Professor of Mechanical Engineering

Education    

Technion, Israel Institute of Technology, DSc 1972  
Technion, Israel Institute of Technology, MS 1977   
Technion, Israel Institute of Technology, BS.1961

Current Research Interests    

Dr. Harnoy is investigating all aspects of bearings and bearing lubrication in machinery. In particular, design, heat transfer, material selection, testing and analysis of hydrodynamic, hydrostatic and rolling-element bearings as well as unique designs such as hybrid bearings.   Design and development testing machines for dynamic friction, tribology of bearing materials and lubricants. He is conducting research in modeling and measurement of dynamic friction in bearings. Dynamic friction models are used for friction compensation for enhancing the precision of motion in control systems. This work includes simulation and measurements of dynamic friction effects such as stick-slip friction and friction induced vibrations. In addition, research is conducted in flow behavior of viscoelastic fluids such as multigrade oils, as well as synthetic lubricants.  

Recent activity is the investigation of the performance, design and material properties of orthopedic joint implants.

Books   

Avraham Harnoy, Bearing Design in Machinery, Engineering Tribology and Lubrication, Marcel Dekker Inc., ISBN: 0-8247-0703-6, 628 pgs., 2003. Selected Publications  

Amin J., Friedland B. and Harnoy A. “Implementation of a Friction Estimation and Compensation Technique” IEEE Control Systems, Vol. 17, No. 4, pp.71-76, 1997   

A. Harnoy, “Simulation of stick-slip in control systems,” Tribology Transactions, vol. 40, pp. 360-366, 1996.   

A. Harnoy and M. M. Khonsari, “Hydro-Roll: A Novel Bearing Design With Superior Thermal Characteristics,” Tribology Transactions, vol. 39, No. 2, pp. 455-461, 1996. 

H. Rachoor and A. Harnoy., “Modeling of Dynamic Friction in Lubricated Line Contacts for Precise Motion Control, ” Tribology Transactions, STLE, vol. 39, 2, pp. 476-482, 1996.   

A. Harnoy, “Model Based Investigation of Friction During the Start-up of Hydrodynamic Journal Bearings,” Transactions of the ASME, J. of Tribology, Vol. 117, pp. 667-672, Oct. 1995.  

A. Harnoy, B. Friedland, R. Semenock, H. Rachoor and A. Aly, “Apparatus for Empirical Determination of Dynamic Friction,” Proceedings of ACC conference, Baltimore, Maryland, June 29-July 1, vol. 1, pp. 545-550, 1994.  

A. Harnoy, B. Friedland and H. Rachoor, “Modeling and Simulation of Elastic and Friction Forces in Lubricated Bearings for Precise Motion Control,” Wear, J. of science and Technology, Oxford, vol. 12, p.p. 155-165, 1994. 

A. Harnoy and B. Friedland, “Dynamic Friction Model of Lubricated Surfaces for Precise Motion Control,” Tribology Transactions, vol. 37, no. 3, pp. 608-614, July 1994.

A. Harnoy, “The Relation Between CDM Instability and Deborah Number in Differential Type Rheological Equations” Rheologica Acta, Vol. 32, pp. 483-489.   

A. Harnoy and H. Rachoor, “Angular-Compliant Hydrodynamic Bearing Performance Under Dynamic Loads,” ASME Transaction, Journal of Tribology, Vol. 115, pp. 342-347, 1993.   

A. Harnoy, “Enhancing Machine Tool Performance By Non-contact Hydrostatic Bearings,” presented at 9th International CAD/CAM, Robotics and Factories of the Future conference, Newark 18-20, Proceedings, Published by Elsevier, 1993.   

A. Harnoy 1997 and H. Zhu, “The role of the Elasticity of the lubricant in Rotor Dynamics,” Tribology Transactions, Vol. 34, pp. 353-360, 1991.  

A. Harnoy, "Investigation of Instability in Rheological Equations of the Differential Type". Proceedings, Third European Rheology Conference, 1990. Published by Elsevier Applied Science. 1990, pp. 208-210.  

A. Harnoy and S.S. Sood, “Viscoelastic Effects in the Performance of Dynamically loaded, Short Journal Bearings,” Transactions of the ASME, Journal of Tribology, vol. 111, pp. 555-556, July 1989. 

A. Harnoy "Normal Stresses and Relaxation Effects in Viscoelastic Boundary Layer Flow Past Submerged Bodies." Journal of Rheology, Vol. 33, 1989, pp. 93-117

A. Harnoy, " Investigation of Automatic Assembly Methods" CAD/CAM, Robotics and Factories of the Future, Vol. 3. Robotics and Plant Automation. Published by Springer-Verlag, Berlin, 1988, pp. 49-53.  

A. Harnoy and S.S. Sood, " Optimization of Angular Position and Location Accuracy in Robots". Robotics and Factories of the Future, Published by Springer-Verlag, Berlin, 1987 pp. 338-345.  

Harnoy, A., "An Investigation into the flow of Elastico-Viscous Fluids Past a Circular Cylinder". Rheologica Acta , Vol. 26, 1987, pp. 493-498.  

Harnoy, A., "Squeeze Film Flow of Elastic Fluids at Steady Motion and Dynamic Loads", ASME Transactions, Journal of Tribology, 1987, Vol. 109, pp. 691-695.  

Harnoy, A. and Radajewski, W., "Optimization of Grain Drying- with Rest Periods", Journal of Agricultural Engineering Research (U.K.), Vol. 27. 1982, pp.291-307. 

Harnoy, A., "The role of the Fluid Relaxation Time in Laminar Elastico-Viscous Boundary Layers". Rheologica Acta, Vol. 18, 1979, pp. 220-216. 

Harnoy A., "An Analysis of Stress Relaxation in Elastico-Viscous Fluid Lubrication of Journal Bearings", ASME Transactions, Journal of Lubrication Technology, Vol. 100, April 1978, pp. 287-295. 

Harnoy, A., "Three Dimensional Analysis of the Elastico-Viscous Lubrication of Journal Bearings", Rheologica Acta, Vol. 16, pp. 51-60, 1977.  

Harnoy, A., "Stress Relaxation Effect in Elastico-Viscous Lubricants in Gears and Rollers", Journal of Fluid Mechanics, Cambridge U.K., Vol. 19, 1976, pp. 501-517.

Harnoy, A. and Phillippoff, W., "Investigation of Elastico-Viscous Lubrication of Sleeve Bearing", ASLE Transactions, Vol. 19, 1976, pp. 301-308. 

Harnoy, A. and Friedman, M.Y., "Decreasing Angular Position Errors in Machine Tools by Adding a Degree of Freedom", Israel Journal of Technology, Vol. 13, 1975, pp. 287-292.

Harnoy, A. and Hanin, M., "Second Order, Elastico-Viscous Lubricants in Dynamically Loaded Bearings", ASLE Transactions, Vol. 17, 1974, pp. 166-171.

Harnoy, A., "The Effects of Stress Relaxation and Cross Stresses in Lubricants with Polymer Additives", CNRS publication, No. 233, 1974, pp.37-44. 

Harnoy, A. and Reiner, M., "Second Order Stresses in Classical Infinitesimal Elasticity", Israel Journal of Technology, Vol. 11, 1973, pp. 325-328.   

Levy, K., Harnoy, A., and Bar-Nefi, S., " Composite Bearing, Rolling Element with Hydrodynamic Journal", Israel Journal of Technology, Vol. 10, 1972, pp. 271-278.

Friedman, M. and Harnoy, A., "Optimization of Angular Positioning Time in Numerically Controlled Machine Tools", Israel Journal of Technology, Vol.10, 243-246. 

Reiner, M., Hanin, M. and Harnoy, A., "An Analysis of Lubrication with Elastico-Viscous Liquid", Israel Journal of Technology, Vol. 7, 1969, pp. 273-279.