scholarly journals Discussion: “Thermohydrodynamic Analysis of Tilting-Pad Journal Bearings Operating in Turbulent Flow Regime” (Bouard, L., Fillon, M., and Frene, J., 1996, ASME J. Tribol., 118, pp. 225–231)

1997 ◽  
Vol 119 (1) ◽  
pp. 229-229
Author(s):  
A. Z. Szeri
Keyword(s):  
Turbulent Flow ◽  
Flow Regime ◽  
Journal Bearings ◽  
Turbulent Flow Regime ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearings

Thermohydrodynamic Analysis of Tilting-Pad Journal Bearings Operating in Turbulent Flow Regime

1996 ◽  
Vol 118 (1) ◽  
pp. 225-231 ◽  
Author(s):  
L. Bouard ◽  
M. Fillon ◽  
J. Freˆne
Keyword(s):  
Turbulent Flow ◽  
Flow Regime ◽  
Local Heat ◽  
Journal Bearings ◽  
Local Analysis ◽  
Maximum Temperature ◽  
Turbulent Flow Regime ◽  
Tilting Pad ◽  
Local Heat Flux ◽  
Tilting Pad Journal Bearings

A thermohydrodynamic analysis of tilting-pad bearing in turbulent flow regime is presented. Two tilting-pad journal bearings are studied. A local analysis of thermal turbulent phenomena is shown. The theoretical prediction of the maximum temperature decreases when the flow regime becomes nonlaminar and the decrease corresponding to higher power losses is explained using the velocity component profiles and the local heat flux in the film.

A Thermoelastohydrodynamic Analysis for the Static Performance of High-Speed Heavy Load Tilting-Pad Journal Bearing Operating in the Turbulent Flow Regime and Comparisons to Test Data

2018 ◽  
Author(s):  
Hirotoshi Arihara ◽  
Yuki Kameyama ◽  
Yoshitaka Baba ◽  
Luis San Andrés
Keyword(s):  
Turbulent Flow ◽  
Flow Regime ◽  
Flow Rate ◽  
Power Loss ◽  
High Speed ◽  
Hydrodynamic Pressure ◽  
Thermally Induced ◽  
Turbulent Flow Regime ◽  
Tilting Pad ◽  
Static Performance

Tilting-pad journal bearings (TPJBs) ensure rotordynamic stability that could otherwise produce dangerously large amplitude rotor oil-whirl/whip motions in high speed rotating machinery. Currently, highly efficient turbo compressors demand an ever increasing rotor surface speed and specific load on its support bearings. The accurate prediction of bearing performance is vital to guarantee reliable products, specifically with regard to reducing maximum bearing pad temperature and drag power losses, and operating with the least flow rate while still maximizing load capacity. The hydrodynamic pressure and heat generation in an oil film acting on a bearing pad produce significant mechanical and thermal deformations that change the oil film geometry (clearance and preload) to largely affect the bearing performance, static and dynamic. In addition, a high surface speed bearing often operates in the turbulent flow regime that produces a notable increase in power loss and a drop in maximum pad temperature. This paper details a thermoelastohydrodynamic (TEHD) analysis model applied to TPJBs, presents predictions for their steady-load performance, and discusses comparisons with experimental results to validate the model. The test bearing has four pads with a load between pads configuration; its length L = 76.2 mm and shaft diameter D = 101.6 mm (L/D = 0.75). The rotor top speed is 22.6 krpm, i.e. 120 m/s surface speed, and the maximum specific load is 2.94 MPa for an applied load of 23 kN. The test procedure records shaft speed and applied load, oil supply pressure/temperature and flow rate, and also measures the pads’ temperature and shaft temperature, as well as the discharge oil (sump) temperature. The TEHD model couples a generalized Reynolds equation for the hydrodynamic pressure generation with a three-dimensional energy transport equation for the film temperature. The pad mechanical deformation due to pressure utilizes the finite elemental method, whereas an analytical model estimates thermally induced pad crowning deformations. For operation beyond the laminar flow regime, the analysis incorporates the eddy viscosity concept for fully developed turbulent flow operation. Current predictions demonstrate the influence of pressure and temperature fields on the pads mechanical and thermally induced deformation fields, and also show static performance characteristics such as bearing power loss, flow rate, and pad temperatures. The comparisons of test results and analysis results reveal that turbulent flow effects significantly reduce the pads’ maximum temperature while increasing the bearing power loss. Turbulent flow mixing increases the diffusion of thermal energy and makes more uniform the temperature profile across the film.

scholarly journals Performance Characteristics of Elliptical Journal Bearings in Turbulent Flow Regime

1984 ◽  
Vol 27 (232) ◽  
pp. 2265-2271 ◽  
Author(s):  
Hiromu HASHIMOTO ◽  
Sanae WADA ◽  
Hiroaki TSUNODA
Keyword(s):  
Turbulent Flow ◽  
Flow Regime ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Turbulent Flow Regime

A Thermoelastohydrodynamic Analysis for the Static Performance of High-Speed—Heavy Load Tilting-Pad Journal Bearing Operating in the Turbulent Flow Regime and Comparisons to Test Data

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Hirotoshi Arihara ◽  
Yuki Kameyama ◽  
Yoshitaka Baba ◽  
Luis San Andrés
Keyword(s):  
Turbulent Flow ◽  
Flow Regime ◽  
Flow Rate ◽  
Power Loss ◽  
High Speed ◽  
Hydrodynamic Pressure ◽  
Thermally Induced ◽  
Turbulent Flow Regime ◽  
Tilting Pad ◽  
Static Performance

Tilting-pad journal bearings (TPJBs) ensure rotordynamic stability that could otherwise produce dangerously large amplitude rotor oil-whirl/whip motions in high-speed rotating machinery. Currently, highly efficient turbo compressors demand an ever increasing rotor surface speed and specific load on its support bearings. The accurate prediction of bearing performance is vital to guarantee reliable products, specifically with regard to reducing maximum bearing pad temperature and drag power losses, and operating with the least flow rate while still maximizing load capacity. The hydrodynamic pressure and heat generation in an oil film acting on a bearing pad produce significant mechanical and thermal deformations that change the oil film geometry (clearance and preload) to largely affect the bearing performance, static, and dynamic. In addition, a high surface speed bearing often operates in the turbulent flow regime that produces a notable increase in power loss and a drop in maximum pad temperature. This paper details a thermoelastohydrodynamic (TEHD) analysis model applied to TPJBs, presents predictions for their steady-load performance, and discusses comparisons with experimental results to validate the model. The test bearing has four pads with a load between pads configuration; its length L = 76.2 mm and shaft diameter D = 101.6 mm (L/D = 0.75). The rotor top speed is 22.6 krpm, i.e., 120 m/s surface speed, and the maximum specific load is 2.94 MPa for an applied load of 23 kN. The test procedure records shaft speed and applied load, oil supply pressure/temperature and flow rate, and also measures the pads' temperature and shaft temperature, as well as the discharge oil (sump) temperature. The TEHD model couples a generalized Reynolds equation for the hydrodynamic pressure generation with a three-dimensional energy transport equation for the film temperature. The pad mechanical deformation due to pressure utilizes the finite elemental method, whereas an analytical model estimates thermally induced pad crowning deformations. For operation beyond the laminar flow regime, the analysis incorporates the eddy viscosity concept for fully developed turbulent flow operation. Current predictions demonstrate the influence of pressure and temperature fields on the pads mechanical and thermally induced deformation fields and also show static performance characteristics such as bearing power loss, flow rate, and pad temperatures. The comparisons of test results and analysis results reveal that turbulent flow effects significantly reduce the pads' maximum temperature while increasing the bearing power loss. Turbulent flow mixing increases the diffusion of thermal energy and makes more uniform the temperature profile across the film.

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