The Energy and Transport Research Centre at the School of Engineering and Mathematical Sciences is an internationally leading research centre in the field of fuel injection systems, two phase flows and in particular cavitation and fuel spray technology.
Test cells relevant to cavitation studies include: steady-flow rig for enlarged nozzle models where studies on various geometries are continuously contacted for all type of engines, a number of real-size fully transparent fuel injectors, fuel injection system characterization and performance rigs, test cells for long-term effects of cavitation on fuel properties, a dedicated test cell for studies on cavitation inception for various fuels, two test rigs for testing of cavitation erosion using ultrasound and two test rigs for visualisation studies in simplified nozzle orifices.
Special Equipment include: Laser Doppler Velocimetry (LDV & PDA), Particle Image Velocimetry (PIV), PLIF imaging system, Yag and Excimer lasers, Shadowgraph/Schlieren photography system, numerous high-speed video cameras and CCD cameras, LIF-based diagnostic system, 100s of transparent fuel nozzle replicas for all type of IC engines, steady flow refractive index matching rig, a CT scanner, microscopes for surface inspection and an accurate balance for weight precision measurements.
Within the Delft complex the University owns a cavitation tunnel and other flow facilities which are used for the study of hydrodynamic phenomena. Furthermore, the University has free access to MARIN’s high speed cavitation tunnel in Wageningen in The Netherlands. Typical of the recent work undertaken has been the study of the break-up of sheet cavities into vortex structures under the action of the re-entrant jet. This break-up phenomenon is a critical precursor to the understanding of cavitation erosion fracture processes: this criticality has been identified at both model and full scale.
The group at Loughborough University has developed in collaboration with Caterpillar and City University London as part of a DTI major project, which has for the first time measured optically both geometric and string cavitation in very high pressure (>2000 bar) fuel injection systems. The Dynamics Group has developed detailed multi-physics models that range from nano-scale applications to micro-scale tribology/rheology, and highlight the interplay between cavitation and tribology (including friction, wear and erosion).
These encompass, surface energy effects, intermolecular interactions, formation of menisci, hydrodynamics and elasto-hydrodynamics for devices from micro-electromechanical systems to elastomeric seals and IC engine and bearing tribology. A new model providing a fundamental explanation of surface film distribution, cavitation and reformation has just emerged, where the underlying cause of cavitation and the ensuing lubricant mogul phenomenon is expounded.