Hydrodynamic & elastohydrodynamic lubrication
THD and TEHD analysis of journal, thrust and tilting-pad bearings with CFD, including conjugate heat transfer, cavitation (Elrod–Adams mass-conserving models) and deformable bearing shells.
National Technical University of Athens · Division of Marine Engineering
Marine Engineering & Tribology Group
We analyse, measure and optimise the machine elements that carry a ship’s power: thrust and journal bearings, stern-tube and crankshaft bearings, piston rings and the propulsion shafting. Our work combines CFD-based thermohydrodynamic (THD/TEHD) analysis, elasto-hydrodynamic modelling, large-scale laboratory experiments and onboard measurements.
1,457citations (Google Scholar, 2025)
23h-index (i10-index: 30)
80+journal & conference papers
15funded research projects
Friction, lubrication and dynamics in marine propulsion
In a large two-stroke powered vessel, mechanical losses in the engine amount to roughly 5–7.5% of brake horse power, journal bearings of the shafting add about 0.5–1% and the gearbox another 1–2%. For a typical Capesize bulk carrier this translates into an annual fuel bill of the order of €9.5 M — more than 90% of total running cost. Reducing friction, wear and vibration in these contacts therefore has a direct effect on fuel consumption, emissions and the availability of the ship.
The group works on this problem from both ends: predictive models that resolve the lubricant film, the thermal state of the bearing and the elasticity of its structure and foundation, and experimental facilities that can validate those models from the scale of a micro-thrust bearing up to a full-size shafting line.
- CFD thermohydrodynamic and thermoelasto-hydrodynamic bearing analysis
- Elastic shaft alignment including hull deformations and bearing film state
- Surface engineering: artificial texturing, hydrophobic and coated surfaces
- Shaft, hull and machinery vibration, monitoring and diagnosis
- Meta-model assisted, multi-objective design optimization
Research areas
Six connected themes, unified by the goal of quieter, more efficient and more reliable marine propulsion machinery.
Engine tribology
Piston rings, piston pin and crankshaft bearings of two-stroke and four-stroke marine diesel engines, with software developed in-house for the solution of the lubrication problem.
Shaft alignment & shafting interaction
Elastic shaft alignment that accounts for hull deformations, bearing foundation stiffness and the oil film — aligned with the latest BV and ABS rule guidance.
Propulsion-shaft & hull dynamics
Torsional, lateral and axial vibration of propulsion systems, hull vibration caused by engine and machinery operation, vibration mitigation and resonance assessment.
Surface engineering
Artificial surface texturing, hydrophobic and superhydrophobic stator surfaces, coatings and stochastic roughness — and their effect on load capacity and friction.
Optimization, AI & monitoring
Evolutionary, multi-objective and meta-model assisted optimization of machine elements; machine-learning based condition identification from sound, vibration and bearing data.
Featured project
i-MARINE — intelligent, adaptive-controllable shaft alignment
The project transformed a conventional propulsion shaft arrangement into an intelligent, controllable and adaptive system: an accurate digital twin of the shafting line, bearing and shafting monitoring procedures, small-scale experimental verification and finally an integrated monitoring platform installed on board.
Under this programme the group developed the numerical models behind elastic shaft alignment — bearing offsets, shaft elastic line and hull deflections — and studied the full shaft-line operating window to keep every bearing within acceptable loading.
Laboratory infrastructure
A tribometer suite, two large-scale bearing test beds, an instrumented shaft-alignment rig, onboard measurement capability and a 500-core computing cluster — all in the Machine Elements / Tribology Lab.
Work with us
We collaborate with classification societies, bearing and turbocharger manufacturers, ship owners and universities across Europe through research projects, consultancy studies and student theses. For shaft-alignment calculations and measurements, FEM/CFD analysis, vibration and acoustic measurements, engine–propeller matching and failure investigation, please get in touch.
Contact details & location Prof. Papadopoulos curriculum vitae →