Yuichi MURAI

J-GLOBAL         Last updated: Sep 5, 2019 at 14:34
 
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Name
Yuichi MURAI
URL
http://ring-me.eng.hokudai.ac.jp/murai/index.html
Affiliation
Hokkaido University
Section
Faculty of Engineering Division of Energy and Environmental Systems
Job title
Professor
Degree
PhD.(The University of Tokyo)

Profile

Laboratory for Flow Control (LFC) deals with experimental research on various energy and environmental problems issued in the field of mechanical engineering. We develop ship drag reduction technology, food engineering device, 3D-driven wind turbine, geo-thermofluid physics, and fuel flowmetering management. Particle image velocimetry (PIV) and ultrasound velocity profiling (UVP) support new discoverty of fluid mechanics and assist new design of fluid machinaries.

Research Areas

 
 

Academic & Professional Experience

 
Apr 1993
 - 
Mar 1995
JSPS Research Fellow, Graduated School of Engineering, The University of Tokyo
 
Apr 1995
 - 
May 2000
Research Associate, Faculty of Engineering, Fukui University
 
Jun 2000
 - 
Feb 2001
Associate Professor, Faculty of Engineering, Fukui University
 
Mar 2001
 - 
Mar 2003
Visiting Researcher, Imperial College London
 
Apr 2003
 - 
Mar 2005
Associate Professor, Graduate School of Engneering, Hokkaido University
 
2010
   
 
- Professor
 
Apr 2005
 - 
Mar 2010
Associate Professor, Graduate School of Engineerig, HokkaidoUniversity
 
Apr 2010
 - 
Today
Professor, Faculty of Engineering, Hokkaido University
 

Education

 
 
 - 
1989
Department of Mechanical Engineering, Faculty of Engineering, Ishikawa National College of Technology
 
 
 - 
Mar 1989
Department of Mechanical Engineering, Ishikawa National College of Technology
 
 
 - 
1991
Department of Mechanical System Engineering, Faculty of Engineering, Kanazawa University
 
 
 - 
Mar 1991
Faculty of Engineering, Kanazawa University
 
 
 - 
1995
Division of Mechanical Engineering, Graduate School, Division of Engineering, The University of Tokyo
 

Awards & Honors

 
Jul 2018
Ultrasonic food rheometry, Technology Award, Visualization Soc Japan
 
Apr 2017
Technology Award, JSME
 
Feb 2017
Outstanding Reviewer's Award, IOP
 
Mar 2016
Wind farm birdstrike prevention, Branch Award, JSME
 
Jun 2015
Technical Award, Visualization Soc Japan
 
Jul 2014
Technical Award, Japan Society of Multiphase Flow
Winner: Yuichi MURAI, et al
 
Jul 2014
Techncal Paper Award, Visualization Society of Japan
Winner: Takahisa Shiratori, et al
 
Jul 2012
Technical Paper Award, JSMF
 
Oct 2011
Fluid Eng Div. Frontier Award, JSME
 
2010
JGA Technical Award
 
2008
VSJ Technical Award
 
2008
JSME FED Dreamy Flow Contest Best Prize
 
2008
JSME FED Dreamy Flow Contest Excellent Prize
 
Apr 2007
Minister Award, MEXT
 
2007
JSME FED Dreamy Flow Contest Ichiju Prize
 

Published Papers

 
Color-coded visualization of microbubble clouds interacting with eddies in a spatially developing turbulent boundary layer
H.J.Park, D.Saito, Y.Tasaka, Y.Murai
Experimental Thermal and Fluid Science   (accepted)    Sep 2019   [Refereed]
Bubble clustering in a horizontal turbulent channel flow investigated via bubble-tracking velocimetry
Y.Oishi, Y.Tohge, Y.Murai, Y.Tasaka
International Journal of Multiphase Flow   111    Sep 2019   [Refereed]
Cloud clustering of microbubbles ascending along a vertical wall proximity
T.Watamura, A.Kitagawa, Y.Murai
Chemical Engineering Science   208 115132   Aug 2019   [Refereed]
Quantitative visualization of vortex ring structure during wall-impingement subject to background rotation
Y.Oishi, Y.Murai, Y.Tasaka
Journal of Visualization   23    Jul 2019   [Refereed]
Thermal diffusion interface inside a horizontal pipe flow compared between laminar and turbulent flow regimes
K.Nakamura, H.J.Park, Y.Murai, T.Takeuchi
Journal of Visualization   22 809-818   Jun 2019   [Refereed]
Efficacy assessments in ultrasonic spinning rheometry: linear viscoelastic analysis on non-Newtonian fluids
T.Yoshida, Y.Tasaka, Y.Murai
Journal of Rheology   63 503   Apr 2019   [Refereed]
Horizontal diffusive motion of columnar vortices in rotating Rayleigh-Bénard convection
D.Noto, Y.Tasaka, Y.Murai, T.Yanagisawa
Journal of Fluid Mechanics   871 401-423   Apr 2019   [Refereed]
Pressure field estimation from ultrasound Doppler velocity profiler for vortex-shedding flows
N.Tiwari, Y.Murai, T.Tasaka
Flow Measurement and Instrumentation, Vol. 67, pp. 23-32 (2019)      Mar 2019   [Refereed]
Transition from convection rolls to large-scale cellular structures in turbulent Rayleigh-Benard convection in a liquid metal layer
M.Akashi, T.Yanagisawa, Y.Tasaka, T.Vogt, Y.Murai, S.Eckert
Physical Review Fluids, Vol.4, No. 3, 033501 (2019)      Feb 2019   [Refereed]
Behavior of bubbles moving along horizontal flat plates with different surface wettability
A.Kitagawa, P.Denissenko, Y.Murai
Experimental Thermal and Fluid Science, Vol.104, pp.141-152 (2019)      Feb 2019   [Refereed]
Bubbly drag reduction investigated by time-resolved ultrasonic pulse echography for liquid films creeping inside a turbulent boundary layer
H.J.Park, Y.Tasaka, Y.Murai
   Jan 2019   [Refereed]
Oil-gas-water three-phase flow characterization and velocity measurement based on time-frequency decomposition
X.Shi, C.Tan, F.Dong, Y.Murai
International Journal of Multiphase Flow, Vol. 111, pp.219-231      Jan 2019   [Refereed]
Modal switching of bubbly Taylor–Couette flow investigated by particle tracking velocimetry
Y.Murai, Y.Tasaka, Y.Oishi and Y.Takeda
Experiments in Fluids, Vol. 59: 164      Aug 2018   [Refereed]
Bubbly drag reduction accompanied by void wave generation inside turbulent boundary layers
H.J.Park, Y.Tasaka, Y.Murai
Experiments in Fluids, Vol. 59: 164      Aug 2018   [Refereed]
Vortex tracking on visualized temperature fields in a rotating Rayleigh-Bénard convection
D.Noto, Y.Tasaka, T.Yanagisawa, H.J.Park, Y.Murai
Journal of Visualization, Vol.21, pp.987-998      Jul 2018   [Refereed]
Rheological properties of montmorillonite dispersions in dilute NaCL concentration investigated by ultrasonic spinning rheometry
T.Yoshida, Y.Tasaka, S.Tanaka, H.J.Park, Y.Murai
Applied Cray Science, Vol.161, pp.513-523      Apr 2018   [Refereed]
Dispersed oil-water two-phase flow measurement based on pulse-wave ultrasonic Doppler coupled with electrical sensors
C.Tan, W.Liu, F.Dong, Y.Murai
IEEE Transactions on Instrumentation & Measurement, Vol. 67, No. 9, pp.2129-2132      Mar 2018   [Refereed]
Inner structure visualization of fresh fruits utilizing ultrasonic velocity profiler
T.Yoshida, Y.Tasaka, H.J.Park, Y.Murai, H.Teramura, S.Koseki
Journal of Visualization, Vol. 21, pp.253-265      Feb 2018   [Refereed]
Linear viscoelastic analysis using frequency-domain algorithm on oscillating circular shear flows for bubble suspensions
Y.Tasaka, T.Yoshida, R.Rapberger, Y.Murai
Rheologica Acta, Vol. 57, pp.229-240      Jan 2018   [Refereed]
Ultrasound flow-monitoring and flow-metering of air–oil–water three-layer pipe flows
J.Hitomi, Y.Murai, H.J.Park, Y.Tasaka
IEEE Access, Vol.5      Jul 2017   [Refereed]
A.Kitagawa, P.Denissenko, Y.Murai
International Journal of Heat and Mass Transfer, Vol. 113      Apr 2017   [Refereed]
B. van Ruymbeke, Y.Murai, Y.Tasaka, Y.Oishi, C.Gabillet, C.Colin, N.Latrache
Journal of Visualization, Vol. 20      Apr 2017   [Refereed]
T.Yoshida, Y.Tasaka, Y.Murai
Journal of Rheology, Vol. 61      Apr 2017   [Refereed]
Influence of microbubbles on turbulent puffs in pipe flows
混相流, Vol. 31      Apr 2017   [Refereed]
A.Kitagawa, Y.Murai, P.Denissenko
Experimental Thermal and Fluid Science, Vol. 80      Apr 2017   [Refereed]
Y.Murai
Measurement Science and Technology, Vol. 27      Dec 2016   [Invited]
H.J.Park, Y.Oishi, Y.Tasaka, Y.Murai
Experiments in Fluids, Vol. 57      Oct 2016   [Refereed]
T.Takeuchi, J.Ohkubo, N.Yonezawa, Y.Oishi, I.Kumagai, Y.Tasaka, Y.Murai
International Journal of Multiphase Flow, Vol.87      Oct 2016   [Refereed]
J.Ohkubo, Y.Tasaka, H-J.Park, Y.Murai
Journal of Visualization, Vo.19      Oct 2016   [Refereed]
T.Nakashima, T.Shiratori, Y.Murai, Y.Tasaka, Y.Takeda, E.J.Windhab
Flow Measurement and Instrumentation, Vol.48      Apr 2016   [Refereed]
Y.Murai, T.Shiratori, I.Kumagai, P.A. Ruehs, P.Fischer
Flow Measurement and Instrumentation, Vol. 41      Apr 2016   [Refereed]
H.J. Park, Y.Tasaka, Y.Murai
Measurement Science and Technology, Vol. 26      Oct 2015   [Refereed]
T.Shiratori, Y.Tasaka, Y.Murai
Experimental Thermal and Fluid Science, Vol. 71      Apr 2016   [Refereed]
T.Shiratori, Y.Tasaka, Y.Oishi, Y.Murai
Measurement Science and Technology, Vol. 26      Oct 2015   [Refereed]
H.J.Park, Y.Tasaka, Y.Oishi, Y.Murai
International Journal of Multiphase Flow   75    May 2015   [Refereed]
Y.Tasaka, T.Kimura, Y.Murai
Experiments in Fluids   56    Feb 2015   [Refereed]
Y.Murai, T.Shiratori, I.Kumagai, P.A. Ruehs, P.Fischer
Flow Measurement and Instrumentation   41    Jan 2015   [Refereed]
Y.Murai
Experiments in Fluids   (accepted)    Jul 2014   [Refereed][Invited]
A.Kitagawa, Y.Murai
Chemical Engineering Science   116    Jun 2014   [Refereed]
H.J. Park, Y.Tasaka, Y.Oishi, Y.Murai
Chemical Engineering Science   116    May 2014   [Refereed]
Y. Oishi, Y.Murai
Experimental Thermal and Fluid Science   55    Apr 2014   [Refereed]
A.Kitagawa, T. Mimura, M. Ishikawa, Y.Murai
Journal of Visualization   16    Oct 2013   [Refereed]
T.Shiratori, Y.Tasaka, Y.Murai, Y.Takeda
Journal of Visualization   16    Oct 2013   [Refereed]
Y.Murai, J.H.Vlaskamp, Y.Nambu, T.Yoshimoto, P.Denissenko, and P.J. Thomas
Experimental Thermal and Fluid Science   51    Oct 2013   [Refereed]
A.Kitagawa, Y.Murai
Chemical Engineering Science   99    Jul 2013   [Refereed]
M.Yamada, Y.Murai, I.Kumagai
Journal of Visualization   16    Jul 2013   [Refereed]
T.Watamura, Y.Tasaka, Y.Murai
Physics of Fluids   25    Jun 2013   [Refereed]
T.Watamura, Y.Tasaka, Y.Murai
Experimental Thermal and Fluid Science   47 68-80   Mar 2013   [Refereed]
T.Watamura, Y.Tasaka, Y.Murai
Theoretical and Applied Mechanics Japan   61    Feb 2013   [Refereed]
Flow visualization around a hydrofoil close to a free surface
I.Kumagai, T.Kushida, K.Oyabu, Y.Tasaka, Y.Murai
Visualization of Mechanical Processes   3(3-120) 1-7   Jun 2012   [Refereed]
Journal of Visualization   13(4) 355-363   2010   [Refereed]
Renewable Energy   36(2) 536-545   2010   [Refereed]
Ultrasonic detection of moving interfaces in gas-liquid two-phase flow
Flow Measurement and Instrumentation   36 536   2010   [Refereed]
Visualization of transient interfacial waves induced by spin-up of two immiscible fluid layers
Journal of Visualization   10 1007   2009   [Refereed]
Flow Measurement and Instrumentation   19(2) 93-105   2008   [Refereed]
Fluid Dynamics Research   40(7-8) 565-575   2008   [Refereed]
Frictional drag reduction in bubbly Couette-Taylor flow
Physics of Fluids   10(3) 1-8   2008   [Refereed]
Measurement Science and Technology   18(8) 2491-2503   2007   [Refereed]
Flow Measurement and Instrumentation   18(5-6) 223-229   2007   [Refereed]
International Journal of Multiphase Flow   33(2) 147-163   2007
Flow Measurement and Instrumentation   17(5) 267-275   2006   [Refereed]
Nuclear Engineering and Design   236(1) 94-106   2006   [Refereed]
Yuichi MURAI, Hideki FUJII, Yuji TASAKA, Yasushi TAKEDA
Journal of Fluid Science and Technology   1(1) 12-23   2006   [Refereed]
Multiphase Science and Technology   18(2) 175-197   2006   [Refereed]
Measurement of Bubble-Bubble Interaction Depended on Reynolds Number Using Stereoscopic Bubble-Tracking Technique
Journal of Hydrodynamics, Ser.B   17(2) 243-251   Sep 2005   [Refereed]
Flow Measurement and Instrumentation   16(1) 35-46   2005   [Refereed]
IOP Journal of Physics: Conference Series: Vol.14, 14th International Couette-Taylor Workshop -Sapporo 2005 (2005)
Institute of Physics UK      2005
Simultaneous PIV/PTV Measurement of Bubble and Particle Phases in Gas-Liquid Two-Phase Flow Based on Image Separation and Reconstruction
J.W.Qu, Y.Murai, F.Yamamoto
Journal of Hydrodynamics, Ser.B   16 756-766   Apr 2004   [Refereed]
International Journal of Multiphase Flow   30(10) 1213-1234   2004   [Refereed]
Y.Murai, T.Ido, F.Yamamoto
JSME International Journal, Series B   45 142-149   2002   [Refereed]
Ido,T., Murai,Y., Yamamoto, F
Experiments in Fluids   32(3) 326-336   2002   [Refereed]
Kitagawa,A., Murai, Y., Yamamoto, F
International Journal of Multiphase Flow   27(12) 2129-2153   2001   [Refereed]
Shen,L., Song, X., Murai, Y., Iguchi, M., Yamamoto, F.
Flow Measurement and Instrumentation   12(3) 191-199   2001   [Refereed]
Murai,Y., Matsumoto,Y., and Yamamoto,F.
Experiments in Fluids   30(1) 11-21   2001   [Refereed]
A Novel Algorithm for Particle Tracking Velocimetry using the Velocity Gradient Tensor
M.Ishikawa, Y.Murai, A.Wada, M.Iguchi, K.Okamoto, F.Yamamoto
Experiments in Fluids, Vol.29, No.6, 519-531(2000)      Sep 2000   [Refereed]
Numerical Validation of Velocity Gradient Tensor Particle Tracking Velocimetry for Highly Deformed Flow Fields
M.Ishikawa, Y.Murai, F.Yamamoto
Measurement Science and Technology, Vol.11, No.6, pp.677 - 684.(2000)      Jun 2000   [Refereed]
Inverse Energy Cascade Structure of Turbulence in a Bubbly Flow(Numerical Analysis using Eulerian-Lagrangian Model Equations)
Y.Murai, A.Kitagawa, X.Song, J.Ohta, F.Yamamoto
JSME International Journal, Series B, Vol.43, No.2,pp.197-205 (2000)      May 2000   [Refereed]
Inverse Energy Cascade Structure of Turbulence in a Bubbly Flow(PIV Measurement and Results)
Y.Murai, X.Song, T.Takagi, M.Ishikawa, F.Yamamoto, J.Ohta
JSME International Journal, Series B, Vol.43, No.2,pp.188-196 (2000)      May 2000   [Refereed]
Numerical Analysis of Turbulence Structures Induced By Bubble Buoyancy
Y.Murai, Y.Matsumoto, X.Song, F.Yamamoto
JSME International Journal, Series B, Vol.43, No.2,pp.180-187 (2000)      May 2000   [Refereed]
Qualitative and Quantitative Flow Visualization of Bubble Motions in a Plane Bubble Plume
Y.Murai, Y.Matsumoto, F.Yamamoto
Journal of Visualization, Vol.3, No.1, 27-35 (2000)      Apr 2000   [Refereed]
Murai,Y. and Matsumoto, Y.
Journal of Fluids Engineering   122(4) 754-760   Dec 2000   [Refereed]
Miyazaki,K., Chen,G., Yamamoto,F., Ohta,J., Murai,Y., and Iguchi,M.
Experimental Thermal and Fluid Science   19(4) 194-203   1999   [Refereed]
Eulerian Analysis of Bubbly Two-Phase Flows using CIP Scheme
Murai,Y. and Matsumoto,Y
Computational Fluid Dynamics Journal   8 26-33   1999   [Refereed]
Song,X., Yamamoto,F., Igucgi,M., Kato,H., Murai,Y., Ishii,K., and Sasaki,Y.
ISIJ International Journal   39 471-476   1999   [Refereed]
Song.X., Yamamoto,F., Iguchi,M., Murai,Y
Experiments in Fluids   26(4) 371-380   1999   [Refereed]
Murai, Y. and Matsumoto, Y.
JSME International Journal, Series B   41(3) 568-574   1998   [Refereed]

Books etc

 
Special issue, Nuclear Engineering and Design
Y.Murai, G.Tryggvason (Part:Joint Work)
Aug 2018   
PIV Handbook 2018
Yuichi MURAI (Part:Joint Work)
Jun 2018   
Special Issue for the 9th International Symposium on Measurement Techniques for Multiphase Flows (ISMTMF2015)
Y.Murai (Part:Editor)
Oct 2016   
Ultrasonic Doppler Velocity Profiler for Fluid Flow
Y.Murai (Part:Joint Work)
Sep 2012   
PIV Handbook
Yuichi MURAI (Part:Contributor)
Apr 2002   

Conference Activities & Talks

 
Velocity profiling rheometry for dispersed multiphase fluids [Invited]
Y.Murai
10th International Symposium on Measurement Techniques for Multiphase Flow - Hong Kong   4 Dec 2017   
Two-phase flow research activities in Japan, U.S., and E.U. [Invited]
Y.Murai, G.Tryggvason, Y.Takeda
11th Japan-U.S. Seminar on Two-Phase Flow Dynamics   23 Jun 2017   
Laboratory experiments and sea-trials on ship drag reduction by bubble injection [Invited]
Y.Murai
9th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics (ExHFT-9)   14 Jun 2017   
Advance of particle tracking velocimetry toward ultimate use in multidisciplinary fields [Invited]
Y.Murai
Special Lecture at Swiss Federal Institute of Technology (ETHZ)   27 Mar 2017   
Bird shadow imaging coupled with wire-frame model analysis for automatic bird species identification [Invited]
Y.Murai, Y.Takeda, H.Kumeno
2nd Meeting of Workgroup of Birdstrike Science and Engineering   31 Oct 2016   
Multi-polar vortex dynamics of dispersion-induced flow control [Invited]
Y.Murai
China Sympoisum on Multiphase Flow Measurement   23 Sep 2016   
Frictional drag reduction by small bubbles versus large bubbles [Invited]
Y.Murai, Y.Tasaka, H.Park
Workshop on Transition Control in Dispersed Flows   13 Jan 2016   
Measurement-based discovery on new function of microbubbles in fluid flow [Invited]
Y.Murai
Internatioal Forum on New Horizons in Multiphase Flow Measurement   10 Dec 2015   
Microbubble-liquid interaction observed in channel flows from laminar, transition, and turbulent regimes [Invited]
Y.Murai, Y.Tasaka, Y.Oishi (keynote)
ASME International Conference on Nano, Micro, and Minichannels   2013   
Fundamentals in frictional drag reduction by bubble injection [Invited]
Y.Murai (keynote)
International Conference on Multiphase Flow 2013   2013   
Paradigm shift in modern flow measurement and gas flow metering [Invited]
Y.Takeda and Y.Murai
International Gas Research Conference - Korea   2012   
Broad destruction of density stratification using a single bubble plume [Invited]
Y.Murai, H.Kayukawa, Y.Tasaka, I.Kumagai, H.Kitaura (keynote)
Japan-US Seminar on Two-Phase Flow Dynamics - Tokyo   2012   
Backlight imaging tomography applied to slug flows in straight and helical tubes [Invited]
Y.Murai, Y.Takeda, F.Yamamoto
5th Int. Symposium on Measurement Techniques for Multiphase Flows   2006   
Turbulent Shear Stress Profiles in a Horizontal Bubbly Channel Flow
Y.Murai, Y.Oishi, T.Sasaki, Y.Kodama, F.Yamamoto (Invited)
6th International Symposium on Smart Control of Turbulence   2005   
Experimental Study on Bubble Behavior Contributing to Frictional Drag Reduction [Invited]
Y.Murai, H.Oiwa, Y.Ooishi, F.Yamamoto
U.S.- Japan Workshop on Microbubble Friction Drag Reduction   2003   
Application of Particle Tracking Velocimetry to Multiphase Flows - New Finding with It
Y.Murai, F.Yamamoto(keynote)
Int. Symp. Optical Methods and Image Processing in Fluid Flow Measurement,ASME/FED & JSME Joint Fluids Conferenc   2003   

Research Grants & Projects

 
JSPS: GAR - Kiban (A)
Project Year: Apr 2012 - Mar 2017    Investigator(s): Yuichi MURAI
JSPS: GAR - Challenge
Project Year: Apr 2011 - Mar 2013    Investigator(s): Yuichi MURAI
NEDO: ITRDP
Project Year: Jun 2008 - May 2012    Investigator(s): Yuichi MURAI
JSPS: GAR - Kiban (B)
Project Year: Apr 2009 - Mar 2011    Investigator(s): Yuichi MURAI
NEDO: ITRDP
Project Year: Jul 2005 - Jun 2008    Investigator(s): Yuichi MURAI
JSPS: GAR - Wakate (B)
Project Year: Apr 2005 - Mar 2008    Investigator(s): Yuichi MURAI
MEXT and JNC: ABER
Project Year: Sep 2003 - Mar 2006    Investigator(s): Yuichi MURAI
JSPS: GAR - Wakate (A)
Project Year: Apr 2003 - Mar 2006    Investigator(s): Yuichi MURAI
JSPS: FRP
Project Year: Mar 2001 - Mar 2002    Investigator(s): Yuichi MURAI
MEXT: Promotion (A)
Project Year: Apr 1999 - Mar 2001    Investigator(s): Yuichi MURAI
JSPS: DC1
Project Year: Apr 1995 - Mar 1997    Investigator(s): Yuichi MURAI
Multiphase Science and Technology
Project Year: 1988   
Development of PIV system
Project Year: 1992   
Innvation of wind power generation technology
Project Year: 1998   
Study on Turbulent Frictional Drag Reduction
Project Year: 1998   
Application of Ultrasonic Doppler Velocimetry
Project Year: 2003   
Large Flow Rate Type Bubble Generator
Project Year: 2008 - 2012

Patents

 
2000-101068
特許 米国:No. US7500837B2 : Small size gear pump
Yuichi MURAI
CP2929823 : Object detection apparatus, objection detection method, and object detection system
Canadian Patent No. 2929823
TWI586992 : Object detection apparatus, objection detection method, and object detection system
Taiwanese Patent No. I586992
TWI604415 : Object detection apparatus, objection detection method, and object detection system
Taiwanese Patent No. I604415
US9721154 : Object detection apparatus, objection detection method, and object detection system
United States Patent No. 9721154
KR10-1900176 : Object detection apparatus, objection detection method, and object detection system
Korean Patent No. 10-1900176
US678941B2 : Friction reduction ship and method for reducing frictional resistance
US Patent US678941B2