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An approach to the study of elasto‐plastohydrodynamic lubrication in the wire drawing process. Part 2: Theoretical predictions
Author(s) -
ElButsh A. M. A.,
EiBadrawy R. S.,
Mokhtar M. O. A.
Publication year - 1994
Publication title -
lubrication science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.632
H-Index - 36
eISSN - 1557-6833
pISSN - 0954-0075
DOI - 10.1002/ls.3010060305
Subject(s) - lubrication , lubricant , mechanics , materials science , newtonian fluid , non newtonian fluid , reynolds equation , adiabatic process , shear stress , work (physics) , isothermal process , flow (mathematics) , wire drawing , power law fluid , generalized newtonian fluid , mechanical engineering , thermodynamics , reynolds number , shear rate , engineering , rheology , composite material , physics , turbulence
The generalised Reynolds' equation for Newtonian and non‐Newtonian fluids, as applied to the wire‐drawing process, together with the plasticity and energy equations have been adopted in solving the elasto‐plastohydrodynamic lubrication problem in the wire‐drawing process. The equations have been solved numerically using a finite difference technique with Gauss‐Siedel iterative scheme to predict hydrodynamic behaviour and to correlate the forming parameters to the lubrication behaviour in an endeavour to find the optimum operating conditions for maximum precision and productivity. The effect of using either Newtonian or non‐Newtonian lubricants on the process parameters has been also studied, to predict the most suitable lubricant type. The results indicate that the increase in the flow behaviour index increases the pressure gradient in the work zone, with a consequential reduction in oil film thickness. Also the minimum film thickness is highly influenced by the drawing speed. It can be concluded that the isothermal solution renders lower drawing stress than the adiabatic solution. The maximum shear stress, and hence the power loss, increases with the increase in die convergence angle.