RESEARCH TEAM / INSTITUTE EXCELLENCE
TRIBOLOGY IN MICRO-ENGINES AND MICRO-TURBINES
ENGINEERING AND TECHNOLOGY
The scientific field of Tribology is part of the wider knowledge field of Surface Engineering. It studies the main concepts and the mechanisms that govern the relative movement of engineering systems and provisions.
The research work of three Greek researchers - faculty members of the National Technical University and the University of Patras – applies to the improvement of the operating bearings of micro-engines and micro-turbines, contributing to the increase of the load carrying capacity, with the parallel reduction of friction losses.
This particular research has won an honorable award by the American Society of Mechanical Engineers at the «ASME Turbo Expo 2010» conference for its contribution to the improvement in the performance of the micro-engines and micro-turbines.
Research work in the micro-tribology field: Optimization of micro-bearings with artificial surface texturing
OPTIMIZATION OF GEOMETRY MICRO-THRUST BEARINGS WITH DESIGNED ARTIFICIAL TEXTURING
The aim of the project has been the optimization of geometry micro-thrust bearings with designed artificial texturing. In this particular case, the methodology used is based on the numerical solution of fluid mechanics equations (Navier-Stokes equations), combined with the use of optimization algorithms (evolutionary algorithms, combined with local search methods).
The bearings are modeled as micro-channels, consisting of a moving and a stationary wall. The moving wall (rotor) is assumed smooth, while part of the stationary wall (stator) has got artificial surface texturing with periodic dimples of trapezoidal form. The extent of the textured part of the stator and the dimple geometry are defined parametrically. In the optimization problem, the function to be maximized is the non-dimensional load carrying capacity. By solving the problem for parallel bearings, optimal trapezoidal geometries arise, for different values of the number of micro-dimples. All geometries are characterized by significant levels of load carrying. A further analysis shows that the resulting optimal geometries can increase significantly the load carrying capacity at non-parallel thrust bearings as well.
BEST PAPER AWARD BY THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS
The research work ‘Evolutionary Optimization of Micro-Thrust Bearings with Periodic Partial Trapezoidal Surface Texturing’ carried out by Dr. Christos Papadopoulos, Lecturer, Dr. Lambros Kaiktsis, Assistant Professor of the School of Naval Architecture and Marine Engineering of NTUA and Dr. Pantelis Nikolakopoulos, Lecturer of the Department of Mechanical Engineering & Aeronautics, at the University of Patras, was presented during the “ASME Turbo Expo 2010International conference (Glasgow, June, 2010) and won the best paper award by the Microturbines and Small Turbomachinery Committee of the American Society of Mechanical Engineers.
NATIONAL TECHNICAL UNIVERSITY
UNIVERSITY OF PATRAS
Pantelis Nikolakopoulos, (Lecturer),
Department of Mechanical Engineering & Aeronautics, University of Patras.