Overview
Oil consumption by aero-engines is a major concern for both ecological and autonomy reasons. The air-oil separation technologies (de-oiler and de-aerator) have been long time inherited from past generation engine architectures. Based on current oil system requirements (oil consumption, mass, compactness, reliability) and technologies (brush and lift carbon seals), ULB-ATM and his partners developed hardware for advanced oil separation equipment, built them and tested them to validate the technology. These tests require also the development of specific instrumentation and measurement devices in order to characterise properly the equipment.
The partners will more specifically perform the following activities:
- Design and test a centrifugal blower (order of magnitude of the working point: air flow rate of 200 m3/h with a delta pressure of 10 kPa with a rotational speed of 12.000 RPM.
- Design and test a demonstration unit of an air quality measurement device. The measurement device should measure the low oil quantity (order of magnitude: 0,1 l/h) in an air flow (order of magnitude: 200 m3/h).
ULB-ATM adapted its current test benches for lubrication equipment to the new requirements imposed by this application. All tests will be performed with the double objective of validating the design of the lubrication components as well as characterizing their performance with the qualification requirements in mind.
ULB-ATM has already a full qualification of its test benches (obtained from Techspace Aero) for his "clean oil" lubrication test bench and his "polluted oil" lubrication test bench.
Funding
Results
Executive Summary:
Although aircraft gas turbines have evolved tremendously in recent years, the lubrication systems have remained largely unchanged. Lubricants are used in aero-engines to reduce friction and wear as well as for cooling and sealing. To meet requirements such as a lower aero-engine oil consumption, while maintaining reliability and lower mass, novel technologies are required.
The EU-funded project 'Test of advanced lubrication equipment' (LubSEP) addressed this challenge by developing an innovative engine oil system (lubrication system). This developed Pump And Separation System (PASS) integrates three critical functions of the aero-engine into a single system. These are the de-oiling and deaeration of the oil-air mixture generated in the engine bearing and the gearbox sumps as well as oil pumping back toward the oil tank.
De-oiling helps remove small oil droplets from the air flow. Poor de-oiling efficiency implies high engine oil consumption that limits flight endurance and increases oil tank weight and size as well as aircraft emissions.
The deaeration function of the scavenge oil removes air bubbles from the oil-air mixture returning to the tank. Poor deaeration efficiency raises problems with cooling and lubrication of the engine roller bearings.
Project partners have also successfully developed and tested a method that is based on radioactive traces to measure very small engine oil consumptions. A newly developed air blower located at the PASS outlet ensures sealing of the engine bearing chambers and efficient air suction through the whole air-oil separation system.
Use of the PASS will considerably simplify the aero-engine lubrication system. The reduction in number of components will lead to a much lighter and more reliable engine oil system. The innovation could also result in more efficient aero-engines that consume less oil and fuel – a boon for the aeronautics industry and the environment.