International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 10 Issue: 05 | May 2023
p-ISSN: 2395-0072
www.irjet.net
FINITE ELEMENT ANALYSIS OF GAS FOIL BEARINGS Srinath Ingale1, Sushant Mane2, Sanket More3, Vishal More4, Swaraj Kashid5, Aditya More6 1Assistant Professor of Mechanical Department, Dr. A. D. Shinde Collage of Engineering, Gadhinglaj-416502,
Maharashtra, India
2,3,4,5,6 Student of Mechanical Department, Dr. A. D. Shinde Collage of Engineering, Gadhinglaj-416502,
Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------2. MODELLING PARAMETERS OF BEARING Abstract - Micro turbomachinery demands gas comportments to be light compact and should operate at varying temperature conditions. Low heat generation disunion and lack of lubricant rotation system makes it compact dependable andeco-friendly. still low stiffness and damping portions, high cost and lack of sufficient knowledge and prophetic tools kindly restricts GFBs use in mass produced operation. Current marketable and engineering operation demands further and more aggressive designs with high face speed and unit loads as well as thinner fluid film. Again rotordynamics analysis uses stiffness and damping portions to represent fluid film geste or in other words these portions play the crucial part in determining dynamic characteristics of a rotor shaft. Stiffness portions depend substantially on two factors first the static deviation of antipode due to shaft cargo and second the hydrodynamic effect produced due to the fluid film. Then's an approach to calculate the stiffness measure produced due to static deviation of GFBs due to static cargo using finite element analysis and the stiffness measure has been calculated. Reynold’s equation is to be answered using FDM to gain pressure profile during hydrodynamic action of fluid film and using these pressure values in the bearing model dynamic element of stiffness can be produced. Adding both factors will produce the overall stiffness measure of a gas antipode bearing.
Table-1: Parameters and dimensions of 3 gas foil bearings to be modelled and analyzed Serial no.
Parameter
GFB1
GFB2
GFB3
1
Journal diameter
28.5mm
25mm
30mm
2
Journal length
28.5mm
25mm
30mm
3
Film clearance
.020mm .020mm .020mm
4
Foil thickness (top & bump)
127μm
150μm
300μm
5
Number of bumps
40
36
40
6
Bump height
580μm
580μm
580μm
7
Bump pitch
1.2mm
1.3mm
1.15mm
8
Bump diameter
1mm
1mm
1mm
9
Bump foil Young’s modulus
200Gpa
200Gpa
200Gpa
10
Bump foil Poisson’s ratio
0.31
0.31
0.31
Key Words: FEA, gas foil bearing, stiffness coefficients.
1. INTRODUCTION A bearing is a mechanical device that separates two opposing shells fully by a subcaste of fluid lubricant. Plain journal bearing is used commercially in nearly all bias that has a rotating part. Compressors, pumps turbines, motors creators are many exemplifications need to be mentioned. Journal bearing is a structure where two cylinders rotate concentrically relative to each other. One being the shaft, rotating at a particular angular speed, and other the bearing. The main ideal is to support the rotating structures and give sufficient lubrication to avoid disunion that causes wear and tear and gash to machine corridor. The fluid film at high pressure provides the hydrodynamic film lubrication and determines the cargo capacity of the bearing. curiosity is a bearing parameter which is defined as the relegation between shaft and bearing center.
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Impact Factor value: 8.226
Figure- 3: Schematic view of extended bump strips and a typical bump foil bearing
3. FINITE ELEMENT ANALYSIS USING ANSYS 3.1 GENERATION OF MESH Generating mesh is the most important and critical work in engineering simulation in Ansys software. Large no of cells may take longer time to produce solutions without increasing accuracy whereas very few number of cells might produce inaccurate results.
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