Numerical Analysis of the Fluid Flow Behavior in the Plain Journal Bearing at Textured and Not Textured Surface

Hydrodynamic plain bearings are components that provide the guiding in rotation of rotating machines, such as turbines, the reactors. This equipment works under very severe operating conditions. In order to improve the hydrodynamic performance of these rotating machines, the industrialists specialized in the manufacture of hydrodynamic bearings have designed a bearing model with its textured interior surface. The numerical analysis is carried out to study the for both plain bearings types with a textured a non-textured surface thus to see the improvement of the plain bearing hydrodynamic performances, as well as the fluid flow behavior in motion. The analysis is performed by solving the continuity equation of Navier-Stokes, by the finite volume method, using CFD code. The numerical results show that the most important hydrodynamic characteristics such as pressure, minimal film thickness, friction torque, leakage flow, are significant for the textured plain bearing under rotational velocity of 6000rpm and radial load 10000N compared to obtained for a non-textured plain bearing.

Download Full-text

Turbulent Flow Fluid in the Hydrodynamic Plain Bearing to a Non-Textured and Textured Surface

10.5772/intechopen.94235 ◽

2020 ◽

Author(s):

Bendaoud Nadia ◽

Mehala Kadda

Keyword(s):

Numerical Analysis ◽

Rotational Velocity ◽

Friction Torque ◽

Hydrodynamic Characteristics ◽

Textured Surface ◽

Radial Load ◽

Plain Bearing ◽

Rotating Machines ◽

Turbulent Fluid Flow ◽

Hydrodynamic Bearing

Hydrodynamic bearing are components that provide the guiding in rotation of rotating machines, such as turbines, the reactors. This equipment works under very severe operating conditions: high rotational speed and high radial load. In order to improve the hydrodynamic performance of these rotating machines, the industrialists specialized in the manufacture of hydrodynamic journal bearings, have designed a bearing model with its textured interior surface. The present work is a numerical analysis, carried out to observe the effect of a turbulent fluid flow in a non-textured and textured plain bearing and to thus to see the improvement of the hydrodynamic and tribological performances to a non- textured and textured surface of the plain bearing, under severe operating parameters. The rotational velocity varies from 11,000 to 21,000 rpm and radial load ranging from 2000 N to 9000 N. The numerical analysis is performed by solving the continuity equation of Navier-Stocks, using the finite volume method. The numerical results show that the most important hydrodynamic characteristics such as pressure, flow velocity of the fluid, friction torque, are significant for the textured plain bearing under rotational velocity of 21,000 rpm and radial load 10,000 N compared to obtained for a non-textured plain bearing.

Download Full-text

Numerical simulation and experimental performance research of cylindrical vane pump

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211020037 ◽

2021 ◽

pp. 095440622110200

Author(s):

Yiqi Cheng ◽

Xinhua Wang ◽

Waheed Ur Rehman ◽

Tao Sun ◽

Hasan Shahzad ◽

...

Keyword(s):

Numerical Analysis ◽

Rotational Velocity ◽

Geometric Theory ◽

Mechanical Efficiency ◽

Operating Conditions ◽

Experimental Results ◽

Field Analysis ◽

Total Efficiency ◽

Three Dimensional Model ◽

Vane Pump

This study presents a novel cylindrical vane pump based on the traditional working principle. The efficiency of the cylindrical vane pump was verified by experimental validation and numerical analysis. Numerical analysis, such as kinematics analysis, was performed in Pro/Mechanism and unsteady flow-field analysis was performed using ANSYS FLUENT. The stator surface equations were derived using the geometric theory of the applied spatial triangulation function. A three-dimensional model of the cylindrical vane pump was established with the help of MATLAB and Pro/E. The kinematic analysis helped in developing kinematic equations for cylindrical vane pumps and proved the effectiveness of the structural design. The maximum inaccuracy error of the computational fluid dynamics (CFD) model was 5.7% compared with the experimental results, and the CFD results show that the structure of the pump was reasonable. An experimental test bench was developed, and the results were in excellent agreement with the numerical results of CFD. The experimental results show that the cylindrical vane pump satisfied the three-element design of a positive-displacement pump and the trend of changes in efficiency was the same for all types of efficiency under different operating conditions. Furthermore, the volumetric efficiency presented a nonlinear positive correlation with increased rotational velocity, the mechanical efficiency showed a nonlinear negative correlation, and the total efficiency first increased and then decreased. When the rotational velocity was 1.33[Formula: see text] and the discharge pressure was 0.68[Formula: see text], the total efficiency reached its maximum value.

Download Full-text

A Device for Measuring Thin Fluid Flow Depth Over an Inclined Open Rectangular Channel

Journal of Fluids Engineering ◽

10.1115/1.3153362 ◽

2009 ◽

Vol 131 (10) ◽

Cited By ~ 3

Author(s):

A. K. Majumder

Keyword(s):

Fluid Flow ◽

Flow Behavior ◽

Rectangular Channel ◽

Flow Characteristics ◽

Operating Conditions ◽

Multiple Point ◽

Flow Depth ◽

Flow Rates ◽

Law Of The Wall ◽

Measured Flow

Accurate knowledge of the fluid flow depth over an inclined rectangular open channel is of obvious value in the modeling of flow characteristics over that channel. Understanding of this type of fluid flow behavior is of immense importance to the mineral processing fraternity as a large number of separators work on this principle. Therefore, a multiple point computer-controlled depth gauge was developed to measure water flow depths at various flow rates ranging from 0.81 l/s to 2.26 l/s over an inclined (17.5 deg) rectangular channel (2400 mm long and 370 mm wide). This paper describes the details about the device and the data acquisition procedure. An attempt has also been made to predict the measured flow depths at various operating conditions by using a modified form of the conventional law of the wall model. An overall relative error of 4.23% between the measured and the predicted flow depths at various flow rates establishes the validity of the model.

Download Full-text

Elastic Behavior of the Plain Journal Bearing Coated With a Textured Surface and a Non-Textured Surface

International Journal of Surface Engineering and Interdisciplinary Materials Science ◽

10.4018/ijseims.2020010105 ◽

2020 ◽

Vol 8 (1) ◽

pp. 55-77

Author(s):

Mehala Kadda ◽

Bendaoud Nadia

Keyword(s):

Journal Bearing ◽

Surface Effect ◽

Rotational Velocity ◽

Surface Texturing ◽

Pressure Profile ◽

Operating Conditions ◽

Elastic Behavior ◽

Elastic Behaviour ◽

Shear Stresses ◽

Textured Surface

Surface texturing technology has been newly explored technique in the tribological domain, and this method is carried out to improve the displacement and performance of the Babbitt plain journal bearing with a textured surface. The numerical analysis is carried out to study the textured surface effect on the elastic behaviour of the journal bearing. First, the bearing is tested without texture; second, it is examined completely textured, by varying the operating parameters of the bearing. The performance is observed in a pressure profile, displacement, and shear stress, generated for each combination of radial loads, and rotational velocity of the shaft. The numerical modelling is used by solving the displacement equations by the finite element method to analyses bearing displacement for severe operating conditions. The results show that the elastic deformations for textured bearing, are important and preponderant for higher rotational speeds, and shear stresses are important for higher hydrodynamic pressures.

Download Full-text

Numerical Analysis of the Effect of Misaligned Guide Vanes on Improving S-Shaped Characteristics for a Pump-Turbine

Journal of Fluids Engineering ◽

10.1115/1.4038077 ◽

2017 ◽

Vol 140 (3) ◽

Cited By ~ 4

Author(s):

Xiao Yexiang ◽

Zhu Wei ◽

Wang Zhengwei ◽

Zhang Jin ◽

Ahn Soo-Hwang ◽

...

Keyword(s):

Numerical Analysis ◽

High Speed ◽

Flow Behavior ◽

Internal Flow ◽

Operating Conditions ◽

Guide Vanes ◽

Electrical Grid ◽

Runner Blade ◽

Discharge Rates ◽

Unit Speed

The S-shaped characteristic curves in pump-turbines complicate synchronization with the electrical grid and affect system safety. Misaligned guide vanes (MGVs) are one of the most effective solutions to avoid S-shaped characteristics. The internal flow mechanism with the MGV for improving S-shaped characteristics was studied by numerical analysis. Six operating conditions were modeled in the S-shaped region. Four guide vanes were arranged as the MGVs to qualitatively and quantitatively analyze the flow behavior. The internal flow was quite complex at the four operating points without the MGV; here, the attack angle and the flow behavior had no obvious difference at each vane. For the similar conditions with MGVs, attack angles and internal flow fields varied clearly at each vane, especially in the vaneless region and in the runner blade passages. For the same discharge rates, total openings, and rotating speeds, the internal flows were quite different between with and without the MGVs. The MGVs disrupt the high-speed circumferential water ring (appreciably faster compared to the main flow) in the vaneless region and maintain operation with higher unit speeds. Consequently, the unit speed is larger at the same unit discharge in the S-shaped region. Therefore, the MGV method can reduce S-shaped characteristics.

Download Full-text

PIV-Based Hydrodynamic Analysis of a 2D Lifting Body Using Near-Field Flow Kinematics

10.5957/smc-2021-012 ◽

2021 ◽

Author(s):

Galen W. Ng ◽

Michael J. DeNapoli ◽

Adrian S. Onas

Keyword(s):

Optical Measurement ◽

Measurement Techniques ◽

Operating Conditions ◽

Hydrodynamic Performance ◽

Integral Approach ◽

Hydrodynamic Characteristics ◽

Attractive Alternative ◽

Dynamic Force ◽

Data Set ◽

Force Prediction

The ability to extract quantitative flow information from photographic images of the velocity field using Particle Image Velocimetry (PIV) is a powerful alternative to the more traditional invasive or integrated method techniques. The usage of PIV allows the complete characterization of the flow field, and not just at discrete points. Additionally, with PIV, it is possible to predict the hydrodynamic characteristics of a lifting body without measuring the forces and moments acting upon it. In this paper, the hydrodynamic performance of a NACA 0018 airfoil was determined by analyzing the flow kinematics from a 2D-2C (two-dimensional, two-component) PIV data set. The motivation for this work was to provide a canonical study to show that laser optical measurement techniques such as PIV, can be an attractive alternative to dynamic force testing. The hydrodynamic performance evaluated using PIV data was compared to the computational program XFOIL to assess the validity of the results. The analytical drag force prediction was carried out using the Von Kármán Momentum Integral approach for a flat plate and the Squire-Young boundary layer method as an improved method, whereas the analytical lift force prediction calculation was based on the Kutta-Joukowski theorem. The results show reasonable agreement with the numerical prediction tool XFOIL and they follow the expected trends across all operating conditions. These findings suggest that this methodology might be expanded to conduct hydrodynamic analyses on more complex geometries such as hydrofoils, turbines, propulsors, fin stabilizers, rudders, and other control surfaces using flow kinematics data from PIV.

Download Full-text

Numerical Analysis of Hub Effect on Hydrodynamic Performance of Propellers with Inclusion of PBCF to Equalize the Induced Velocity

Polish Maritime Research ◽

10.2478/v10012-012-0010-x ◽

2012 ◽

Vol 19 (2) ◽

pp. 17-24 ◽

Cited By ~ 3

Author(s):

Hassan Ghassemi ◽

Amin Mardan ◽

Abdollah Ardeshir

Keyword(s):

Numerical Analysis ◽

Velocity Potential ◽

Boundary Integral ◽

The Body ◽

Hydrodynamic Performance ◽

Hydrodynamic Characteristics ◽

Body Effect ◽

Quadrilateral Elements ◽

Induced Velocity ◽

Hub Effect

Numerical Analysis of Hub Effect on Hydrodynamic Performance of Propellers with Inclusion of PBCF to Equalize the Induced Velocity In this article the boundary element method (BEM) is applied to analyze the propeller hub as a non-lifting body and the blades in its vicinity as lifting bodies. In solver, the geometrical modeling of hub, blades are PBCF (Propeller Boss Cap Fin) constructed by quadrilateral elements. The velocity potential is determined on each element by discretized boundary integral equation. Iterative procedure is used to consider the adjacent body effect. In each step the body was independently analyzed with the influence of near body considered in inflow velocity. The induced velocity of propeller was calculated with and without PBCF in downstream. PBCF, an energy-saving device, reduces and uniforms the induced velocity of propeller in downstream. Numerical results of propeller hydrodynamic characteristics including hub effect, induced velocities, PBCF influence are presented.

Download Full-text