Effects of Compound Groove Texture on Noise of Journal Bearing

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
F. M. Meng ◽  
W. Zhang
Keyword(s):  
Journal Bearing ◽  
Noise Source ◽  
Fluid Dynamic ◽  
Power Level ◽  
Acoustic Power ◽  
Broadband Noise ◽  
Source Theory ◽  
Computation Fluid Dynamic ◽  
Cfd Method ◽  
Groove Texture

The noise of a journal bearing with the compound groove textures is studied based on computation fluid dynamic (CFD) theory and broadband noise source theory. In doing so, the acoustic power levels of the noise for the journal bearing with the compound groove textures and simple ones are separately solved at different geometry sizes and positions of the groove texture, and varied lubricant parameters using CFD method. Numerical results show that the compound groove texture can more effectively lower the acoustic power level of the journal bearing, compared with the simple groove texture. This reduction depends on the groove size and its position, and density and viscosity of the lubricant.

Influences of operation parameters on noise of journal bearing with compound texture considering lubricant thermal effect

2019 ◽  
Vol 234 (7) ◽  
pp. 991-1006
Author(s):  
Fanming Meng ◽  
Ruihong Shu ◽  
Lin Chen
Keyword(s):  
Dynamic Method ◽  
Journal Bearing ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Critical Length ◽  
Broadband Noise ◽  
Three Dimensional Model ◽  
Operation Parameter ◽  
Operation Parameters ◽  
Computation Fluid Dynamic

Effects of operation parameters on the noise of the compound textured journal bearing are analyzed using computation fluid dynamic method and broadband noise source theory. After a three-dimensional model of the compound textured bearing is established, the lubrication performances of the bearing are compared under the isothermal and thermal situations. Further, the noise performances of the textured and smooth bearings are studied at the varied operation parameter. Numerical results show that appropriately decreasing the eccentricity ratio or rotational speed can reduce the noise of the compound textured bearing. Moreover, there is a critical length–diameter ratio of the bearing for suppressing the noise of the compound textured bearing. A part of the above conclusions is also verified experimentally.

scholarly journals CFD Analysis of Journal Bearing with a Heterogeneous Rough/Smooth Surface

Lubricants ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 88
Author(s):  
Mohammad Tauviqirrahman ◽  
J. Jamari ◽  
Arjuno Aryo Wicaksono ◽  
M. Muchammad ◽  
S. Susilowati ◽  
...  
Keyword(s):  
Journal Bearing ◽  
Noise Source ◽  
Journal Bearings ◽  
Broadband Noise ◽  
Load Carrying Capacity ◽  
Computational Investigation ◽  
Roughness Model ◽  
Load Carrying ◽  
Cfd Method ◽  
Lower Noise

In the present study, a computational investigation into acoustic and tribological performances in journal bearings is presented. A heterogeneous pattern, in which a rough surface is engineered in certain regions and is absent in others, is employed to the bearing surface. The roughness is assumed to follow the sand-grain roughness model, while the bearing noise is solved based on broadband noise source theory. Three types of heterogeneous rough/smooth journal bearings exhibiting different placement and number of the rough zone are evaluated at different combinations of eccentricity ratio using the CFD method. Numerical results show that the heterogeneous rough/smooth bearings can supply lower noise and larger load-carrying capacity in comparison with conventional bearings. Moreover, the effect on the friction force is also discussed.

Numerical Analysis of Aerodynamic Noise in a High Parameter Pressure Reducing Valve

2013 ◽  
Vol 397-400 ◽  
pp. 274-277 ◽  
Author(s):  
Lin Wei ◽  
Ming Zhang ◽  
Zhi Jiang Jin ◽  
Li Long Chen
Keyword(s):  
Numerical Analysis ◽  
Noise Source ◽  
Power Level ◽  
Acoustic Power ◽  
Source Model ◽  
Broadband Noise ◽  
Aerodynamic Noise ◽  
High Temperature Steam ◽  
Large Flow ◽  
Pressure Reducing Valve

The high parameter pressure reducing valve (PRV) is a key device for regulating gas pressure in industrial processes. For the large flow and the instability of the high pressure and high temperature steam, the noise of the working PRV is large and also its energy consumption. A numerical analysis of the flow field and acoustic field of the inner high parameter PRV was conducted, the main cause of the aerodynamic noise was analyzed. Basing on the RNG k-ε Model and the Broadband Noise Source Model, the flow and acoustic power are calculated. Comparing the distribution of acoustic power level with the distribution of the velocity and turbulent intensity, it is shown that the main reasons for noise in the PRV are forming and shedding alternately vortexes and shock waves of jet flow.

Prediction of the Aerodynamic Acoustic Power Contribution on Automobile’s Surface Based on Curle’s Integral in Broadband Noise Source Models

2011 ◽  
Vol 317-319 ◽  
pp. 2284-2288
Author(s):  
Zhen Gyu Zheng ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Noise Source ◽  
Power Level ◽  
Research Work ◽  
Acoustic Power ◽  
Broadband Noise ◽  
Vehicle Body ◽  
Aerodynamic Noise ◽  
Source Models

The Aerodynamic noise, which is generated by the moving vehicle at high speed, is a kind of broadband noise. This paper dwelled on the Ligthill’s Acoustic Analogy firstly, and applied the realizable k-ε turbulence model to simulate the external steady flow field of automobile, so as to get the distribution characters of statistical turbulence quantities based on the Reynolds-averaged Navier-Stokes (RANS) equation. Then the Curle’s Integral in Broadband Noise Source Models was utilized to predict the local aerodynamic acoustic power contribution on automobile’s surface, which is helpful to the farther research work in the vehicle body optimization design based on aerodynamic noise controlling. The results shows that: The aerodynamic acoustic power contribution regions on surface mainly distribute near the automobile’s head and tail; and the maximum SAPL (Surface Acoustic Power Level) value is up to 83.15 dB in the vicinity of the rear wheel hub when the vehicle speed is 120km/h; the higher the speed of automobile, the more scattered the distribution of main aerodynamic acoustic power on automobile’s surface.

Numerical Analysis of the Surface Aerodynamic Noise of the CRH3 High Speed Train

2014 ◽  
Vol 1044-1045 ◽  
pp. 643-649
Author(s):  
Ji Zhou Liu ◽  
Ren Xian Li ◽  
Peng Xiang Cui
Keyword(s):  
High Speed ◽  
Noise Source ◽  
Radiation Power ◽  
Spectral Characteristics ◽  
Radiation Energy ◽  
Simulation Method ◽  
Acoustic Power ◽  
Broadband Noise ◽  
Aerodynamic Noise ◽  
High Speed Train

For high speed trains running at 300km/h or more, the aerodynamic noise becomes the primary noise source. A good knowledge of the location, spectral characteristics and propagation behavior of the noise source and the corresponding methods to reduce the effect of the aerodynamic noise are of crucial necessity during the design process of the high speed train. Based on the Lighthill Analogy, the pressure fluctuation of air at the surface of the train is acquired by simulating the flow field of a CRH3 high speed train running at 200 km/h, 300 km/h, 400 km/h and 500km/h by means of large eddy simulation method. By Fourier transformation, the distribution and the spectral characteristics of the surface acoustic dipole sources are obtained. The analysis of the results shows that the aerodynamic noise of the high speed train is a broadband noise with a strong radiation power band from 50Hz to 1000Hz. The dipole acoustic power calculated by statistically averaged on train surface is found to be proportional to the sixth power of running speed of the high speed train. The first and second bogie, the inter-car gap, the air deflector of the power train and the train nose of the last wagon are the main noise sources that contain high radiation energy.

Analysis of the Sound Power Level Emitted by Portable Electric Generators (Outdoor Powered Equipment) Depending on Location and Measuring Surface

2013 ◽  
Vol 430 ◽  
pp. 266-275 ◽  
Author(s):  
Elena Postelnicu ◽  
Valentin Vladut ◽  
Cristian Sorica ◽  
Petru Cardei ◽  
Ion Grigore
Keyword(s):  
Noise Source ◽  
Power Level ◽  
Acoustic Power ◽  
Sound Power ◽  
Noise Emission ◽  
Sound Power Level ◽  
Measuring Surface ◽  
Measurement Surface ◽  
Electric Generators

Acoustic power is a measure which must be specified on the outdoor used equipments and its determination depends on several factors: the place where the equipment works (indoor or outdoor), the placement of the microphones for its determination (the distance less or greater from the noise source), the shape of the measurement surface (parallelepiped or hemispherical). This paper aims to analyze the values obtained in these situations and interpret the data to determine the influence that each factor has on the acoustic power compared with the values obtained (permissible) according to Directive regarding noise emission D 2000/14/EC.

scholarly journals Study and Design Frontal Area of a Car to Curtail Aerodynamic Noise

2021 ◽  
Vol 9 (8) ◽  
pp. 1637-1652
Author(s):  
Smit Shendge
Keyword(s):  
Fluid Dynamics ◽  
Turbulence Model ◽  
Noise Analysis ◽  
Power Level ◽  
Acoustic Power ◽  
Broadband Noise ◽  
Noise Model ◽  
Aerodynamic Noise ◽  
Aerodynamic Analysis ◽  
Car Model

Abstract: In this field of comparative research study, comparison of two car model, a standard car and an optimized car with respect to aerodynamic analysis/aeroacoustics analysis with the help of CFD software Ansys 2019 R2 version is taken in consideration to compare the results and get to know if the optimized car model has reduction in the generation of aerodynamic noise when it travels at four different speeds (30 m/s, 40 m/s, 50m/s and 60m/s). For carried out aeroacoustics/aerodynamic noise analysis two main model are used turbulence model and an acoustics model. For turbulence model and K-epsilon model is used as it is widely used for getting turbulence generation and for acoustics model a Broadband noise model is used to generate the results through numerical simulation and data sources. First a standard sedan car is modelled in Onshape CAD tool and aeroacoustics analysis is carried out on this standard sedan car to get to know the source of aerodynamic noise. From the standard car results made changes in the sedan car geometry like giving fillets to point/sharp edges of wheel arcs, front bumper, hood-line, fender and start of roofline from A-pillar, providing under-flush, optimizing A-pillar beam and optimizing outside rear view mirror and making them fully camera integrated mirror to reduce wake. After optimizing standard geometry carried out aerodynamic analysis with the same four different speed given for standard car (30 m/s, 40m/s, 50m/s and 60 m/s). Generated contour plots and isosurface from CFX for flow characteristics and acoustic sound source with various model like Proudman’s acoustic power level in Db, Curle surface acoustic power level in decibels (dB) and also, Lilley S total noise source to show the sources of noise and how many decibels of noise is generated from those sources. Maximum of 100 decibels of noise is generated from the front bumper and a minimum of 80 decibels were monitored in the results process after comparing the results with standard car which has noise nearly 120 decibels with high fluctuations of turbulence kinetic energy and decrease in its pressure level. Keyword: Aeroacoustics, Aerodynamic noise, Aeolin sound, Fluid dynamics, NVH (noise, vibration and harshness) and CFD (computational fluid dynamics).

scholarly journals Influence of boundary slip layout on the hydrodynamic performance of partially textured journal bearing by CFD method

2018 ◽  
Vol 204 ◽  
pp. 04008 ◽  
Author(s):  
Mohammad Tauviqirrahman ◽  
Muchammad ◽  
Rizky Amanullah Akbar ◽  
Jamari
Keyword(s):  
Computational Fluid Dynamic ◽  
Journal Bearing ◽  
Fluid Dynamic ◽  
Hydrodynamic Pressure ◽  
Combined Effect ◽  
Hydrodynamic Performance ◽  
Textured Surface ◽  
Eccentricity Ratio ◽  
Boundary Slip ◽  
Cfd Method

Modification of the lubricated surface by combining the boundary slip and the texturing has proven to enhance the hydrodynamic performance of bearing. The present work explores the combined effect of boundary slip and texturing varying slip layout on the performance of journal bearing using computational fluid dynamic (CFD) approach. The effect of eccentricity ratio is also of particular interest. The results show that when the boundary slip is located on all edges of textured surface, more enhanced load support by 4% is obtained in comparison with classical (no-slip) textured one. However, in general the results also indicate that introducing the boundary slip with different layouts on partially textured surface does not much affect the hydrodynamic pressure as well as the load support; therefore, the slip-textured bearing shows similar and closer trend to the no-slip textured one. In addition, it is also found that the effect of eccentricity ratio is more influential than the boundary slip in terms of load support.

Three-dimensional computational fluid dynamic analysis of high-speed water-lubricated hydrodynamic journal bearing with groove texture considering turbulence

2021 ◽  
pp. 135065012199851
Author(s):  
Huihui Feng ◽  
Shuyun Jiang ◽  
Yanqin Shang-Guan
Keyword(s):  
Computational Fluid Dynamic ◽  
High Speed ◽  
Journal Bearing ◽  
Fluid Dynamic ◽  
Load Capacity ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Computational Fluid Dynamic Analysis ◽  
Hydrodynamic Journal Bearing ◽  
Groove Texture

Water-lubricated bearings have attracted increasing attention in the field of high-speed machine tools for their low friction due to low viscosity. However, new problems, in particular, insufficient load capacity, are on the way. To the point, groove-textured journal bearing is adopted in this study. Aiming at investigating the effects of groove texture on high speed, water-lubricated, hydrodynamic journal bearing precisely, and thoroughly, three-dimensional computational fluid dynamic analyses considering cavitation and turbulence are undertaken to assess the tribological performances of the bearing. To reduce the amount of three-dimensional modeling and meshing work, mesh deformation is presented. The numerical results are compared with experiments to verify the validity of the present models and calculation procedures. Pressure distribution, load capacity, and friction of groove-textured water-lubricated journal bearing are analyzed with respect to operating conditions and geometric parameters. Comparisons between groove-textured water-lubricated journal bearing and smooth bearing are carried out to find out the influence of groove texture. It is found that the groove texture can achieve a remarkable improvement of load capacity at a smaller eccentricity ratio and higher rotary speed. The load capacity is affected by the combined effects of groove depth, width, and length. However, generally, the friction force of water-lubricated journal bearing is slightly influenced by groove texture. Results can provide theoretical guidance for the optimal design of groove-textured water-lubricated journal bearing under different operating parameters.

Physics-informed Broadband Noise Source Identification and Prediction of an Ideally Twisted Rotor

2021 ◽  
Author(s):  
Christopher Thurman ◽  
Nikolas S. Zawodny ◽  
Nicole A. Pettingill ◽  
Leonard V. Lopes ◽  
James D. Baeder
Keyword(s):  
Source Identification ◽  
Noise Source ◽  
Broadband Noise ◽  
Noise Source Identification
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