A Thermohydrodynamic Analysis of Large Tilting-Pad Journal Bearing in Laminar and Turbulent Flow Regimes With Mixing

1990 ◽  
Vol 112 (3) ◽  
pp. 542-548 ◽  
Author(s):  
S. Taniguchi ◽  
T. Makino ◽  
K. Takeshita ◽  
T. Ichimura
Keyword(s):  
Turbulent Flow ◽  
Flow Model ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Flow Regimes ◽  
Inlet Temperature ◽  
Tilting Pad ◽  
Laminar And Turbulent Flow ◽  
Tilting Pad Journal Bearing ◽  
Good Agreement

This paper describes a thermohydrodynamic analysis of the 19 in. diameter tilting-pad journal bearing for steam turbine in comparison with experimental data. The three-dimensional thermohydrodynamic analysis is performed in both laminar and turbulent flow regimes considering mixing inlet temperature. The linearized turbulent flow model derived by Ng and Pan (1965) is applied. Generally good agreement is obtained for bearing surface temperatures, frictional losses, and minimum film thicknesses between the theoretical and experimental results.

Improvement and Analysis for a Gaseous Cavitation Model Applied in a Tilting-Pad Journal Bearing

2019 ◽  
Author(s):  
Aoshuang Ding ◽  
Xuesong Li ◽  
Yuhong Li
Keyword(s):  
Journal Bearing ◽  
Three Dimensional ◽  
Cavitation Model ◽  
Local Pressure ◽  
Cavitation Process ◽  
Air Volume ◽  
Tilting Pad ◽  
Sst Model ◽  
Tilting Pad Journal Bearing ◽  
Good Agreement

Abstract Considering the gaseous cavitation rate is influenced by local pressure, a transient gaseous cavitation model is developed from an equilibrium gaseous cavitation model in consideration of transient gaseous cavitation theories and the Bunsen solubility. With the shear stress transport (SST) model with low-Re correction and air backflow from the bearing outlets, the transient gaseous cavitation model is applied to the three-dimensional simulations of an entire tilting-pad journal bearing at 3000 rpm speed and under 180 kN load. The simulated bearing pressure and load are in good agreement with the experimental data, indicating that the transient gaseous cavitation model performs well in the bearing simulations. Based on the comparisons of the simulated air and dissolved air distributions between the transient and equilibrium gaseous cavitation models, the simulated cavitation process of the transient gaseous cavitation is proved to be not in equilibrium and mass transfer occur between the backflow air and oil. The purpose of building the transient gaseous cavitation model is thus met. Analyses of the air distributions indicate that high cavitation rates and low dissolution rates makes air volume a major part of the total air volume and close to the physical gaseous cavitation process.

The Steady-State and Dynamic Characteristics of the Tilting-Pad Journal Bearing in Laminar and Turbulent Flow Regimes

1967 ◽  
Vol 89 (3) ◽  
pp. 392-400 ◽  
Author(s):  
F. K. Orcutt
Keyword(s):  
Steady State ◽  
Turbulent Flow ◽  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Calculated Data ◽  
Operating Parameters ◽  
Experimental Measurements ◽  
Tilting Pad ◽  
Laminar And Turbulent Flow ◽  
Tilting Pad Journal Bearing

Calculated steady-state and dynamic characteristics are given for the four-pad, tilting-pad journal bearing with preload coefficients of 0 and 0.5 and for mean Reynolds up to 12,000. The calculated characteristics are compared with experimental measurements over the same range of operating parameters. Correlation is good, leading to the conclusion that the calculated data are effective for design analysis of rotor-bearing systems using tilting-pad bearings.

Three-Dimensional Thermo-Elasto-Hydrodynamic Computational Fluid Dynamics Model of a Tilting Pad Journal Bearing—Part II: Dynamic Response

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Jongin Yang ◽  
Alan Palazzolo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamic Response ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Static Response ◽  
Damping Coefficients ◽  
Tilting Pad ◽  
Stiffness And Damping ◽  
Tilting Pad Journal Bearing

Part II presents a novel approach for predicting dynamic coefficients for a tilting pad journal bearing (TPJB) using computational fluid dynamics (CFD) and finite element method (FEM), including fully coupled elastic deflection, heat transfer, and fluid dynamics. Part I presented a similarly novel, high fidelity approach for TPJB static response prediction which is a prerequisite for the dynamic characteristic determination. The static response establishes the equilibrium operating point values for eccentricity, attitude angle, deflections, temperatures, pressures, etc. The stiffness and damping coefficients are obtained by perturbing the pad and journal motions about this operating point to determine changes in forces and moments. The stiffness and damping coefficients are presented in “synchronously reduced form” as required by American Petroleum Institute (API) vibration standards. Similar to Part I, an advanced three-dimensional thermal—Reynolds equation code validates the CFD code for the special case when flow Between Pad (BP) regions is ignored, and the CFD and Reynolds pad boundary conditions are made identical. The results show excellent agreement for this validation case. Similar to the static response case, the dynamic characteristics from the Reynolds model show large discrepancies compared with the CFD results, depending on the Reynolds mixing coefficient (MC). The discrepancies are a concern given the key role that stiffness and damping coefficients serve instability and response predictions in rotordynamics software. The uncertainty of the MC and its significant influence on static and dynamic response predictions emphasizes a need to utilize the CFD approach for TPJB simulation in critical machines.

scholarly journals Thermal Turbulent Flow in Leading Edge Grooved and Conventional Tilting Pad Journal Bearing Segments—A Comparative Study

Lubricants ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 97 ◽  
Author(s):  
Philip Croné ◽  
Andreas Almqvist ◽  
Roland Larsson
Keyword(s):  
Comparative Study ◽  
Journal Bearing ◽  
Flow Characteristics ◽  
Leading Edge ◽  
Inlet Temperature ◽  
Average Value ◽  
Tilting Pad ◽  
Sst Turbulence Model ◽  
Effective Boundary Condition ◽  
Tilting Pad Journal Bearing

A comparative study between a conventional- and leading edge grooved (LEG) tilting pad journal bearing (TPJB) segment is performed. The developed model uses the Shear Stress Transport (SST) turbulence model, coupled with the energy equation and a partial differential equation for the fluid domain mesh displacement to predict the thermal flow characteristics. Instead of using an effective boundary condition to determine the inlet temperature of the LEG pad and excluding the additional LEG portion, as is common practice, the whole geometry of the LEG is modeled. Several sizes of the LEG portion is investigated and it is shown to have quite a small influence on pressure, temperature, film thickness and turbulence intensity. Moreover, the results also show that the conventional pad gives rise to higher levels of turbulence in the mid plane compared to its LEG counterpart, while the latter has a marginally higher value of turbulence when the volume average value is computed. The maximum value of turbulence is however present in the conventional model.

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