Additively Manufactured Compliant Hybrid Gas Thrust Bearing for sCO2 Turbomachinery: Experimental Evaluation and Fluid-Structure Model Predictions

2021 ◽  
Author(s):  
Bugra Ertas ◽  
Keith Gary ◽  
Adolfo Delgado
Keyword(s):  
Experimental Evaluation ◽  
Thrust Bearing ◽  
Structure Model ◽  
Fluid Structure ◽  
Model Predictions

Additively Manufactured Compliant Hybrid Gas Thrust Bearing for SCO2 Turbomachinery: Experimental Evaluation & Fluid-Structure Model Predictions

2021 ◽  
Author(s):  
Bugra Ertas ◽  
Keith Gary ◽  
Adolfo Delgado
Keyword(s):  
Thrust Bearing ◽  
Load Capacity ◽  
Ideal Gas ◽  
Squeeze Film ◽  
Outer Diameter ◽  
Structure Model ◽  
Unit Load ◽  
Free System ◽  
Fluid Structure ◽  
Process Gas

Abstract The following paper presents test results and advances an analytical predictive fluid-structure model for a new type of gas lubricated thrust bearing fabricated using direct metal laser melting (DMLM). The concept in the present study is a compliant hybrid gas thrust bearing using external pressurization to increase load carrying capacity, where the testing in the present study only focused on steady state static performance. The need for the bearing concept comes from enabling highly efficient supercritical carbon dioxide (sCO2) turbomachinery by replacing oil-lubricated bearings with process gas lubrication. Leveraging the process gas for bearing lubrication results in lowered bearing power loss [1], simplified mechanical design, and allows for novel oil-free hermetic drivetrains resulting in an efficient emission-free system [2,3]. The new concept utilizes hydrostatic pressurization on individual tilting pads flexibly mounted with hermetic squeeze film dampers (HSFD). The paper focuses on tests of a 173mm outer diameter gas thrust bearing in air up to 10krpm and hydrostatic inlet pressures to 365psi (2.52MPa). The present work advances a fluid-structure thrust bearing model using an isothermal ideal-gas based Reynolds flow equation coupled to a lumped stiffness element possessing axial and rotational degrees of freedom. The rotating testing demonstrated load capability of 1,816 lbs (8.1KN), which equates to a thrust bearing unit load of 67psi (0.46 MPa). Load capability was shown to increase with increasing hydrostatic inlet pressure while the increase in thrust runner speed revealed a small decrease in load capacity.

Additively Manufactured Compliant Hybrid Gas Thrust Bearing for sCO2 Turbomachinery: Experimental Evaluation and Fluid-Structure Model Predictions

2020 ◽  
Author(s):  
Bugra Ertas ◽  
Keith Gary ◽  
Adolfo Delgado
Keyword(s):  
Thrust Bearing ◽  
Load Capacity ◽  
Inlet Pressure ◽  
Squeeze Film ◽  
Outer Diameter ◽  
Structure Model ◽  
Free System ◽  
Fluid Structure ◽  
Process Gas ◽  
Load Carrying

Abstract The following paper presents rotating test results and advances an analytical predictive fluid-structure model for a new type of gas lubricated thrust bearing fabricated using direct metal laser melting (DMLM). The bearing concept in the present study is a compliant hybrid gas thrust bearing that uses external pressurization to increase load carrying capacity, where the testing campaign in the present study was only focused on steady state static performance. The need for the bearing concept comes from enabling highly efficient supercritical carbon dioxide (sCO2) turbomachinery by replacing oil-lubricated bearings with process gas lubrication. Leveraging the process gas of the turbomachine for bearing lubrication results in lowered bearing power loss [1], simplified mechanical design, and allows for novel oil-free hermetic drivetrains resulting in an efficient emission-free system [2,3]. The new concept utilizes hydrostatic pressurization on individual tilting pads flexibly mounted with hermetic squeeze film dampers (HSFD). The paper focuses on rotating tests of a 173mm outer diameter gas thrust bearing in air up to 10krpm and hydrostatic inlet pressures to 365psi (2.52MPa). The influence of thrust runner speed and bearing inlet pressure on force deflection characteristics and load carrying capability of the gas film were experimentally evaluated. The present work also advances a predictive fluid-structure thrust bearing model using an isothermal ideal-gas based compressible Reynolds flow equation directly coupled to a lumped stiffness element possessing axial and rotational degrees of freedom. The rotating testing demonstrated load capability of 1,816 lbs (8.1KN), which equates to a thrust bearing unit load of 67psi (0.46 MPa). Gas film force-deflection curves reveal a nonlinear relationship between thrust load and film clearance. Comparison of film thickness values with the predictive model show good agreement under high load and inlet pressure, however deviate as load and pressure decrease. Load capability was shown to increase with increasing hydrostatic inlet pressure while the increase in thrust runner speed revealed a small decrease in load capacity.

scholarly journals A simplified fluid–structure model for arterial flow. Application to retinal hemodynamics

2016 ◽  
Vol 306 ◽  
pp. 77-94 ◽  
Author(s):  
Matteo Aletti ◽  
Jean-Frédéric Gerbeau ◽  
Damiano Lombardi
Keyword(s):  
Arterial Flow ◽  
Structure Model ◽  
Fluid Structure

scholarly journals Analysis of a Coupled Fluid-Structure Model with Applications to Hemodynamics

2016 ◽  
Vol 54 (2) ◽  
pp. 994-1019 ◽  
Author(s):  
T. Chacón Rebollo ◽  
V. Girault ◽  
F. Murat ◽  
O. Pironneau
Keyword(s):  
Structure Model ◽  
Fluid Structure

scholarly journals COUPLED FLUID-STRUCTURE MODEL FOR MITRAL MECHANICAL HEART VALVES

ASAIO Journal ◽  
1996 ◽  
Vol 42 (2) ◽  
pp. 123
Author(s):  
V. B. Makhiiani ◽  
J. M. Siegel
Keyword(s):  
Heart Valves ◽  
Mechanical Heart Valves ◽  
Structure Model ◽  
Fluid Structure

Fracture propagation control in CO 2 pipelines: Validation of a coupled fluid–structure model

2016 ◽  
Vol 123 ◽  
pp. 192-212 ◽  
Author(s):  
E. Aursand ◽  
S. Dumoulin ◽  
M. Hammer ◽  
H.I. Lange ◽  
A. Morin ◽  
...  
Keyword(s):  
Fracture Propagation ◽  
Structure Model ◽  
Fluid Structure

Self-Excited Sloshing due to the Fluid Discharge Over a Flexible Cylindrical Weir

1999 ◽  
Vol 122 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Hiroshi Nagakura ◽  
Shigehiko Kaneko
Keyword(s):  
Analytical Model ◽  
The Self ◽  
Structure Model ◽  
Fast Breeder Reactor ◽  
Instability Mechanism ◽  
Dynamic Effects ◽  
Fluid Level ◽  
Fluid Structure ◽  
Cooling Circuit ◽  
Level Difference

This paper presents an analytical model for the self-excited sloshing due to the fluid discharge over a flexible weir, as observed in the cooling circuit of the French fast breeder reactor, Super-Phenix-1. To clarify the instability mechanism, we analyzed the case in which an annular reservoir was divided into an upstream and a downstream plenum by a flexible cylindrical weir. The kinematic and dynamic effects of the discharged fluid on downstream plenum sloshing are discussed in details. Calculations are presented for the cylindrical fluid-structure model with successively increasing fluid level difference between the upstream and downstream plenums, and the instability mechanism is examined. [S0094-9930(00)00901-X]

COUPLED FLUID-STRUCTURE MODEL FOR MITRAL MECHANICAL HEART VALVES

ASAIO Journal ◽  
1996 ◽  
Vol 42 (2) ◽  
pp. 123
Author(s):  
V. B. Makhijani ◽  
J. M. Siegel
Keyword(s):  
Heart Valves ◽  
Mechanical Heart Valves ◽  
Structure Model ◽  
Fluid Structure
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