Dr. WONG, P.L., PatrickBSc-MechE(CityULondon), PhD(HKU)
Associate Professor
Contact InformationOffice:YEUNG-B6621
Phone:+(852)-3442-8427
Email:meplwong@cityu.edu.hk
Research InterestsTribology
Rolling element bearings
Interfacial slippage
Contact mechanics

Main Research Activities Tribology Actively involved in Tribology research for over thirty years.
Developed an efficient and robust technique for the measurement of a wide lubricating film thickness range from micro to nanometers.
Currently studying on lubrication system with film thickness ranging from micro to nano scales.
Rolling element bearings Life of rolling ball bearings in contaminated conditions through tailored experiment, microscopy and finite-element modeling.
New lubrication mechanism for bearings running under zero entrainment condition.
Invented a new retainerless rolling element bearing type.
Interfacial slippage Successfully developed a novel lubrication means to facilitate effective lubrication of parallel faces – a common feature in micro/nano systems based on the principle of interfacial slippage between the fluid and solid surfaces.
Contact mechanics Invented a new algorithm to solve 3D contact problems, enabling the solutions of any wedge, not only restricted to wedge angle of half-space) or quarter-space.
Developed an efficient and explicit method to obtain the surface deformation of quarter-space under normal load.
Selected Recent PublicationsGuo L., Zhang Z.M., Wang W., Zhao Y. and Wong P.L., “An explicit solution to a three-dimensional wedge problem considering two edges effect”, Friction, DOI:10.1007/s40544-019-0265-7, April 2019.
Zhao Y., Wong P.L. and Mao J.H., “Solving coupled boundary slip and heat transfer EHL problem under large slide–roll ratio conditions”, Tribology International, Vol. 133, pp.73-87, 2019.
Liu C.L., Guo F. and Wong P.L., “Characterisation of starved hydrodynamic lubricating films”, Tribology International, Vol. 131, pp.694-701, 2019.
Wong P.L., Zhao Y. and Mao J., “Facilitating effective hydrodynamic lubrication for zero-entrainment velocity contacts based on boundary slip mechanism”, Tribology International, Vo. 128, 89-95, Jul. 2018.
Guo F., Zang S., Li C., Wong P.L. and Guo L., “Lubrication ?lm generation in slider-on-disc contact under limited lubricant supply”, Tribology International, Vol. 125, pp.200-208, 2018.
Zhao Y., Wong P.L., and Mao J.H., “EHL film formation under zero entrainment velocity condition”, Tribology International, Vol. 124, pp.1-9, Mar. 2018.
Guo L., Wong P.L. and Gachot C., “Facilitating the study of the texturing effect on hydrodynamic lubrication”, Lubricants, 6, 1, Mar. 2018.
Li X.M., Guo F., Wong P.L. and Zhao Y., “Regulation of lubricant supply by wettability gradient in rolling EHL contacts”, Tribology International, Vol. 120, pp.565-574, Apr. 2018.
Bai Q., Guo F., Wong P.L. and Jiang P., “Online Measurement of Lubricating Film Thickness in Slider-on-Disc Contact Based on Dichromatic Optical Interferometry”, Tribol. Lett., 65, 145, 10 pages, Oct., 2017.
Guo L., Zhang Z.M., Wang W. and Wong P.L., “An explicit matrix algorithm for solving three-dimensional elastic wedge under surface loads”, International Journal of Solids and Structures, Vol.128, pp.231-242,2017.
Guo L., Wang W., Zhang Z.M., and Wong P.L., “Study on the free edge effect on finite line contact elastohydrodynamic lubrication”, Tribology International, Vol., 116, pp.482-490, Aug. 2017. DOI:10.1016/j.triboint.2017.08.010
Liu H.C., Guo F., Wong P.L. and Li X., “Investigation of adsorbed protein and passive films on hydrodynamic lubricated steel slider surface”, Tribology International, Vol. 109, pp. 133-139, May 2017.
Wang W., Guo L., Wong P.L. and Zhang Z.M., “Surface normal deformation in elastic quarter-space”, Tribology International, Vol. 114, pp.358-364, Oct. 2017.
Guo L, Wong P.L. and Guo F., “Identifying the optimal interfacial parameter correlated with hydrodynamic lubrication”, Friction, Dec. 2016, 4(4), 347-358.
Guo L., Wong P.L. and Guo F., “Effects of viscosity and sliding speed on boundary slippage in thin film hydrodynamic lubrication”, Tribology International, Vol. 107, pp.85-93, 2017.
Guo L., Wong P.L. and Guo F., “Boundary yield stress and interfacial potential energy barrier in thin film hydrodynamic lubrication”, Tribology Letter, 62(1), pp.1-8, March 2016.
Liu H.C., Guo F., Zhang B.B. and Wong P.L., “Behaviour of hydrodynamic lubrication films under non-steady state speeds”, Tribology International, Vol. 93, Part A, pp.347-354, Jan 2016.
Li X., Guo F. and Wong P.L., “Effect of bovine serum albumin aqueous solution on steel slider surface under hydrodynamic lubrication”, presented at the 41st Leeds/Lyon Symposium on Tribology, Leeds, England, September 2014, and also Tribology International, Vol. 93, Part B, pp. 495-501, Jan. 2016.
Guo L., Wong P.L. and Guo F., “Correlation of contact angle hysteresis and hydrodynamic lubrication”, Tribology Letters, Vol. 58, 45, pp. 1-9, June 2015.
Liu H.C., Guo F., Guo L. and Wong P.L., “A dichromatic interference intensity modulation approach to measurement of lubricating film thickness”, Tribology Letters, Vol. 58:15, pp. 1-11, April 2015.
Fu Z., Wong P.L. and Guo F., “Localized boundary effect on elastohydrodynamic lubricated film shape”, Tribology Letters, Vol. 56, pp.471-479, Dec. 2014.
Guo L., Wong P.L., Guo F. and Liu H.C., “Determination of thin hydrodynamic lubricating film thickness using dichromatic interferometry”, Applied Optics, 53, 26, Sep. 2014.
Guo F., Yang S.Y., Ma C. and Wong P.L., “Experimental study on lubrication film thickness under different interface wettabilities”, Tribology Letters, Vol. 54, 1, pp.81-88, Apr. 2014.
Fu Z., Wong P.L. and Guo. F., “Effect of interfacial properties on EHL under pure sliding conditions”, Tribology Letters, Vol. 49, 1, pp.31-38, Jan. 2013.
Wong P.L., Li X.M. and Guo F., “Evidence of lubricant slip on steel surface in EHL contact”, Tribology International, Vol. 61, pp.116-119, May 2013.
Zhang Z.M., Wang W. and Wong P.L., “An explicit solution for the elastic quarter-space problem in matrix formulation”, International Journal of Solids and Structures, Vol. 50, 6, pp.976-980, Mar. 2013.
Li X.M, Guo F. and Wong P.L., “Shear rate and pressure effects on boundary slippage in highly stressed contacts”, presented at the 38th Leeds/Lyon Symposium on Tribology, Lyon, France, September 2011, and also Tribology International, Vol. 59, pp.147-153, Mar. 2013.
Li X., Guo F., Yang S. and Wong P.L., “Measurement of load-carrying capacity of thin lubricating films”, TRANS. ASME J. OF TRIBO., 134, 4, art. No.044501, 2012.
Lau H.Y., Liu K.P., Wong P.L. and Wang W., “A new design of smart journal bearing based on GMM actuators”, Industrial Lubrication and Tribology, Vol.64, Iss:3, pp.147-151, 2012.
Fu Z., Guo F. and Wong P.L., “Friction-speed characteristics of EHL contacts with anomalous film shapes”, Proceedings of the I MECH E Part J Journal of Engineering Tribology, 226, 2, 81-86, February 2012.
Chow T.C.S., Wong P.L. and Liu K.P., “Shape effect of magnetic source on stabilizing range of vertical diamagnetic levitation”, IEEE TRANS. MAGNETICS, 48, 1, art. no. 6034526, pp.26-30, 2012.
Li X.M, Guo F. and Wong P.L., “Study of boundary slippage using movement of a post-impact EHL dimple under conditions of pure sliding and zero entrainment velocity”, Tribology International, Vol.44, 2, pp.159-165, Nov. 2011.
Li X.M, Guo F. and Wong P.L., “Movement of entrapped oil under pure rolling conditions”, presented at International Tribology Congress ASIATRIB 2010, Perth, Australia, 5-9 December 2010, and also Tribology Letters, Vol.43, 2, pp.129-137, August 2011.
Guo F., Li X.M. and Wong P.L., “A novel approach to measure slip-length of thin lubricant films under high pressure”, presented at the 37th Leeds/Lyon Symposium on Tribology, Leeds, England, September 2010, and also Tribology International, Vol.46, No. 1, pp.22-29, Feb. 2012.
Chan Y.T., Wong P.L., Liu K.P. and Bullough W.A., “Repulsive normal force by an excited magneto-rheological fluid bounded by parallel plates in stationary or rotating shear mode”, J. INTEL. MAT. SYS., Vol.22, 6, pp.551-560, April 2011.
Liu X., Wong P.L., Wang W. and Bullough W.A., “Feasibility study on the storage of magneto-rheological fluid using metal foams”, J. INTEL. MAT. SYS., Vol.21, 12, pp.1193-1200, August 2010.
Wong P.L., He F. and Zhou X., “Interpretation of the hardness of worn DLC particles using micro-Raman spectroscopy”, presented at the 36th Leeds/Lyon Symposium on Tribology, Lyon, France, September 2009, and also Tribology International, Vol.43, No. 10, pp.1806-1810, October 2010.
Guo F., and Wong P.L., “Full and partial boundary slippage effect on squeeze film bearings”, Tribology International, Vol.43, No. 5-6, pp.997-1004, May 2010.
He F., Wong P.L. and Zhou X., “Wear properties of DLC-coated steel rollers running with highly contaminated lubrication”, Tribology International, Vol.43, No. 5-6, pp.990-996, May 2010.
Guo F., Wong P.L., Fu Z., and Ma C., “Interferometry measurement of lubricating films in slider-on-disc contacts”, Tribology Letters, Vol.39, No.1, pp.71-79, July 2010.
Guo F., Wong P.L., Geng M. and Kaneta M., “Occurrence of wall slip in elastohydrodynamic lubrication”, Tribology Letters, Vol.34, pp.103-111, February 2009.
Fu Z., Guo F. and Wong P.L., “Theoretical study on the interferometry of thin EHL film measurement”, Tribology Letters, Vol.31, No. 1, pp.57-65, July 2008.
Guo. F., Fu Z., Wong P.L. and Yang P., “Experimental study on the lubrication regime variation in point contacts”, Tribology International, Vol.41, No. 6, pp.451-460, June. 2008.
Wang W., Wong P.L., He F. and Wan G.T.Y., “Experimental study of the smoothing effect of a ceramic rolling element on a bearing raceway in contaminated lubrication”, Tribology Letters, 28, 1, pp.89-97, Oct. 2007.
Fu Z., Guo F. and Wong P.L., “Non-classical elastohydrodynamic lubricating film shape under large slide-roll ratios”, Tribology Letters, 27, 2, pp.211-219, Aug. 2007.
Guo F. and Wong P.L., “Theoretical prediction of hydrodynamic effect by tailored boundary slippage”, Proceedings of the I MECH E Part J Journal of Engineering Tribology, Vol.220, pp.43-48, Mar. 2006.
Guo F. and Wong P.L., “An anomalous elastohydrodynamic lubrication film – inlet dimple”, Trans. ASME J. of Tribo., Vol. 127, No. 2, pp.425-434, Apr. 2005.
Wang W., Wong P.L. and Guo F., “Application of partial elastohydrodynamic lubrication analysis in dynamic wear study for running-in”, Wear, Vol.257, 7-8, pp.823-832, Oct. 2004.
Leung W.C., Bullough W.A., Wong P.L. and Feng C., “The effect of particle concentration in a magneto rheological suspension on the performance of a boundary lubricated contact”, Proceedings of the I MECH E Part J Journal of Engineering Tribology, Vol.218, pp.251-263, Sep. 2004.
Guo F. and Wong P.L., “A wide range measuring system for thin lubricating film: from nano to micro thickness”, Tribology Letters, Vol. 17, No. 3, pp.521-531, Oct. 2004.
Guo F. and Wong P.L., “Experimental observation of a dimple-wedge elastohydrodynamic lubricating film”, Tribology International, Vol.37, No. 2, pp.119-127, Feb. 2004.
Wong P.L., Guo F., and Feng C., “The measurement of the refractive index of a liquid lubricant at high pressure within an EHL impact dimple using a single optical interferogram”, Tribology International, Vol.36, No. 7, pp.497-504, Jul. 2003.
Wang W., and Wong P.L., “The dynamic measurement of surface topography by a light-section technique”, Tribotest. 9-4, pp.305-316, June 2003.
Jiang H., Wong P.L., Meng Y., and Wen S., “An indirect electric field effect on the friction of boundary lubricated contact”, Lubrication Science, 15-3, pp.275-292, May 2003.
Wong P.L., Huang P., and Meng Y., “The effect of the electric double layer on very thin water lubricating film”, Tribology Letters, Vol.14, No.3, pp.197-203, April 2003.
Bullough W.A., Wong P.L., Feng C. and Leung W.C., “Fundamental boundary Tribology: ESF”, J. Intel. Mat. Sys., Vol.14, No.2, pp.71-78, Feb. 2003.
Guo F., and Wong P.L., “A multi-beam intensity-based for lubricant film measurements in non-conformal contacts”, Proceedings of the I MECH E Part J Journal of Engineering Tribology, Vol.216, 5, pp.281-291, Oct. 2002.
Guo F., Wong P.L., Yang P., and Yagi K., “Film formation in EHL point contacts under ZEV conditions”, STLE Tribology Transaction, Vol.45, No.4, pp.521-530, Oct. 2002.
Meng Y, Jiang H., and Wong P.L., “An experimental study on voltage-controlled friction of alumina/brass couples in zinc stearate/water suspension”, STLE Tribology Transaction, Vol.44, No.4, pp.567-574, Oct. 2001.
Guo F., Yang P., and Wong P.L., “On the thermal elastohydrodynamic lubrication in opposite sliding circular contacts”, Tribology International, Vol.34, No. 7, pp.443-452, Jul. 2001.
Jiang H., Wong P.L., and Meng Y., “Influence of ‘off-contact’ electric potential on frictional behaviours of agate/brass (SiO2/Cu) rubbing couple”, Proceedings of the I MECH E Part J Journal of Engineering Tribology, Vol.215, 2, pp. 201-206, Apr. 2001.
Wong P.L., Bullough W.A., Feng C., and Lingard S., “Tribological Performance of a Magneto Rheological Suspension”, Wear, Vol.247, 1, pp.33-40, Jan. 2001.
Wang W., and Wong P.L., “Wear Volume Determination During Running-in for PEHL Contacts”, Tribology International, Vol. 33, No. 7, pp.501-506, Jul. 2000.
Wang W., Wong P.L., and Zhang Z., “Experimental Study of the Real Time Change in Surface Roughness During Running-in for PEHL Contacts”, Wear, Vol.244, 1-2, pp.140-146, Aug. 2000.
Last modified on 6 August, 2019