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Orbiting Journal Bearing Experiment

Periodic Reporting for period 2 - AOrbit (Orbiting Journal Bearing Experiment)

Reporting period: 2018-09-01 to 2021-06-30

AORBIT will design, build and operate a test rig for journal bearings and process the data obtained to provide the most useful information possible to support the development of suitable bearing systems for high-performance, high-reliability and low-weight speed reduction gearboxes for ultra-high bypass ratio aero-engines of the future. Our overarching aim is to meet this requirement and additionally to propose engineering refinements where appropriate to enhance the development of such journal bearings for the context in light of lessons emerging from the experimentation.
In order to achieve the above main aim, our objectives are to:
• Assemble a complete set of requirements for the bearing testing.
• Determine what concept best meets the requirements of the project.
• Set out a comprehensive plan for the development of the main rig and identify the resources required to deliver to this plan.
• Develop detailed designs for the rig elements.
• Determine an appropriate instrumentation set and design the data-acquisition and control systems.
• Procure and quality-assure component parts required for the rig build.
• Assemble and commission the rig.
• Operate the rig(s) in standard nominal design conditions.
• Operate the rig over a wide range of possible in-service conditions including sets of Endurance and Extreme Load Tests.
• Assemble a final report.
WP1: Orbiting Journal Bearing Rig – Design
1.1: Requirements and the merits of the identified approaches were identified and reviewed. A simplified rig configuration was identified.
1.2: A review of parameters and their likely quantifiable measurements were considered. Facilities for the potential inclusion of Acoustic Emission measurement and the ability to start bearing rotation from a known angular position was included for consideration during later stages of the work.
1.3: The PDR which was held on 26th July 2017.
1.4: Preliminary work towards the CDR indicated that the outline rig design is capable of operation to cover the full range of expected conditions to match those of interest for engine applications. Three configurations at the same diameter were chosen to provide the most appropriate range for evaluation of the design parameters within a sensible testing programme.
1.5: The CDR discussion was held on 21st December 2017.
1.6: A full set of mechanical design detail drawings for all rig components produced to enable manufacture to take place.

WP2: Build and Commissioning
2.1: The controlled rig build has been established. All aspects of instrumentation and control were completed.
2.2: Due to other rig priorities and test cell availability it was necessary to procure a new drive system specifically for this rig. The configuration is very similar to existing systems and the designs have been re-used to maintain costs within budget. A consequence of this is that it will remove any conflicts between access limitations which would otherwise be caused by sharing facilities. This caused some delay in rig procurement, but provided a significant improvement in rig utilisation reducing the test programme duration.
2.3: Rig commissioning has been competed.
2.4: Sign off on the rig commissioning tests completed.

3.1 Preliminary Test Results - Commissioning of the rig has been completed including full measurement calibration, demonstration of the envelope of capability, demonstration of the level of control which is achievable.
3.2 Endurance Tests - An cyclic endurance test of 27 representative cycles giving a total running time of 13.8 hours has been completed. This was reported using the standard format software developed under deliverable 3.2.
3.3 Extreme Test Conditions - Extreme testing was carried out over a range of orbiting and bearing sliding speeds to explore an extensive area of the operational envelope. Each test consisted of steady rotational conditions whilst the oil flow was systematically stepped down.

4.1 The report on the outcomes from the Experiment - This Task was completed in the form of the results from T3.1 to T3.3 and a python script that generates results in a report form was created. This is in line with the description of the work package given above.

WP5: Management and Dissemination
5.1: Deliverables were all submitted by the project management team and approved.
5.2: Management of the finances for the AOrbit project was completed, and information was managed for financial claims and audits.
5.3: The risk register was continually monitored and updated as necessary.
AOrbit will allow Europe to develop the capabilities needed to underpin the development of the next generation of aero and other gas turbine engines with smaller, hotter cores, employing architectures and technologies such as Ultra High Bypass Ratios (UHBR) including power gearboxes based on the AOrbit innovations that will deliver the performance improvements and reliability that will be demanded in the future. By supporting these developments the project will assist European aircraft manufacturers in maintaining their market share in the wide-body market (worth ca $275bn), and in due course also in the critical narrow-body market (worth ca $350bn 2012-2013).
UNOTT has a strong track record of working with the energy industry, and the facility will broaden that work to include the industrial gas turbine market, and so bring wider benefits to the UK and European economy. It is noted that “the face of power generation in the UK is set to change over the next few years as the need to replace obsolete plants, meet greenhouse gas emission and other environmental targets, and to provide security of energy supplies” . Clearly a need exists in the industrial gas power sector to reduce the cost of the product to remain competitive against other forms of power generation (renewable and nuclear) and other markets (notably in Asia). Therefore, a requirement to revise and simplify the designs of these systems exists. Technological areas where such revision is needed include transmissions and dynamics issues, as well as lubrication and cooling. KPMG, in a review of the energy sector, also recognise this requirement for technological development, and argue the need for investment of around £200bn in energy infrastructure over the next 10 years . In the UK in particular this means better supporting R&T and R&D activities .
Gas turbine performance has shown continuous strong improvement over the years since 1950. This is continuing with corresponding rise in the operating temperatures, pressures (OPR heading towards 80) and shaft speeds (heading for up to 30,000 rpm). The current ACARE 2020 and Flightpath 2050 environmental targets and the continuing need for gas turbine manufacturers to offer the best possible Specific Fuel Consumption (SFC) will continue to drive these trends upward for the aerospace sector. To respond to commercial needs and commercial pressures, but also to remain competitive against its main American rivals, Rolls-Royce have recently announced two new engines, Advance and UltraFan™ , the latter a geared turbo-fan engine. Looking longer term, the prospect of an even more fuel efficient engine architecture, the Open Rotor Design (ORD) has been developed in Clean Sky and is due to be flight tested in Clean Sky 2.
Rig Hardware Commissioning