Research on dynamic characteristics of gas film of spherical hybrid gas bearings based on computational fluid dynamics

A realizable k–ε turbulence model for spherical spiral groove hybrid gas bearing films was established based on computational fluid dynamics (CFD). A six degrees of freedom passive grid was used to calculate the gas film pressure distribution, bearing capacity, and dynamic characteristic coefficients numerically. The gas flow field dynamic and static pressure coupling mechanism was studied. The effects of the rotation speed, gas film thickness eccentricity ratio, and gas supply pressure on the dynamic and static pressure bearing capacity, and dynamic characteristic coefficients during operation were analyzed as a method of research into the mechanical mechanisms of gas bearing stability. The CFD calculation analysis can simulate the complex gas flow in the transient flow field of the gas film and determine reasonable operation parameters to optimize the dynamic and static pressure coupling effects, which can improve the gas film bearing capacity, dynamic characteristics, and operational stability of gas bearings.

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Study on Characteristics of Gas Flow in Catalytic Converter with Different Outlet Diameters

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.711.16 ◽

2014 ◽

Vol 711 ◽

pp. 16-19

Author(s):

Zhan Jun Cai ◽

Wei Min Kang ◽

Ya Bin Li

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Catalytic Reaction ◽

Gas Flow ◽

Static Pressure ◽

Catalytic Converter ◽

Geometric Model ◽

Flow Pressure ◽

Different Diameters ◽

Dynamics Method

. This paper studies the different diameters of tube outlet how to affect the gas flow pressure and velocity distribution in nanofiber catalytic converter by CFD (Computational Fluid Dynamics) method. Geometric model of the catalytic converter has been established and meshed by the pre-processing tool of FLUENT. The distribution of velocity and pressure in the converter which outlet diameter is 70 mm is more evenly than the converter which outlet diameter is 50 mm. It is conducive to reducing airflow static pressure in the catalytic converter that expanding the outlet diameter in the case of other conditions remains unchanged. Therefore, the larger outlet diameter is beneficial to exhaust catalytic reaction.

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Research of 3D-CFD Simulation on a Large Sized Pit Type Carburizing Furnace

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.118.337 ◽

2006 ◽

Vol 118 ◽

pp. 337-342

Author(s):

Wei Min Zhang ◽

Ye Ma ◽

Lin Lin Li

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Flow Field ◽

Gas Flow ◽

Cfd Simulation ◽

Fluid Dynamic ◽

Cfd Simulations ◽

3 Dimensional ◽

Set Up ◽

Carburizing Process

A fluid dynamic model was set up to describe the flow field of gas in a large sized pit type carburizing furnace when large sized gears were being carburized. The commercial software Fluent was adopted to carry out 3 dimensional computational fluid dynamics (3D-CFD) simulations of the gas flow field under different, actually four kinds of , furnace designs in this article. The flow fields of the carburizing gas around the part were analyzed. According to the simulations and analysis, it was shown that the number of fans on gear’s carburizing is not a primary factor, using a air inducting tub can improve the carburizing process significantly and proper loading tray design can also be positive. The results indicate that the simulation provides a reference to the furnace’s design optimization.

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Optimization of Channel Width Distribution of a Gas Flow Field by Integrating Computational Fluid Dynamics Code with a Simplified Conjugate-Gradient Method

Energy & Fuels ◽

10.1021/ef9007455 ◽

2010 ◽

Vol 24 (1) ◽

pp. 570-580 ◽

Cited By ~ 8

Author(s):

Jiin-Yuh Jang ◽

Chin-Hsiang Cheng ◽

Yu-Xian Huang

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Flow Field ◽

Conjugate Gradient Method ◽

Conjugate Gradient ◽

Gradient Method ◽

Gas Flow ◽

Channel Width ◽

Width Distribution ◽

Gas Flow Field

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The Hydraulic Characteristics of Inner Loop Biological Fluidized Bed Set Ring-Type Baffle

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.807-809.1147 ◽

2013 ◽

Vol 807-809 ◽

pp. 1147-1150

Author(s):

Zhan Xiu Chen ◽

Juan Men

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Flow Field ◽

Fluidized Bed ◽

Turbulence Intensity ◽

Static Pressure ◽

Fluidized Bed Reactor ◽

Hydraulic Characteristics ◽

Ring Type ◽

Static Pressure Difference

The flow field of the traditional inner loop biological fluidized bed reactor (ILBFBR) and a new biological fluidized bed reactor set ring-type baffle was calculated by computational fluid dynamics. The results show that the gas holdup of drop zone in ILBFBR set the ring-type baffle can increase significantly, the flow rate of drop zone in ILBFBR with the ring-type baffle is faster than that in traditional ILBFBR, and turbulence intensity distributed more evenly all in rising zone and drop zone in ILBFBR set the ring-type baffle than that in traditional ILBFBR, but static pressure difference of ILBFBR set ring-type baffle is higher than that of the traditional ILBFBR.

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Construction Ventilation Scheme Optimization of Underground Main Powerhouse Based on CFD

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.368-370.619 ◽

2013 ◽

Vol 368-370 ◽

pp. 619-623

Author(s):

Zhen Liu ◽

Xiao Ling Wang ◽

Ai Li Zhang

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Flow Field ◽

Air Flow ◽

Scheme Optimization ◽

Pressure Distributions ◽

Air Volume ◽

Computational Fluid Dynamics Cfd ◽

Traditional Construction ◽

Ventilation Scheme

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.

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Effect of Doppler flow meter position on discharge measurement in surcharged manholes

Water Science & Technology ◽

10.2166/wst.2017.563 ◽

2017 ◽

Vol 77 (3) ◽

pp. 647-654 ◽

Cited By ~ 1

Author(s):

Haoming Yang ◽

David Z. Zhu ◽

Yanchen Liu

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Flow Field ◽

Flow Regimes ◽

Flow Meter ◽

Flow Meters ◽

Flow Discharge ◽

Doppler Flow ◽

Sewer Systems ◽

Computational Fluid Dynamics Cfd

Abstract Determining the proper installation location of flow meters is important for accurate measurement of discharge in sewer systems. In this study, flow field and flow regimes in two types of manholes under surcharged flow were investigated using a commercial computational fluid dynamics (CFD) code. The error in measuring the flow discharge using a Doppler flow meter (based on the velocity in a Doppler beam) was then estimated. The values of the corrective coefficient were obtained for the Doppler flow meter at different locations under various conditions. Suggestions for selecting installation positions are provided.

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The Effect of Different Turbulence Models on the Emitter Discharge by Using Computational Fluid Dynamics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.662.586 ◽

2013 ◽

Vol 662 ◽

pp. 586-590

Author(s):

Gang Lu ◽

Qing Song Yan ◽

Bai Ping Lu ◽

Shuai Xu ◽

Kang Li

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Flow Field ◽

Turbulence Models ◽

Experimental Results ◽

Turbulent Model ◽

Simulation Results ◽

Rsm Model ◽

Dynamics Method ◽

Emitter Discharge

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.

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Numerical Investigation of Thermal Flow Field of Air-Cooled Condensers for Yongshou Plant

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.248.391 ◽

2012 ◽

Vol 248 ◽

pp. 391-394

Author(s):

Wen Zhou Yan ◽

Wan Li Zhao ◽

Qiu Yan Li

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Wind Speed ◽

Power Plant ◽

Flow Field ◽

Wind Direction ◽

Rotational Speed ◽

Power Plants ◽

Thermal Flow ◽

Air Cooled Condensers

By using the computational fluid dynamics code, FLUENT, Numerically simulation is investigated for Youngshou power plant. Under the constant ambient temperature, the effects of different wind speed and wind direction on the thermal flow field are qualitatively considered. It was found that when considering about the existing and normally operating power plants, the thermal flow field is more sensitive to wind direction and wind speed. Based on the above results, three improved measures such as: increasing the wind-wall height and accelerating the rotational speed of the fans near the edge of the ACC platform and lengthen or widen the platform are developed to effectively improving the thermal flow field, and enhanced the heat dispersal of ACC.

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CFD Leakage Predictions of Unworn and Worn Labyrinth Seals With and Without Tooth Axial Offset

Volume 5B: Heat Transfer ◽

10.1115/gt2017-63163 ◽

2017 ◽

Author(s):

Hasham H. Chougule ◽

Alexander Mirzamoghadam

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Numerical Modeling ◽

Steady State ◽

Flow Field ◽

Labyrinth Seals ◽

Small Clearance ◽

Total Leakage ◽

Computational Fluid Dynamics Cfd ◽

Flow Deflection

The objective of this study is to develop a Computational Fluid Dynamics (CFD) based methodology for analyzing and predicting leakage of worn or rub-intended labyrinth seals during operation. The simulations include intended tooth axial offset and numerical modeling of the flow field. The purpose is to predict total leakage through the seal when an axial tooth offset is provided after the intended/unintended rub. Results indicate that as expected, the leakage for the in-line worn land case (i.e. tooth under rub) is higher compared to unworn. Furthermore, the intended rotor/teeth forward axial offset/shift with respect to the rubbed land reduces the seal leakage. The overall leakage of a rubbed seal with axial tooth offset is observed to be considerably reduced, and it can become even less than a small clearance seal designed not to rub. The reduced leakage during steady state is due to a targeted smaller running gap because of tooth offset under the intended/worn land groove shape, higher blockages, higher turbulence and flow deflection as compared to worn seal model without axial tooth offset.

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