28 th Turbomachinery Research Consortium Meeting Development of a Test Rig for Metal Mesh Foil Gas Bearing and Measurements of Structural Stiffness and Damping in the Metal Mesh Foil Bearing Luis San Andrés Tae-Ho Kim Thomas Abraham Chirathadam Alex Martinez ct title : Metal Mesh-Top Foil Gas Bearings for Oil-Free Turbomachin Test Rig for Prototype Demonstration
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28 th Turbomachinery Research Consortium Meeting Development of a Test Rig for Metal Mesh Foil Gas Bearing and Measurements of Structural Stiffness and.
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28th Turbomachinery Research Consortium Meeting
Development of a Test Rig for Metal Mesh Foil Gas Bearing and Measurements of Structural Stiffness and Damping in the
Metal Mesh Foil Bearing
Development of a Test Rig for Metal Mesh Foil Gas Bearing and Measurements of Structural Stiffness and Damping in the
Metal Mesh Foil Bearing
Luis San AndrésTae-Ho Kim
Thomas Abraham ChirathadamAlex Martinez
Project title : Metal Mesh-Top Foil Gas Bearings for Oil-Free Turbomachinery: Test Rig for Prototype Demonstration
TAMU past work on Metal Mesh Dampers
Zarzour and Vance (2000) J. Eng. Gas Turb. & Power, Vol. 122
Advantages of Metal Mesh Dampers over SFDsCapable of operating at low and high temperaturesNo changes in performance if soaked in oil
Al-Khateeb and Vance (2001) GT-2001-0247
Test metal mesh donut and squirrel cage( in parallel)MM damping not affected by modifying squirrel cage stiffness
Choudhry and Vance (2005) Proc. GT2005
Develop design equations, empirically based, to predict structural stiffness and viscous damping coefficient
METAL MESH DAMPERS proven to provide large amounts of damping. Inexpensive. Oil-free
Recent Patents: gas bearings & systems
A metal mesh donut is a cheap replacement to “porous foil”
‘Air foil bearing having a porous foil’Ref. Patent No. WO 2006/043736 A1
Turbocharger with hydrodynamic foil bearingsRef. Patent No. US7108488 B2
Foil JournalBearings
Thrust foilBearing
TRC Project: Tasks 07/08
Construction of Metal Mesh Foil Bearings -Assembly of top foil and metal mesh donut inside a cartridge
•Identification of structural force coefficients-Static load-deflection tests for structural stiffness -Dynamic load tests for stiffness and structural loss factor -Effects of frequency
•Construction of test rig for demonstration of MMFB Performance-Turbocharger (TC) driven system
Metal Mesh Foil Bearing (MMFB)
Molding of top foil (Heat treatment)
Top foil (An initial flat strip and a curved, heat treated foil) Top foil within Metal Mesh Donut
MMFB
Metal Mesh Foil Bearings Metal mesh donut and top foil assembled inside a
bearing cartridge. Hydrodynamic air film will develop between rotating shaft
and top foil.
Metal mesh resilient to temperature variations Damping from material hysteresis
Stiffness and viscous damping coefficients controlled by metal mesh material, size (thickness, L, D), and material compactness (density) ratio.
ApplicationReplace oil ring bearings in oil-free PV turbochargers
Metal Mesh Foil Bearings (+/-) No lubrication (oil-free). NO High
or Low temperature limits. Resilient structure with lots of
material damping. Simple construction ( in
comparison with other foil bearings)
Cost effective
Rotordynamic force coefficients unknown
Near absence of predictive models Damping NOT viscous. Modeling
difficulties
MMFB dimensions and specifications
Dimensions and Specifications ValuesBearing Cartridge outer diameter, DBo(mm) 58.15±0.02
Twin ball bearing turbocharger, Model T25, donated by Honeywell Turbo Technologies
Positioning table
Torque arm
Squirrel cage
(b) Front view(a) Right side view
Weight
Static load
TC driving system
Load cellEddy current sensor
Spring
Rotatingjournal
Static load applies upwards : using weights & pulleysArm and load cell to measure bearing torque measurement
Metal Mesh Foil Bearing Rotordynamic Test Rig
Positioning table: Max load 110N Max 3”X 3” travel in two directions Resolution of 1μm
- Supports squirrel cage- Provides motion in two
horizontal directions
Squirrel Cage: - Provides soft support to
MMFB- Maintains concentricity
(prevents tilting) of MMFB with test journal
Metal Mesh Foil Bearing Rotordynamic Test Rig
COST of positioning TABLE: $3631
Conclusions TC driven MMFB rotordynamic test rig under construction
Static and dynamic load tests on metal mesh bearings show large energy dissipation and (predictable) structural stiffness
MMFB stiffness decreases with amplitude of dynamic motion
Large MMFB structural loss factor ( ) at high frequencies
Predicted stiffness and equivalent viscous damping coefficients are in agreement with test coefficients: Test data validates design equations
TRC Proposal: Metal Mesh Foil Bearings for Oil-Free
Turbo-machinery : Rotordynamic performance
Complete construction of turbocharger driven MMFB test rig : squirrel cage, static loading device and torque measurement device
Conduct experiments on test rig Rotor lift off and touch down speeds, measurements of torque & load capacity, vibration and stability (if any)
Identification of dynamic force response Impact loads on test bearing + more measurements of
structural stiffness and loss factor
TA
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BUDGET FROM TRC FOR 2008/2009: Support for graduate student (20 h/week) x $ 1,600 x 12 months $ 22,008 + Fringe benefits (2.5%) and medical insurance ($ 164/month) Tuition three semesters ($ 3996x3) + Supplies for test rig($ 6004) $ 17,992 Total Cost: $ 40,000