Papers

Additive Manufacturing of Centrifugal Impellers for Solid Oxide Fuel Cell Anode Offgas Recycle Blowers

Córdova, J.L., “Additive Manufacturing of Centrifugal Impellers for Solid Oxide Fuel Cell Anode Offgas Recycle Blowers.” ASME Turbo Expo Technical Proceedings (2022). https://doi.org/10.1115/GT2022-83489 A form of laser powder bed fusion (LPBF) 3D printing has been used to manufacture the impellers of anode offgas recycle blowers (AORBs) for solid oxide fuel cell (SOFC) applications. The material […]

Development of Oil Free Centrifugal Blower As Enabling Technology for Solid Oxide Fuel Cell Anode Gas Recycling

Wooding, R., Lea, H., and Córdova, J.L., “Development of Oil Free Centrifugal BlowerAs Enabling Technology for Solid Oxide Fuel Cell Anode Gas Recycling.” ASME Turbo Expo Technical Conference Proceedings (2022). https://doi.org/10.1115/GT2022-82294 Broad commercialization of solid oxide fuel cells (SOFCs), requires anode offgas recycle blowers (AORB) that are specifically designed for handling the challenging operating conditions […]

Characterization of Properties of Laser Powder Bed Fusion 3D-Printed Inconel 718 for Centrifugal Turbomachinery Applications

Lea, H., Wooding, R., Kuhr, S., Rotella, J., and Córdova, J.L., “Characterization of Properties of Laser Powder Bed Fusion 3D-Printed Inconel 718 for Centrifugal Turbomachinery Applications.” ASME Turbo Expo Technical Conference Proceedings (2022). https://doi.org/10.1115/GT2022-83474 This paper presents the results of a comprehensive effort to characterize the properties of Inconel 718 produced by a form of […]

On the Integration of Hot Foil Bearings into Gas Turbine Engines: Theoretical Treatment

Heshmat, H. and Walton II, J.F., “On the Integration of Hot Foil Bearings into Gas Turbine Engines: Theoretical Treatment.” ASME Turbo Expo Technical Conference Proceedings (2019). http://doi.org/10.1115/GT2019-91710 To achieve high power density Gas Turbine Engines (GTEs), R&D efforts have strived to develop machines that spin faster and run hotter. One method to achieve that goal […]

Ultra-High Temperature Compliant Foil Bearings – The Journey to 870°C and Application in Gas Turbine Engines: Experiment

Heshmat, H., Walton II, J.F. and Nicholson, B.D., “Ultra-High Temperature Compliant Foil Bearings – The Journey to 870°C and Application in Gas Turbine Engines: Experiment.” ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition Proceedings (2018). http://doi.org/10.1115/GT2018-75555 In this paper, the authors present the results of recent developments demonstrating that ultra-high temperature compliant foil bearings […]

Technology Readiness of 5th and 6th Generation Compliant Foil Bearing for 10 MWE s-CO2 Turbomachinery Systems

Heshmat, H., Walton II, J.F. and Córdova, J.L., “Technology Readiness of 5th and 6th Generation Compliant Foil Bearing for 10 MWE s-CO2 Turbomachinery Systems.” Paper presented at the 6th International Supercritical CO2 Power Cycles Symposium, Pittsburgh, PA, March 2018. http://sco2symposium.com/www2/sco2/papers2018/components/072_Paper.pdf The availability of bearings capable of sustaining long life and maintenance‐free operation in the extreme […]

A Bladeless Turbocompressor Concept: Shear Driven Gas Compression with Deformable Structures—Part I Experimental Proof of Concept

Heshmat, H. and Walton, J.F., “A Bladeless Turbocompressor Concept: Shear Driven Gas Compression with Deformable Structures—Part I Experimental Proof of Concept.” ASME Power & Energy Conference Proceedings (2017). http://doi.org/10.1115/POWER-ICOPE2017-3374 A novel concept for shear flow driven gas compression that could enable next generation turbomachinery has been designed and experimentally demonstrated. In order to achieve this, […]

A Bladeless Turbocompressor Concept: Shear Driven Gas Compression with Deformable Structures—Part 2 Operating Principles and Theory

Heshmat, H., and Córdova, J.L., “A Bladeless Turbocompressor Concept: Shear Driven Gas Compression with Deformable Structures—Part 2 Operating Principles and Theory.” ASME Power & Energy Conference Proceedings (2017). http://doi.org/10.1115/POWER-ICOPE2017-3375 The theory underlying a novel method of gas compression driven by shear flow for next generation turbo-machinery is presented. The concept is based on the conversion […]

Development of a Ceramic Heat Exchanger for Application as Solid Oxide Fuel Cell Cathode Air Preheater

Córdova, J.L., and Heshmat, H., “Development of a Ceramic Heat Exchanger for Application as Solid Oxide Fuel Cell Cathode Air Preheater.” ASME Power & Energy Conference Proceedings (2016). http://doi.org/10.1115/POWER2016-59333 A ceramic heat exchanger with high effectiveness and low-pressure drop is being developed for application as a cathode air preheater for a Solid Oxide Fuel Cell […]

Lubricant Free Foil Bearings Pave Way to Highly Efficient and Reliable Flywheel Energy Storage System

Heshmat, H. and Walton II, J., “Lubricant Free Foil Bearings Pave Way to Highly Efficient and Reliable Flywheel Energy Storage System.” ASME Power & Energy Conference Proceedings (2016). http://doi.org/10.1115/ES2016-59350 Advanced compliant foil bearings capable of operating in low ambient pressures associated with soft vacuum are now paving the way to a new type of flywheel […]

Starved Hydrodynamic Gas Foil Bearings – Experiment, Micromechanical Phenomenon and Hypotheses

Heshmat, H. and Walton II, J.F., “Starved Hydrodynamic Gas Foil Bearings – Experiment, Micromechanical Phenomenon and Hypotheses.” STLE Tribology Frontiers Conference Proceedings, ASME. J. Tribology 138 no. 4 (March 2016). http://doi.org/10.1115/1.4032911 In this paper, a hypothesis for the operating tribological mechanisms and phenomena occurring in compliant surface gas foil bearings subjected to low ambient pressure […]

Ultra-High-Speed Micro-Milling of Aluminum Alloy

Jahanmir, S., Tomaszewski, M.J. and Heshmat, H., “Ultra-High-Speed Micro-Milling of Aluminum Alloy.” ASME International Mechanical Engineering Congress and Exposition Proceedings, 15 (2015). http://doi.org/10.1115/IMECE2015-50053 Small precision parts with miniaturized features are increasingly used in components such as sensors, micromedical devices, micro-fuel cells, and others. Mechanical micromachining processes, e.g., turning, drilling, milling and grinding are often used […]

Debris Tolerant Compliant Foil Bearings for High-Speed Turbomachines

Hunsberger, A., Walton II, J.F. and Heshmat, H., “Debris Tolerant Compliant Foil Bearings for High-Speed Turbomachines.” ASME Turbo Expo, Turbine Technical Conference and Expo Proceedings, 8 (2015). http://doi.org/10.1115/GT2015-43712 High-speed turbomachines such as air cycle machines (ACM), auxiliary power units (APU) and turbogenerators as used in aerospace systems operate in hot and harsh environments. Such operating […]

High Effectiveness, Low Pressure Drop Recuperator for High Speed and Power Oil-Free Turbogenerator

Córdova, J.L., Walton II, J.F., and Heshmat, H., “High Effectiveness, Low Pressure Drop Recuperator for High Speed and Power Oil-Free Turbogenerator.” ASME Turbo Expo, Turbine Technical Conference and Exposition Conference Proceedings, 8 (2015). http://doi.org/10-1115/GT2015-43718 Development of a compact radial recuperator prototype for a previously demonstrated 8 kW turboalternator has been completed. Its novel geometry has […]

Oil-Free 8 KW High-Speed and High Specific Power Turbogenerator

Heshmat, H., Walton II, J.F., and Hunsberger, A.Z.  “Oil-Free 8 KW High-Speed and High Specific Power Turbogenerator” GT2014-27306, Proceedings of the ASME Turbo Expo 2014: Power for Land, Sea and Air, June 16-20, 2014, Dusseldorf, Germany. In the paper the authors will present the design and preliminary test results for a high specific power (i.e., […]

Squeeze Film Damper Technology: Part I – Prediction of Finite Length Damper Performance

Lund, J. W., Smalley, A.J., Tecza, J.A., and Walton, J.F., “Squeeze Film Damper Technology: Part I – Prediction of Finite Length Damper Performance,” ASME International Gas Turbine and Aeroengine Congress and Exposition, Paper No. 83-GT-247.

Power Turbine Dynamics – An Evaluation of a Shear Mounted Elastomeric Damper

Walton, J.F., Zorzi, E. And Cunningham, R., “Power Turbine Dynamics – An Evaluation of a Shear Mounted Elastomeric Damper,” ASME International Gas Turbine and Aeroengine Congress and Exposition, Paper No. 83-GT-228. As an alternative to the more conventional squeeze-film bearing damper designs, a Viton-70 shear-mounted, elastomeric damper was built and tested in a T-55 power […]

Power Loss in High-Speed Micro Turbomachinery – An Experimental Study

Walton II, J.F., Heshmat, H. and Tomaszewski, M.J. “Power Loss in High-Speed Micro Turbomachinery – An Experimental Study” GT2012-69558, Proceedings of ASME Turbo Expo 2012: Power for Land, Sea and Air, June 11-15, 2012, Copenhagen, Denmark. In the paper the authors present the results of a study to investigate the windage and foil bearing losses […]

Evaluation of a New Coating for Application to Ramjet Engine

H. Heshmat, J. Walton, and S. Jahanmir, “Evaluation of a New Coating for Application to Ramjet Engine,” ASME-IGTI, Paper No. GT2012-68725, Copenhagen, Denmark, June 2012 In the present study, the adhesion and thermal characteristics of a new high temperature coating are evaluated. The new Korolon™ 1350A is applied by a conventional spray gun process at […]

Surface Integrity in Ultrahigh Speed Micromachining

S. Jahanmir, “Surface Integrity in Ultrahigh Speed Micromachining,” 1st CIRP Conference on Surface Integrity, Procedia Engineering, Bremen, Germany January 2012. A new ultrahigh speed micro-spindle was used for micro-milling and micro-grinding at speeds greater than 300,000 rpm. Micro-milling was performed on an aluminium alloy with micro-end-mills ranging in diameter from 50 to 300 μm. The dimensional accuracy […]

Load Capacity and Durability of H-DLC Coated Hydrodynamic Thrust Bearings

Jahanmir, S., Hunsberger, A. and Heshmat, H.  “Load Capacity and Durability of H-DLC Coated Hydrodynamic Thrust Bearings,” (July 2011) Journal of Tribology, Volume 133, pp. 031301-1 – 031301-10. Hydrogenated diamondlike carbon (H-DLC) coatings provide excellent wear resistance and low friction for bearing applications. However, the use of such coatings with aqueous lubricants could pose some […]

Tribological and Thermal Properties of a New Flexible Ceramic Coating

H. Heshmat, J. F. Walton and S. Jahanmir, “Tribological and Thermal Properties of a New Flexible Ceramic Coating,”  Proceedings of STLE Annual Meeting & Exhibition, May 15-19, 2011, Atlanta, GA. In the present study the tribological and thermal properties of a new environmental barrier coating are demonstrated for high temperature  applications.  The new Korolon™ 1350A, […]

Test and Simulation of a Mock Circulatory System with Starling Response for Evaluation of Ventricular Assist Devices

Design and Analysis of a High Power Density, Low Temperature Waste Heat Recovery System Using an Oil-Free Turboalternator

Walton II, J.F. Hunsberger, A.Z., and Heshmat, H. “Design and Analysis of a High Power Density, Low Temperature Waste Heat Recovery System Using an Oil-Free Turboalternator” IMECE 2010-40609, Proceedings of ASME IMECE, November 12-18, 2010, Vancouver, British Columbia, Canada. In this paper the authors will present the design and preliminary test results for a distributed […]

The Emergence of Compliant Foil Bearing and Seal Technologies in Support of 21st Century Compressors and Turbine Engines

Heshmat, H., Ren, Z., Hunsberger, A.Z., Walton II, J.F. and Jahanmir, S. “The Emergence of Compliant Foil Bearing and Seal Technologies in Support of 21st Century Compressors and Turbine Engines” IMECE2010-40598, Proceedings of ASME IMECE, November 12-18, 2010, Vancouver, British Columbia, Canada. For energy independence to become a reality, whether through the more effective use […]

Innovation is the Key to Sustaining Sustainability

Heshmat, H. “Innovation is the Key to Sustaining Sustainability” IMECE2010-37432, Proceedings of ASME IMECE, November 12-18, 2010, Vancouver, British Columbia, Canada, Volume 5, pp. 1259-1270. Economic survival and sustainability in the increasingly interconnected global community during the 21st century and beyond will require new and innovative technologies supported by subsequent continuous product improvements that minimize […]

On the Design of a Multi-Megawatt Oil-Free Centrifugal Compressor for Hydrogen Gas Transportation and Delivery – Operation Beyond Supercritical Speeds

Heshmat, H., Hunsberger, A.Z., Ren, Z., Jahanmir, S., Walton II, J.F. “On the Design of a Multi-Megawatt Oil-Free Centrifugal Compressor for Hydrogen Gas Transportation and Delivery – Operation Beyond Supercritical Speeds” IMECE2010-40575, Proceedings of ASME IMECE, November 12-18, 2010, Vancouver, British Columbia, Canada. Deployment of a safe, efficient hydrogen production and delivery infrastructure on a […]

Ultrahigh Speed Micromachining

S. Jahanmir, “Ultrahigh Speed Micromachining,” ASME Manufacturing Science and Engineering Conference Proceedings, Paper No. MSEC2010-34174, Erie PA, October 2010. A new ultrahigh speed micro-spindle has been developed for micromachining that can be used at rotational speeds as high as 500,000 rpm. Since conventional ball bearings or fluid lubricated journal bearings cannot be used at speeds […]

Structural Dynamic Design of a Rotating Hydrogen Co-Fired Multi-Fuel External Combustor

Heshmat, H., Walton II, J.F., Tomaszewski, M.J. and Potgieter, D.J.  “Structural Dynamic Design of a Rotating Hydrogen Co-Fired Multi-Fuel External Combustor” Proceedings of ASME Turbo Expo 2010: Power for Land, Sea and Air, June 14-18, 2010, Glasgow, UK.

On the Development of an Oil-Free, High-Speed and High-Temperature Turboalternator

Heshmat, H. and Walton II, J.F.  “On the Development of an Oil-Free, High-Speed and High-Temperature Turboalternator” GT2010-22852, Proceedings of ASME Turbo Expo 2010: Power for Land, Sea and Air, June 14-18, 2010, Glasgow, UK, Volume 5, pp. 425-432. In the paper the authors will present the design and preliminary test results for a distributed electric […]

Oil-Free Renewable Energy Turbine Generator Systems

Walton, J.F., “Oil-Free Renewable Energy Turbine Generator Systems”; Presented at The IAPG Mechanical & Electrical Systems Working Groups Meeting, Golden CO, May 3-5, 2010

An Advanced High Efficiency Modular, Flywheel Energy Storage System

Heshmat, H. and Walton, J.F., “An Advanced High Efficiency Modular, Flywheel Energy Storage System,” Presented at The IAPG Mechanical & Electrical Systems Working Groups Meeting, Golden CO May 3-5, 2010 In the paper the author will present the design and operating test results for a novel energy storage flywheel system. Proof of concept testing of […]

Pre-Clinical Evaluation of MITIHEART® LVAD

A. Z. Hunsberger, S. Jahanmir, Z. Ren, L. Montessano, “Pre-Clinical Evaluation of MITIHEART® LVAD,” ASAIO Journal, 56 (2010) 135.

Design and Evaluation of an Ultrahigh Speed Micro-Machining Spindle

S. Jahanmir, H. Z. Ren, H. Heshmat, and M. Tomaszweski, “Design and Evaluation of an Ultrahigh Speed Micro-Machining Spindle,” Machining Science and Technology, 14 (2010) 224-243. A new ultrahigh speed micro-spindle has been developed for micro-milling that can be used at rotational speeds approaching 500,000 rpm. Since conventional ball bearings or fluid lubricated journal bearings cannot […]

Ultrahigh Speed Micro-Grinding of Dental Ceramics

S. Jahanmir, “Ultrahigh Speed Micro-Grinding of Dental Ceramics,” Machining Science and Technology, 14 (2010) 430-440. Theoretical models and experimental results on machining of industrial ceramics have shown that machining at high speeds reduces the grit depths of cut, thus reducing the contact forces and resulting in a reduced possibility of detrimental chipping and subsurface machining […]

Design Analysis and Performance Assessment of Hybrid Magnetic Bearings for a Rotary Centrifugal Blood Pump

Ren, Z., Jahanmir, S., Heshmat, H., Hunsberger, A.Z. and Walton II, J.F.  “Design Analysis and Performance Assessment of Hybrid Magnetic Bearings for a Rotary Centrifugal Blood Pump,” (July/August 2009) ASAIO Journal, Volume 55, Issue 4, pp. 340-347. A hybrid magnetic bearing system was designed for a rotary centrifugal blood pump being developed to provide long-term […]

An Advanced High-Efficiency Power Generation and Thermal Management System

Walton, J.F., “An Advanced High-Efficiency Power Generation and Thermal Management System”; Presented at the IAPG Mechanical & Electrical Systems Working Groups Meeting-NAVSEA-SSES Philadelphia – May 4-8, 2009

Status of the Magnetically levitated MiTiHeart LVAD

A. Z. Hunsberger, S. Jahanmir, Z. Ren, H. Heshmat, M. J. Tomaszewski, J. F. Walton, “Status of the Magnetically levitated MiTiHeart LVAD,” ASAIO Journal, 55 (2009) 135.

Assessment of Tribological Coatings for Foil Bearing Applications

Jahanmir, S., Heshmat, H. and Heshmat, C.A.  “Assessment of Tribological Coatings for Foil Bearing Applications,” (2009) STLE Tribology Transactions, Volume 52, No. 2, pp. 231-242. A critical component in oil-free gas foil bearings is the tribological coating system that must be used on the journal/runner and the foil pads to ensure reliable operation during transient […]

Evaluation of DLC Coatings for High-Temperature Foil Bearing Applications

Jahanmir, S., Heshmat, H. and Heshmat, C.A.  “Evaluation of DLC Coatings for High-Temperature Foil Bearing Applications,”  (2009) Journal of Tribology, Volume 131, No. 1, pp. 011301-1 – 011301-11. Diamond like carbon (DLC) coatings, particularly in the hydrogenated form, provide extremely low coefficients of friction in concentrated contacts. The objective of this investigation was to evaluate […]

Design of a Small Centrifugal Blood Pump with Magnetic Bearings

Jahanmir, S., Hunsberger, A.Z., Ren, Z., Heshmat, H., Heshmat, C.A., Tomaszewski, M.J. and Walton II, J.F.  “Design of a Small Centrifugal Blood Pump with Magnetic Bearings,”  (2009) Artificial Organs, Volume 33, No. 9, pp. 714-726. Design of a blood pump with a magnetically levitated rotor requires rigorous evaluation of the magnetic bearing and motor requirements […]

Innovative High-Temperature Compliant Surface Foil Face Seal Development

Heshmat, H. and Walton II, J.F.  “Innovative High-Temperature Compliant Surface Foil Face Seal Development,” AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 21-23, 2008 Hartford, Connecticut. An innovative compliant surface foil face seal being developed for aerospace applications will be described and discussed in this paper.  Due to the requirements of gas turbine applications, this compliant surface face […]

Performance Assessment of a Hybrid Magnetic Bearing System for Rotary Centrifugal Blood Pump

Ren, Z., Hunsberger, A.Z., Jahanmir, S., Heshmat, H. and Walton II, J.F.  “Performance Assessment of a Hybrid Magnetic Bearing System for Rotary Centrifugal Blood Pump,” 54th Annual ASAIO Conference, June 19-21, 2008, San Francisco, California. The performance of a proposed hybrid magnetic bearing system for a rotary blood pump is experimentally evaluated. The hybrid magnetic […]

A Compact and Efficient 12-Kw Compressor for Automotive Fuel Cell Applications

Walton, J.F., Heshmat, H.  “A Compact and Efficient 12-Kw Compressor for Automotive Fuel Cell Applications,” ASME 6th International Fuel Cell Science, Engineering and Technology Conference, Denver, Colorado, June 16-18, 2008. A novel concept air handling unit for Fuel cell’s infrastructure which serves as the foundational components has been developed and prototype unit have been tested […]

Development of an 80 Kw Oil-Free, High Speed Blower for Fuel Cell Applications

Heshmat, H., Walton II, J.F.  “Development of an 80 Kw Oil-Free, High Speed Blower for Fuel Cell Applications,” ASME 6th International Fuel Cell Science, Engineering & Technology, Conference, Denver, CO, June 16-18, 2008. This paper presents the design and development methodology used to develop an air blower on an integral motor rotor /impeller system, operating […]

Design, Development and Test of a 30 KW Oil-Free, Turboalternator

Heshmat, H., Walton II, J.F. and Tomaszewski, M.J.  “Design, Development and Test of a 30 KW Oil-Free, Turboalternator,” GT208-51514, Proceedings of the 2008 ASME Turbo Expo-Power for Land, Sea & Air, June 9-13, 2008, Berlin, Germany. This paper describes the design procedures and testing program used in the development of a 30 kW single shaft […]

Performance Characterization of MiTiHeart Rotary Centrifugal LVAD with Magnetic Suspension

S. Jahanmir, A. Z. Hunsberger, H. Heshmat, M. J. Tomaszewski, J. F. Walton, W. J. Weiss, B. Lukic, W. E. Pae, and C. M. Zappanta, T. Z. Khalapyan, “Performance Characterization of MiTiHeart Rotary Centrifugal LVAD with Magnetic Suspension,” Artificial Organs, 32 (2008) 366-375 The MiTiHeart (MiTiHeart Corporation, Gaithersburg, MD, USA) left ventricular assist device (LVAD), […]

Characterization of the New MiTiHeart LVAD Prototype

S. Jahanmir, A. Z. Hunsberger, Z. Ren, H. Heshmat, M. J. Tomaszewski, J. F. Walton, “Characterization of the New MiTiHeart LVAD Prototype,” Artificial Organs, 32 (2008) A1.

Performance Characterization of a Rotary Centrifugal LVAD with Magnetic Suspension

Jahanmir, S., Hunsberger, A.Z., Heshmat, H., Tomaszewski, M.J., Walton, J.F., Weiss, W.J., Lukic, B., Paw, W.E., Zapanta, C.M. and Khalapyan, T.Z.  “Performance Characterization of a Rotary Centrifugal LVAD with Magnetic Suspension,” (May 2008) Artificial Organs, Blackwell Publishing Limited, Volume 32 (5), pp. 366-375. The MiTiHeart® LVAD, a third generation blood pump, is being developed for […]

Status of the Magnetically levitated MiTiHeart LVAD

S. Jahanmir, Z. Ren, A. Z. Hunsberger, H. Heshmat, M. J. Tomaszewski, J. F. Walton, “Status of the Magnetically levitated MiTiHeart LVAD,” ASAIO Journal, 54 (2008) 22A.

Evaluation of DLC Coatings for Foil Bearing Applications

Jahanmir, S., Heshmat, H., Heshmat, C.A., Eryilmaz, O. and Erdemir, A.  “Evaluation of DLC Coatings for Foil Bearing Applications,” IJTC2007-44035, Proceedings of ASME/STLE International Joint Tribology Conference, IJTC 2007, Part A, pp. 5-7, October 22-24, 2007, San Diego, California. A critical component in oil-free air foil bearings is the tribological coating system that must be […]

Hybrid Magnetic Bearings for a Centrifugal Blood Pump

Ren, Z., Jahanmir, S., Heshmat, H. and Walton II, J.F.  “Hybrid Magnetic Bearings for a Centrifugal Blood Pump,” IJTC2007-44199, Proceedings of ASME/STLE International Joint Tribology Conference, IJCT2007, Part B, pp. 997-999, October 22-24, 2007, San Diego, California. A hybrid passive/active magnetic bearing system was designed for a rotary centrifugal blood pump being developed for long-term […]

Performance Evaluation of Half-Wetted Hydrodynamic Bearings with DLC Coated Surfaces

Hunsberger, A.Z., Jahanmir, S., Heshmat, H., Eryilmaz, O. and Erdemir, A.  “Performance Evaluation of Half-Wetted Hydrodynamic Bearings with DLC Coated Surfaces,” IJTC2007-44207, Proceedings of ASME/STLE International Joint Tribology Conference, IJCT2007, Part A, pp. 241-243, October 22-24, 2007, San Diego, California, (2007) ASAIO Journal, 53, 31A. In conventional liquid lubrication it is assumed that surfaces are […]

Design and Performance Evaluation of a Hybrid Magnetic Bearing for a Rotary Blood Pump

Z. Ren, S. Jahanmir, A. Hunsberger, H. Heshmat, and J. Walton “Design and Performance Evaluation of a Hybrid Magnetic Bearing for a Rotary Blood Pump,” Proceedings of International Joint Tribology Conference, San Diego, CA, Oct 22-26, 2007, Paper No. IJTC20076-44199, ASME, New York.

An Oil-Free Motorized Turbocompressor For Fuel Cells

Walton, J.F., II, Heshmat, H., and Tomaszewski, M.J., “An Oil-Free Motorized Turbocompressor For Fuel Cells,” Presented at 5th Fuel Cell Science, Engineering & Technology Conference, Jun 18 2007 – Jun 20 2007, Brooklyn, New York, United States.

In Vitro Characterization of the Redesigned MiTiHeart LVAD

A. Z. Hunsberger, Z. Ren, S. Jahanmir, H. Heshmat, M. J. Tomaszewski, J. F. Walton, “In Vitro Characterization of the Redesigned MiTiHeart LVAD,” ASAIO Journal, 53 (2007) 32A.

On the Coupling of Foil Bearing Supported Rotors: Part 1 – Analysis

Heshmat, H., Walton II, J.F. and Heshmat, C.A.  “On the Coupling of Foil Bearing Supported Rotors: Part 1 – Analysis,” ASME Paper GT2007-27821, Proceedings of the ASME Turbo Expo: Power for Land, Sea & Air, Volume 5, pp. 943-950, May 2007, Montreal, Canada. The expanded application of high-speed rotor systems operating on compliant foil bearings […]

On the Coupling of Foil Bearing Supported Rotors: Part 2 – Experiment

Tomaszewski, M., Walton II, J.F. and Heshmat, H.  “On the Coupling of Foil Bearing Supported Rotors: Part 2 – Experiment,” ASME Paper GT2007-27825, Proceedings of the ASME Turbo Expo: Power for Land, Sea & Air, Volume 5, pp. 951-960, May 2007, Montreal, Canada.  The expanded application of high-speed rotor systems operating on compliant foil bearings […]

Coatings for High Temperature Foil Bearings

Heshmat, H., Jahanmir, S. and Walton II, J.F.  “Coatings for High Temperature Foil Bearings,” ASME Paper GT2007-27975, Proceedings of the ASME Turbo Expo: Power for Land, Sea & Air, Volume 5, pp. 971-976, May 2007, Montreal, Canada. High operating speeds and temperatures required for advanced turbomachinery necessitate the development of bearings capable of continuous operation […]

Evaluation of Coatings for a Large Hybrid Foil/Magnetic Bearing

Heshmat, H. and Jahanmir, S.  “Evaluation of Coatings for a Large Hybrid Foil/Magnetic Bearing,” ASME Paper IJTC2006-12328, International Joint Tribology Conference, October 23-25, 2006, San Antonio, Texas, (2006). High operating speeds and temperatures required for advanced turbomachinery necessitate the development of bearings capable of continuous operation between 3 and 4 million DN at temperatures up […]

Small Gas Turbine Engine Operating with High-Temperature Foil Bearings

Hooshang, H., Tomaszewski, M. and Walton II, J.F.  “Small Gas Turbine Engine Operating with High-Temperature Foil Bearings,” ASME Paper GT2006-90791, ASME Power for Land, Sea and Air, May 2006, Barcelona, Spain, (2006) Proceedings of the ASME Turbo Expo, Volume 5 (PART A), pp. 387-393. A 134 Newton thrust class, 120,000 rpm turbojet was redesigned to […]

On the Development of an Oil-Free Electric Turbocharger for Fuel Cells

Walton II, J.F., Tomaszewski, M.J., Heshmat, C.A. and Heshmat, H.  “On the Development of an Oil-Free Electric Turbocharger for Fuel Cells,” ASME Paper GT2006-90796, ASME Power for Land, Sea and Air, May 2006, Barcelona, Spain, (2006) Proceedings of the ASME Turbo Expo, Volume 5 (PART A), pp. 395-400. Proton Exchange Membrane, fuel cells intended for […]

Small Gas Turbine Engine Operating With High-Temperature Foil Bearings

Heshmat, H., Tomaszewski, M., and Walton J. F.,”Small Gas Turbine Engine Operating With High-Temperature Foil Bearings,” Paper GT2006-90791, presented at the International Gas Turbine Institute Turbo Expo Conference, Barcelona, Spain, May 2006

On The Development Of An Oil-Free Electric Turbocharger For Fuel Cells

Walton, J.F., II, Tomaszewski, M.J., Heshmat, C.S. and Heshmat, H. “On The Development Of An Oil-Free Electric Turbocharger For Fuel Cells,” Paper GT2006-90796, presented at the International Gas Turbine Institute Turbo Expo Conference, Barcelona, Spain, May 2006.

Design of a Small Centrifugal Blood Pump with Hybrid Magnetic Bearings

S. Jahanmir, H. Heshmat, Z. Ren, A. Z. Hunsberger, C. A. Heshmat, M. J. Tomaszewski, J. F. Walton, “Design of a Small Centrifugal Blood Pump with Hybrid Magnetic Bearings,” ASAIO Journal, 52 (2006) 54A. Design of a blood pump with a magnetically levitated rotor requires rigorous evaluation of the magnetic bearing and motor requirements and analysis […]

Prediction of Hydrodynamic Bearing Performance for Cardiac Assist Devices

H. Heshmat, A. Z. Hunsberger, S. Jahanmir, M. J. Tomaszewski, J. F. Walton, “Prediction of Hydrodynamic Bearing Performance for Cardiac Assist Devices,” ASAIO Journal, 52 (2006) 51A Development of a reliable and efficient bearing system is one of the most critical challenges of long-term rotary mechanical circulatory support. Non-contacting hydrodynamic bearings offer superior performance to contact […]

A Turbojet Engine Demonstration with Air Foil Bearing

Heshmat, Hooshang, Walton, James F. II, Tomaszewski, Michael J., Cruzen, G. Scott and Rabe, Lavern, “A Turbojet Engine Demonstration with Air Foil Bearing,” Presented at the UVS Tech 2003, Royal Military Academy, Brussels, Belgium, December 3-5, 2003

Low-Friction Wear Resistant Coatings for High-Temperature Foil Bearings

Heshmat, H., Hryniewicz, P., Walton II, J.F., Willis, J.P. and Jahanmir, S.  “Low-Friction Wear Resistant Coatings for High-Temperature Foil Bearings,” ASME Paper WTC2005-63684, ASME WTC 2005, September 12-16, 2005, Washington D.C., (2005) Proceedings of the World Tribology Congress III – 2005, pp. 399-400. Compliant foil bearings offer many advantages over rolling element bearings in high-speed […]

Major Breakthrough in Load Capacity, Speed and Operating Temperature of Foil Thrust Bearings

Heshmat, H.  “Major Breakthrough in Load Capacity, Speed and Operating Temperature of Foil Thrust Bearings,” ASME Paper WTC2005-63712, ASME WTC 2005, September 12-16, 2005, Washington D.C., (2005) Proceedings of the World Tribology Congress III – 2005, pp. 111-112. This paper describes major breakthroughs in foil thrust bearings achieving a thrust load capacity in excess of […]

Foil Bearings Make Oil-Free Turbocharger Possible

Heshmat, H., Heshmat, C., Valco, M.J., Radil, K.C. and Della Corte, C.  “Foil Bearings Make Oil-Free Turbocharger Possible,” ASME Paper WTC2005-63724, ASME WTC 2005, September 12-16, 2005, Washington D.C., (2005) Proceedings of the World Tribology Congress III – 2005, pp. 113-114. This paper describes an oil-free, 150 Hp turbocharger that was successfully operated with compliant […]

Turbojet Engine Demonstration with a High-Temperature, High-Speed Tribometer with Complex Motion

Heshmat, H., Tomaszewski, M.J., Walton II, J.F. and Jahanmir, S.  “High-Temperature, High-Speed Tribometer with Complex Motion,” ASME Paper WTC2005-63685, ASME WTC 2005, September 12-16, 2005, Washington D.C., (2005) Proceedings of the World Tribology Congress III – 2005, pp. 879-880. Complex motions and wide variations in relative surface velocities are likely to be experienced in mechanical […]

Low-friction Wear Resistant Coatings for High-Temperature Foil Bearings

Heshmat, H., Hryniewicz, P., Walton J. F. Willis, J.P., and Jahanmir, S., “Low-friction Wear Resistant Coatings for High-Temperature Foil Bearings,” WTC2005-63684, Accepted for presentation at World Tribology Congress September 12-16, 2005, Washington, D. C.

Magnetically Suspended Rotary Blood Pump

Heshmat, H., Walton J. F., Tomaszewski, M., and Jahanmir, S., “Magnetically Suspended Rotary Blood Pump,” WTC2005-63681, Accepted for presentation at World Tribology Congress September 12-16, 2005, Washington, D. C.

Demonstration of a Turbojet Engine Using an Air Foil Bearing

Heshmat, H., Walton J. F. and Tomaszewski, M., “Demonstration of a Turbojet Engine Using an Air Foil Bearing,”Paper GT2005-68404 presented at ASME Turbo Expo, Land, Sea and Air, International Gas Turbine Conference, Reno, NV June 6-9, 2005 Selected for ASME 2005 IGTI Vehicular & Small Turbomachines Committee Best Paper Award

In Vivo Performance of a Magnetically Suspended Rotary Blood Pump Prototype

S. Jahanmir, J. P. Willis, J. F. Walton, H. Heshmat, W. J. Weiss, B. Lukic, W. E. Pae, and G. A. Prophet, “In Vivo Performance of a Magnetically Suspended Rotary Blood Pump Prototype,” ASAIO Journal, 50 (2004) 134.

Status of Magnetically Suspended MiTiHeart LVAD

Jahanmir S, Heshmat H, Tomaszewski M., Walton JF, Hunsberger AZ,Weiss WJ, Lukic B, Pae WE, Zapanta CM and Khalapyan TZ, “Status of Magnetically Suspended MiTiHeart LVAD,”, Presented at ASIAO Conference, Wasington, DC, June 2005 The MiTiHeart® LVAD is a non-pulsatile rotary blood pump that uses a hybrid passive/active magnetic bearing support system and exhibits low-hemolysis, […]

Wear Mechanisms of Glass-Infiltrated Alumina Sliding Against Alumina in Water

M. Kalin, S. Jahanmir, and G. Drazic, “Wear Mechanisms of Glass-Infiltrated Alumina Sliding Against Alumina in Water,” Journal of the American Ceramic Society, 88 (2005) 346-352. Glass-infiltrated alumina is now commonly used as a core material in dental restorations. If the veneer layer, which covers the core, is broken or damaged through use, a direct […]

Magnetically Suspended Rotary Blood Pump

Heshmat, H., Walton II, J.F., Tomaszewski, M.J. and Jahanmir, S.  “Magnetically Suspended Rotary Blood Pump,” ASME Paper WTC2005-63681, ASME WTC 2005, September 12-16, 2005, Washington D.C., (2005) Proceedings of the World Tribology Congress III – 2005, pp. 611-612. MiTiHeartTM LVAD is a rotary centrifugal blood pump with a hybrid passive/active magnetic bearing support system. It […]

Low-Friction Wear-Resistant Coatings for High-Temperature Foil Bearings

Heshmat, H., Hryniewicz, P., Walton II, J.F., Willis, J.P., Jahanmir, S. and DellaCorte, C.  “Low-Friction Wear-Resistant Coatings for High-Temperature Foil Bearings,” (2005-2006) Tribology International, Volume 38, Issue 11-12, pp. 1059-1075. Compliant foil bearings offer many advantages over rolling element bearings in high-speed and high-temperature applications. However, implementation of foil bearings in these applications requires development […]

On the nature of Machining Cracks in Ground Ceramics: Part I, SRBSN Strength and Fractographic Analysis

G. D. Quinn, L. K. Ives, and S. Jahanmir, “On the nature of Machining Cracks in Ground Ceramics: Part I, SRBSN Strength and Fractographic Analysis,” Machining Science and Technology, 9 (2005) 169-210. Machining cracks in ground sintered reaction-bonded silicon nitride (SRBSN) rods and bars were analyzed by fractographic techniques. Grinding flaw sizes were as small […]

On the nature of Machining Cracks in Ground Ceramics: Part II, Comparison to Other Silicon Nitrides and Damage Maps

G. D. Quinn, L. K. Ives, and S. Jahanmir, “On the nature of Machining Cracks in Ground Ceramics: Part II, Comparison to Other Silicon Nitrides and Damage Maps,” Machining Science and Technology, 9 (2005) 211-237. The size and severity of grinding machining cracks in a sintered reaction bonded silicon nitride from part I are compared […]

Testing of a Small Turbocharger/Turbojet Sized Simulator Rotor Supported on Foil Bearings

Walton II, J.F., Heshmat, H. and Tomaszewski, M.J. “Testing of a Small Turbocharger/Turbojet Sized Simulator Rotor Supported on Foil Bearings,” ASME Paper GT2004-53647, ASME Turbo Expo 2004, Power for Land, Sea & Air, June 14-17, 2004, Vienna, (2004) Proceedings of the ASME Turbo Expo 2004, Volume 6, pp. 67-73 and published in the ASME Journal […]

Advancements in the Structural Stiffness and Damping of a Large Compliant Foil Journal Bearing – An Experimental Study

Salehi, M., Heshmat, H. and Walton II, J.F. “Advancements in the Structural Stiffness and Damping of a Large Compliant Foil Journal Bearing – An Experimental Study,” Paper GT2004-53860, 2004 ASME Turbo Expo: Power for Land, Sea & Air, June 14-17, 2004, Vienna, (2004) Proceedings of the ASME Turbo Expo 2004, Volume 6, pp. 725-733, (2007) […]

Operation of a Mesoscopic Gas Turbine Simulator at Speeds in Excess of 700,000 rpm on Foil Bearings

Salehi, M., Heshmat, H., Walton II, J.F. and Tomaszewski, M.J. “Operation of a Mesoscopic Gas Turbine Simulator at Speeds in Excess of 700,000 rpm on Foil Bearings,” ASME Paper GT2004-53870, 2004 ASME Turbo Expo: Power for Land, Sea & Air, June 14-17, 2004, Vienna, (2004) Proceedings of the ASME Turbo Expo 2004, Volume 6, pp. […]

Status of Magnetically Suspended MiTiHeart LVAD

S. Jahanmir, J. P. Willis, M. Tomaszewski, P. Hryniewicz, and H. Heshmat, “Status of Magnetically Suspended MiTiHeart LVAD,” ASAIO Journal, 50 (2004) 111.

Testing of a Small Turbocharger/Turbojet Sized Simulator Rotor Supported on Foil Bearings

Walton J. F., Heshmat, H., and Tomaszewski, M., “Testing of a Small Turbocharger/Turbojet Sized Simulator Rotor Supported on Foil Bearings’” Paper GT2004-53647 presented at ASME Turbo Expo, Land, Sea and Air, International Gas Turbine Conference, Vienna, Austria June 2004

Operation of a Mesoscopic Gas Turbine Simulator at Speeds in Excess of 700,000 rpm on Foil Bearings

Salehi, M., Heshmat, H., Walton J. F., “Operation of a Mesoscopic Gas Turbine Simulator at Speeds in Excess of 700,000 rpm on Foil Bearings,” Paper GT2004-53870 presented at ASME Turbo Expo, Land, Sea and Air, International Gas Turbine Conference, Vienna, Austria June 2004, accepted for journal publication.

Advancements In The Structural Stiffness and Damping Of A Large Compliant Foil Journal Bearing: An Experimental Study

Salehi, M., Heshmat, H., Walton J. F., “Advancements In The Structural Stiffness and Damping Of A Large Compliant Foil Journal Bearing: An Experimental Study,” Paper GT2004-53860 presented at ASME Turbo Expo, Land, Sea and Air, International Gas Turbine Conference, Vienna, Austria June 2004, Accepted for Journal publication

Tribological Behavior of Ceramics at High Sliding Speeds in Steam

Heshmat, H. and Jahanmir, S.  “Tribological Behavior of Ceramics at High Sliding Speeds in Steam,” STLE, May 2004, (2004) Tribology Letters, Volume 17 (3), pp. 359-366. Three sets of tests were conducted using a pin-on-disk tribometer to determine the tribological behavior of ceramics at high sliding speeds in steam. In the first set, the speed […]

Advancing the Load Capacity and Operating Temperature of Foil Thrust Bearings

Heshmat, H. and Hryniewicz, Ph.D.  “Advancing the Load Capacity and Operating Temperature of Foil Thrust Bearings” (2004) Bulletin of the Polish Society of Tribology (Tribologia), Volume 35 (3), pp.145-157. Compliant foil bearings offer many advantages over rolling element bearings in high-speed and high-temperature applications.  Foil bearings are stable at high speed and high-temperature applications.  Foil […]

Experimental Investigation of Mechanisms of Silicon Chemical Mechanical Polishing

E. Estragnat, G. Tang, H. Liang, S. Jahanmir, P. Pei, J. M. Martin, “Experimental Investigation of Mechanisms of Silicon Chemical Mechanical Polishing,” J Electronic Materials, 33 (2004) 334-339. In this research, we conducted a series of experiments to investigate the mechanisms of chemical mechanical polishing (CMP) of silicon. Experimental approaches include tribological tests of frictional […]

Effects of Fluids on the Simulated Clinical Dental Machining of a Micaceous Glass Ceramic

L. Yin, L. K. Ives, and S. Jahanmir, “Effects of Fluids on the Simulated Clinical Dental Machining of a Micaceous Glass Ceramic,” Journal of the American Ceramic Society, 87 (2004) 173-175. L. Yin, S. Jahanmir, and L.K. Ives, “Abrasive Machining of Porcelain and Zirconia with a Dental Handpiece,” Wear, 255 (2003) 975-989.  The machining characteristics […]

Water Lubrication of Silicon Nitride in Sliding

S. Jahanmir, Y. Ozmen, and L. K. Ives, “Water Lubrication of Silicon Nitride in Sliding,” Tribology Letters, 17 (2004) 409-417. Several studies have shown that the coefficient of friction of self-mated silicon nitride in water decreases from an initially high value to about 0.002 after a certain run-in period. Since the worn surfaces become extremely […]

A Turbojet Engine Demonstration with Air Foil Bearing

Heshmat, H., Walton II, J.F., Tomaszewski, M., Cruzen, G.S. and Rabe, L.  “A Turbojet Engine Demonstration with Air Foil Bearing,” UVS Tech 2003, Royal Military Academy, Brussels, Belgium, December 3-5, 2003. A test of the WJ24-8 turbojet engine, the main propulsion engine for the BQM-74 target drone, was recently conducted that demonstrated successful operation of […]

A 700,000 rpm Feasibility Demonstration for Mesoscopic Scale Gas Turbine Engines

Salehi, M., Tomaszewski, M.J., Walton II, J.F. and Heshmat, H.  “A 700,000 rpm Feasibility Demonstration for Mesoscopic Scale Gas Turbine Engines,” UVS Tech 2004, Royal Military Academy, Brussels, Belgium, December 3-5, 2003. A new class of miniature weapons and war fighting systems is being developed that requires a mesoscopic sized turbojet engine for power and […]

A 700,000 rpm Feasibility Demonstration for Mesoscopic Scale Gas Turbine Engines

Salehi, M., Tomaszewski, Michael J., Walton James F. II, Heshmat, Hooshang, “A 700,000 rpm Feasibility Demonstration for Mesoscopic Scale Gas Turbine Engines,” Presented at the UVS Tech 2003, Royal Military Academy, Brussels, Belgium, December 3-5, 2003

Experimental Investigation of 150mm Diameter Large Hybrid Foil/Magnetic Bearing

Heshmat, H. and Xu, David S.  “Experimental Investigation of 150mm Diameter Large Hybrid Foil/Magnetic Bearing,” Paper IGTC2003Tokyo-TS-017, 2003 International Gas Turbine Congress, Tokyo, Japan, November 2-7, 2003. By combining both compliant foil bearing (CFB) and active magnetic bearing (AMB) advantages, the hybrid foil/magnetic bearing (HFMB) can obtain high load capacity at all speeds. A brief […]

In Vivo Study of an LVAD Prototype with a Hybrid Magnetic Bearing

J. P. Willis, D. H. Locke, P. Hryniewicz, S. Jahanmir, and H. Heshmat, “In Vivo Study of an LVAD Prototype with a Hybrid Magnetic Bearing,” ASAIO Journal, 49 (2003) 176.  A second-generation prototype of a high efficiency, non-pulsatile rotary blood pump was developed for use as a left ventricular assist device (LVAD). The LVAD pump […]

New-Generation Development Rigs for Testing High-Speed Air-Lubricated Thrust Bearings

Hryniewicz, P., Locke, D.H. and Heshmat, H. “New-Generation Development Rigs for Testing High-Speed Air-Lubricated Thrust Bearings,” ASME 58th Annual Meeting, New York City, April 28–May 1, 2003, (2003) Tribology Transactions, Volume 46 (4), pp. 556-559. A major advantage of compliant air-lubricated bearings is their excellent performance at very high rotational speeds and operating temperatures.  Successful […]

The Role of High Performance Foil Bearings in Advanced, Oil-Free, High-Speed Motor Driven Compressors

Walton II, J.F., Tomaszewski, M.J. and Heshmat, H. “The Role of High Performance Foil Bearings in Advanced, Oil-Free, High-Speed Motor Driven Compressors,” ASME Paper Fuel Cell 2003-1747, 1st International Conference on Fuel Cell Science, Engineering and Technology, April 21-23, 2003, Rochester, New York, (2003) Fuel Cell Science, Engineering and Technology, pp. 411-417 The demand for […]