A NALYSIS OF THE L UBRICATION S YSTEM IN A H IGH P RESSURE P ISTON W - PowerPoint PPT Presentation

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP A NALYSIS OF THE L UBRICATION S YSTEM IN A H IGH P RESSURE P ISTON W ATER P UMP D. Bottazzi 2 , D. Galloni 1 , M. Milani 2 , L. Montorsi 2 1 - Comet S.p.A. Reggio Emilia, Italy 2 - HY DRAULIC SY STEMS DE SIGN R ESEARCH G ROUP Dept. of Sciences and Methods for Engineering University of Modena and Reggio Emilia, Italy STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP Comet Product Divisions - Task: avoid overheating for long time operation - Numerical Analysis and Optimization of the Lubrication System STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Test rig thermal analysis - CLW (aluminium crank case) 66 l/min (1000 rpm) @ 140 bar Thermocouple measurements 1 – Oil 2 – Water 3 – Air (ambient) 4 – Needle-bearing on the joint side 5 – Needle-bearing on the other side 6 – Crank case, front position 7 – Crank case, close to the valves STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Test rig thermal analysis - CLW (aluminium crank case) 66 l/min (1000 rpm) @ 140 bar Optris PI 160 a) b) • spectral range: 7.5 - 13 µm • temperature range: -20 ° C - 900 ° C • optical resolution: 160 x 120 pixel • picture repetition frequency: 120 Hz c) d) STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Mesh construction, from 3D to 2D - Only one piston is simulated 2D - 300000 cells 1 mm 0.5 mm 3D – millions of cells STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Moving mesh construction - - Overset mesh (rod motion) - - Morphing (piston motion) - • Point B position – Rod big end position • Point A position – Rod small end position           x r sin t     B c 2 sin               2   z r ( 1 1 / ) cos t ( 1 / ) 1 t       A c z r cos t B c • Generic point J         v v BJ tot trans B J B            x r cos t B c             z r sin t B c        cos t             B 2 sin      2  1 t  STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – VOF – air&oil- - Oil properties, T & p dependence -             4 c C C T / T V / V / p 2 3 oil oil _ ref oil oil _ ref oil oil            7 . 6        3 k C C V / V 1 0 . 101 T / T V / V oil 0 1 oil oil _ ref oil oil _ ref oil oil _ ref W. Habchi, P. Vergne, S. Bair, O. Andersson, D. Eyheramendy, G.E. Morales-Espejel - Influence of pressure and temperature dependence of thermal properties of a lubricant on the behaviour of circular TEHD contacts , Tribol. Int. 43 (2010) 1842 – 1850. STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP - Friction evaluation -       1          P P 2 P 3 P P P P ftot hyd hm fnb frbe frse fjb fring 35% 65%     P Q p p        hyd max suc   tot vol hm P M mech max                2 Q / 3 2 r d / 4 vol c p - Needle bearings -     M 0 . 5 C d F   fnb f nb nb      2 F p d / 4 n / 2 nb max p p                M F d / 2 2 2 d d l   frbe frbe rbe           rbe oil rbe rbe F d l   frbe rbe rbe oil      c c P M frbe frbe rbe rbe J.B. Heywood - Internal Combustion Engine Fundamentals , 1st ed., McGraw-Hill, Inc., New York, 1988. STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP - Heat transfer - Dissipated thermal power - Conduction & convection -              W T T S h W T T S / s / k conv wall _ ext env wall _ ext wall _ ext cond wall _ int wall _ ext wall _ int wall wall        Nu h l / k f Re , Pr wall _ ext wall _ ext wall _ ext env wall _ ext env  1 / 4 0 . 67 Ra   wall _ ext Nu 0 . 68   wall _ ext 4 / 9    9 / 16 1 0 . 67 Pr env K.A. Brucker, J. Majdalani - Effective thermal conductivity of common geometric shapes , Int. J. Heat Mass Transf. 48 (2005) 4779 – 4796 . STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Selected physical models & field functions - • Eulerian Multiphase → Volume Of Fluid (immiscible fluid mixtures) • Segregated Multiphase Temperature Oil • k- ε Turbulence Air • Oil thermo-physical properties function of temperature and pressure Monitoring field functions        T V VF  cell cell cell _ air air   T     tot _ air V VF cell cell _ air air        T V VF  cell cell cell _ oil oil   T     tot _ oil V VF cell cell _ oil oil STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Moving mesh - - Morphing (piston motion) - - Overset mesh (rod motion) - STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Temperature - Oil Air STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP Oil – Oil fraction & Air Dynamic Viscosity - STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Velocity - Oil Air STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP Different oil levels … High oil level Std. oil level Low oil level Oil Air STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP … and various operating conditions - High oil level, High oil level, High oil level, 800 rpm 1000 rpm 1200 rpm Std. oil level, Std. oil level, Std. oil level, 800 rpm 1000 rpm 1200 rpm Low oil level, Low oil level, Low oil level, 1000 rpm 1200 rpm 800 rpm STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP … and various operating conditions - Oil Air High oil level, High oil level, High oil level, 800 rpm 1200 rpm 1000 rpm Std. oil level, Std. oil level, Std. oil level, 800 rpm 1000 rpm 1200 rpm Low oil level, Low oil level, Low oil level, 800 rpm 1000 rpm 1200 rpm STAR Global Conference 2014 - Vienna

D EPT . OF S CIENCES & M ETHODS FOR E NGINEERING – U NIV . OF M ODENA & R EGGIO E MILIA H YDRAULIC S YSTEMS D ESIGN R ESEARCH G ROUP – Work in progress - … Three pistons … Thank you very much for your kind attention! … From 2D to 3D … STAR Global Conference 2014 - Vienna