Hydraulic Drive ◽  
Flow Characteristics ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Pressure Losses ◽  
Physical Experiments ◽  
Hydrodynamic Processes

The article presents the findings of theoretical and experimental research on hydraulic processes occurring in the hydraulic drives of transport machines. The paper analyses the influence of hydrodynamic processes on the flow characteristics of fluid considering different hydraulic fitting connections. The performed analysis is based on numerical simulations using Navier–Stokes equations for the velocity field. The dynamics of fluid flow in the hydraulic system has been investigated taking into account the main parameters like system flow rate in the range of 5 to 100 L/min, the diameter of the pipeline making 1/2” and fitting standards DKOL, ORFS, BSP and JIS. As a result, pressure drop, power losses, resistance and flow coefficients at different fitting connections have been obtained. The article compares the provided results with the findings given employing the calculation method for the standard of equivalent length fitting. To simulate fluid flow, a mesh independence study and turbulence calculations have been performed. Simulation results have been examined conducting physical experiments on measuring pressure losses. Each experimental research includes three measurements of connections bearing in mind each fitting standard.

Fluid flow over and through a regular bundle of rigid fibres

2016 ◽  
Vol 792 ◽  
pp. 5-35 ◽  
Author(s):  
Giuseppe A. Zampogna ◽  
Alessandro Bottaro
Keyword(s):  
Porous Medium ◽  
Fluid Flow ◽  
Flow Field ◽  
Stokes Equations ◽  
Transversely Isotropic ◽  
Navier Stokes ◽  
Leading Order ◽  
Macroscopic Scale ◽  
Navier Stokes Equations ◽  
Homogenized Model

The interaction between a fluid flow and a transversely isotropic porous medium is described. A homogenized model is used to treat the flow field in the porous region, and different interface conditions, needed to match solutions at the boundary between the pure fluid and the porous regions, are evaluated. Two problems in different flow regimes (laminar and turbulent) are considered to validate the system, which includes inertia in the leading-order equations for the permeability tensor through a Oseen approximation. The components of the permeability, which characterize microscopically the porous medium and determine the flow field at the macroscopic scale, are reasonably well estimated by the theory, both in the laminar and the turbulent case. This is demonstrated by comparing the model’s results to both experimental measurements and direct numerical simulations of the Navier–Stokes equations which resolve the flow also through the pores of the medium.

On the energy dissipative spatial discretization of the barotropic quasi-gasdynamic and compressible Navier–Stokes equations in polar coordinates

2018 ◽  
Vol 33 (3) ◽  
pp. 199-210 ◽  
Author(s):  
Alexander Zlotnik
Keyword(s):  
Stokes System ◽  
Stokes Equations ◽  
Physical Property ◽  
Polar Coordinates ◽  
Navier Stokes ◽  
Uniform Mesh ◽  
Viscous Stress ◽  
Spatial Discretization ◽  
Navier Stokes Equations ◽  
Viscous Stress Tensor

Abstract The barotropic quasi-gasdynamic system of equations in polar coordinates is treated. It can be considered a kinetically motivated parabolic regularization of the compressible Navier–Stokes system involving additional 2nd order terms with a regularizing parameter τ > 0. A potential body force is taken into account. The energy equality is proved ensuring that the total energy is non-increasing in time. This is the crucial physical property. The main result is the construction of symmetric spatial discretization on a non-uniform mesh in a ring such that the property is preserved. The unknown density and velocity are defined on the same mesh whereas the mass flux and the viscous stress tensor are defined on the staggered meshes. Additional difficulties in comparison with the Cartesian coordinates are overcome, and a number of novel elements are implemented to this end, in particular, a self-adjoint and positive definite discretization for the Navier–Stokes viscous stress, special discretizations of the pressure gradient and regularizing terms using enthalpy, non-standard mesh averages for various products of functions, etc. The discretization is also well-balanced. The main results are valid for τ = 0 as well, i.e., for the barotropic compressible Navier–Stokes system.

scholarly journals Dynamic analysis of submerged microscale plates: the effects of acoustic radiation and viscous dissipation

2016 ◽  
Vol 472 (2187) ◽  
pp. 20150728 ◽  
Author(s):  
Zhangming Wu ◽  
Xianghong Ma
Keyword(s):  
Viscous Fluid ◽  
Boundary Conditions ◽  
Viscous Dissipation ◽  
Stokes Equations ◽  
Acoustic Radiation ◽  
Navier Stokes ◽  
Rectangular Plates ◽  
Fluid Loading ◽  
Navier Stokes Equations ◽  
Loading Impedance

The aim of this paper is to study the dynamic characteristics of micromechanical rectangular plates used as sensing elements in a viscous compressible fluid. A novel modelling procedure for the plate–fluid interaction problem is developed on the basis of linearized Navier–Stokes equations and no-slip conditions. Analytical expression for the fluid-loading impedance is obtained using a double Fourier transform approach. This modelling work provides us an analytical means to study the effects of inertial loading, acoustic radiation and viscous dissipation of the fluid acting on the vibration of microplates. The numerical simulation is conducted on microplates with different boundary conditions and fluids with different viscosities. The simulation results reveal that the acoustic radiation dominates the damping mechanism of the submerged microplates. It is also proved that microplates offer better sensitivities (Q-factors) than the conventional beam type microcantilevers being mass sensing platforms in a viscous fluid environment. The frequency response features of microplates under highly viscous fluid loading are studied using the present model. The dynamics of the microplates with all edges clamped are less influenced by the highly viscous dissipation of the fluid than the microplates with other types of boundary conditions.

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