Improve Journal Bearing Design Using Numerical Method

2011 ◽  
Vol 99-100 ◽  
pp. 857-861
Author(s):  
Neng Jun Jiang ◽  
Ya Ling Peng ◽  
Fang Liang Wu
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Numerical Method ◽  
Journal Bearing ◽  
Good Match ◽  
Force Direction ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Bearing Design

Computational Fluid Dynamics (CFD) was used to study the force direction and magnitude of 2D journal bearing and tapered gap, also the load of 3D journal bearing at different eccentric ratio was studied using numerical method. All numerical simulation results were compared with theoretical analysis result, theoretical solution result and other available data from reference. The comparisons show good match between numerical simulation results and others. This paper had validated the reliability and accuracy of CFD which could be used to study the lubrication and oil film status for journal bearing with the gap less than 0.2mm and provide a sold foundation for CFD to be used for optimal design for journal bearing.

Numerical and Experimental Study on a Honeycomb Ceramic Monolith

2012 ◽  
Vol 532-533 ◽  
pp. 431-435
Author(s):  
Chong Zhi Mao ◽  
Qian Jian Guo ◽  
Lei He
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Computational Fluid Dynamics ◽  
Flue Gas ◽  
Regenerative Process ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Honeycomb Ceramic ◽  
Oxidation Reactor

Honeycomb ceramic is the key component of the regenerative system. The numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the test data. The regenerative process of a honeycomb ceramic regenerator was simulated under different conditions. Experiments were carried out on honeycomb regenerators that are contained in a methane oxidation reactor. The calculated temperatures of flue gas inlet were compared with the ones measured. The tendency of the temperature is the same as the experiment.

Numerical Simulation of Cross-Ventilation in Buildings Affected by Surrounding Buildings with Different Separation Distances

2013 ◽  
Vol 353-356 ◽  
pp. 2993-2996 ◽  
Author(s):  
Tao Tao Shui ◽  
Jing Liu ◽  
Fei Ma
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Street Canyon ◽  
Natural Ventilation ◽  
Flow Characteristics ◽  
Airflow Rate ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Des Model

In order to investigate natural cross-ventilation in buildings, computational fluid dynamics (CFD) with the DES model is applied. The aim of this paper is to investigate the influence of surrounding buildings on natural ventilation in target building under different separation distances. The simulation results indicate that surrounding buildings has a significant impact on airflow structure and airflow rate of the target building. The flow characteristics in target building is determined by the flow regime in street canyon.

scholarly journals Journal Bearing: An Integrated CFD-Analytical Approach for the Estimation of the Trajectory and Equilibrium Position

2020 ◽  
Vol 10 (23) ◽  
pp. 8573
Author(s):  
Franco Concli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Distribution ◽  
Equilibrium Position ◽  
Analytical Approach ◽  
Journal Bearing ◽  
Cfd Model ◽  
Cavitation Model ◽  
Computational Fluid Dynamics Cfd ◽  
The Mathematical Model

For decades, journal bearings have been designed based on the half-Sommerfeld equations. The semi-analytical solution of the conservation equations for mass and momentum leads to the pressure distribution along the journal. However, this approach admits negative values for the pressure, phenomenon without experimental evidence. To overcome this, negative values of the pressure are artificially substituted with the vaporization pressure. This hypothesis leads to reasonable results, even if for a deeper understanding of the physics behind the lubrication and the supporting effects, cavitation should be considered and included in the mathematical model. In a previous paper, the author has already shown the capability of computational fluid dynamics to accurately reproduce the experimental evidences including the Kunz cavitation model in the calculations. The computational fluid dynamics (CFD) results were compared in terms of pressure distribution with experimental data coming from different configurations. The CFD model was coupled with an analytical approach in order to calculate the equilibrium position and the trajectory of the journal. Specifically, the approach was used to study a bearing that was designed to operate within tight tolerances and speeds up to almost 30,000 rpm for operation in a gearbox.

Optimal Hardware Placement in a Minitower Computer Enclosure System

2011 ◽  
Author(s):  
M. Alfaro Cano ◽  
A. Hernandez-Guerrero ◽  
C. Rubio Arana ◽  
Aristotel Popescu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Operating Temperature ◽  
Optimal Placement ◽  
Cfd Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
The Relationship ◽  
Key Questions

One of the requirements for existing personal computers, PCs, is that the hardware inside must maintain an operating temperature as low as possible. One way to achieve that is to place the hardware components at locations with enough airflow around it. However, the relationship between the airflow and temperature of the components is unknown before they are placed at specific locations inside a PC. In this work a Computational Fluid Dynamics (CFD) analysis is coupled to a Design of Experiment (DOE) methodology to answer typical minitower key questions: a) how do the possible positions of hardware components affect their temperature?, and b) is it possible to get an optimal placement for these hardware components using the data collected by the CFD simulation results? The DOE methodology is used to optimize the analysis for a very large number of possible configurations. The results help in identifying where the efforts need to be placed in order to optimize the positioning of the hardware components for similar configurations at the designing stage. Somehow the results show that general conclusions could be drawn, but that there are not specific rules that could be applied to every configuration.

Experimental and numerical study of vortex gripper with a diversion body

2011 ◽  
Vol 226 (6) ◽  
pp. 1526-1534 ◽  
Author(s):  
Q Wu ◽  
Q Ye ◽  
G X Meng
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Swirling Flow ◽  
Numerical Study ◽  
Reynolds Stress Model ◽  
Stress Model ◽  
Lifting Force ◽  
Handling Device ◽  
Simulation Results

This article introduces a new vortex gripper with a diversion body. Vortex gripper, as a pneumatic non-contact handling device, can generate lifting force to hold a workpiece without any contact. In order to predict the characteristics of this new vortex gripper, including pressure distribution on the upper surface of the workpiece, lifting force, supporting stiffness, and flowrate, a computational fluid dynamics study has been carried out. In the vortex cup, air swirling flow is a complex turbulent one; so Reynolds stress model (RSM) was used to describe internal air swirling flow. In addition, an experiment was carried out to study the characteristics of the vortex gripper. When compared with the experimental results, the reliability of numerical simulation results by RSM was verified. The vortex gripper with a diversion body could generate greater lifting force when compared with those designed by Xin et al. with the same air consumption. Therefore, the efficiency of the vortex gripper is improved.

COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF FABRICATED MICRONOZZLE FOR SUPERSONIC PARTICLE DEPOSITION

2010 ◽  
Vol 17 (01) ◽  
pp. 45-49
Author(s):  
KYUBONG JUNG ◽  
WOOJIN SONG ◽  
DOO-MAN CHUN ◽  
JUN-CHEOL YEO ◽  
MIN-SAENG KIM ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particle Deposition ◽  
Room Temperature ◽  
Flow Analysis ◽  
Dynamics Analysis ◽  
Nanoparticle Deposition ◽  
Computational Fluid Dynamics Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results

A micronozzle was applied in nanoparticle deposition system (NPDS) for supersonic deposition. To determine whether suitable behavior of supersonic fluid can be produced or not, computational fluid dynamics (CFD) flow analysis was used. Ni particles were successfully deposited using the fabricated micronozzle in NPDS at room temperature. It was found that shorter micronozzle with larger side profile deposits wide and thick film compared to the deposition using long micronozzle with smaller side profile. These experimental results agree with the simulation results.

scholarly journals Numerical Simulation of Single-Phase and Two-Phase Flows in Separator Vessels with Inclined Half-Pipe Inlet Device Applied in Reciprocating Compressors

2018 ◽  
Vol 8 (3) ◽  
pp. 2897-2900
Author(s):  
F. P. Lucas ◽  
R. Huebner
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Single Phase ◽  
Air Flow ◽  
Air Distribution ◽  
Two Phase ◽  
Computational Fluid Dynamics Cfd ◽  
Liquid Removal ◽  
Pipe Inlet

This paper aims to apply computational fluid dynamics (CFD) to simulate air flow and air flow with water droplets, as a reasonable hypothesis for real flows, in order to evaluate a vertical separator vessel with inclined half-pipe inlet device (slope inlet). Thus, this type was compared to a separator vessel without inlet device (straight inlet). The results demonstrated a different performance for the two types in terms of air distribution and liquid removal efficiency.

scholarly journals Aerodynamic Analysis of Spoiler at Varying Speeds and Angles

2021 ◽  
Vol 9 (11) ◽  
pp. 526-535
Author(s):  
Manas Metar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Analysis ◽  
Wake Region ◽  
Aerodynamic Analysis ◽  
Pressure Drag ◽  
High Speeds ◽  
Computational Fluid Dynamics Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results

Abstract: Spoilers have been there in practice since years for the purpose of improving aerodynamics of a car. The pressure drag created at the end of the vehicle, referred to as wake region affects handling of the vehicle. This could be hazardous for the cars at high speeds. By adding a spoiler to the rear of the car reduces that pressure drag and the enhanced downforce helps in better traction. The paper presents aerodynamic analysis of a spoiler through Computational Fluid Dynamics analysis. The spoiler is designed using Onshape software and analyzed through SIMSCALE software. The simulation is carried out by changing angles of attack and velocities. The simulation results of downforce and drag are compared on the basis of analytical method. Keywords: Designing a spoiler, Design and analysis of spoiler, Aerodynamics of spoiler, Aerodynamic analysis of spoiler, Computational fluid dynamics, CFD analysis, CFD analysis of spoiler, Spoiler at variable angles, Types of spoilers, Analytical aerodynamic analysis.

Numerical Simulation of the Inner Flow Field and the Optimal Design of Hema-Type ATY Nozzle Based on Fluent

2013 ◽  
Vol 634-638 ◽  
pp. 3774-3777
Author(s):  
Min Hua Zhang ◽  
Hong Mei Zheng ◽  
Cui Liu ◽  
Yin Hu Qu ◽  
Tao Liang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Optimal Design ◽  
Flow Field ◽  
Flow Fields ◽  
Fluent Software ◽  
Simulation Results

the inner flow fields of twelve Hema-type ATY nozzles which have different structure and parameters are simulated by the Fluent software, which is based on the CFD (Computational Fluid Dynamics) theory.Then the simulation results are analyzed，through wich the best designed nozzle is determined.

Numerical Simulations in the Design of a New Tension-Tethered Marine Current Turbine

2014 ◽  
Author(s):  
David Fernandez ◽  
Jaime Moreu ◽  
Santiago de Guzman ◽  
Ronald W. Yeung ◽  
Manuel Moreu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Test Model ◽  
Pressure Distributions ◽  
Marine Current Turbine ◽  
Marine Current ◽  
Computational Fluid Dynamics Cfd ◽  
Marine Currents ◽  
Simulation Results ◽  
Current Turbine

This paper focuses on the applicability of different Computational Fluid Dynamics (CFD) software for the design of marine current turbines. As part of the conceptual design process, Seaplace has carried out a detailed numerical and experimental hydrodynamic program to optimize a new Tension-Tethered Turbine concept for harnessing energy from marine currents. Three different codes have been assessed, based on the demands from each phase: OpenProp, TurbProp, and ANSYS® CFX®. The paper provides an extensive summary of the main outcomes from the turbine optimization process to achieve highest efficiencies. A description of the tested geometries and the implementation of TurbProp to account for inline turbine solutions is included. Simulations for the test-model and prototype scales have been performed, with the pressure distributions, flow streamlines and power coefficients presented as primary results. The influence of simulation results on the final turbine configurations is discussed.

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