Search

This paper describes the high temperature upgrade of the Engine Component AeroThermal (ECAT) facility, an established engine-parts facility at the University of Oxford. The facility is used for high technology readiness level research and development, new technology demonstration and for component validation. The current facility has a modular working section which houses a full annulus of engine nozzle guide vanes (typically HP NGVs from a large civil jet-engine, but reconfigurable for smaller core sizes) which can be run at engine conditions of Reynolds number, Mach number and coolant-to-mainstream pressure ratio. The facility has a combustor simulator, which is used for combustor-turbine interaction studies with either rich or leanburn temperature, swirl and turbulence profiles. The ECAT facility is capable of highly accurate measurements of capacity, aerodynamic loss, and metal effectiveness. The facility can operate in either semi-transient blow-down mode (typically used for capacity characteristics) or steady-state regulated mode (typically used for aerodynamic traversing). For metal effectiveness measurements, a coolant-to mainstream temperature ratio range of 1.00-1.28 can be achieved by heating the mainstream with two 1 MW heaters. Although ECAT can be run at very close to engine conditions, the limitation on temperature ratio capability leads to imperfectly matched specific heat capacity flux ratio and compressibility effects (ratio of recovery temperature ratio to coolant-to-mainstream temperature ratio). The development described in this paper (foreseen as a requirement when ECAT was developed) addresses this scaling mismatch. This paper is about the design and optimisation of increased temperature capability for the ECAT facility, a system which will increase the mainstream inlet temperature to 600 K (327 °C), allowing coolant-to-mainstream temperature ratio to be matched to engine conditions. This is desirable as it will allow direct validation of temperature ratio scaling methods in addition to providing closer engine similarity. This is a critical development for engine designers as it allows higher technology readiness level testing to be achieved than has previously been possible, providing a test bed in which all important non-dimensional parameters for aero-thermal behaviour can be exactly matched to engine conditions. The aim is reduced engine development times, by providing earlier and higher fidelity testing than has previously been possible. As the technology matures it is possible to foresee that engine development testing (as opposed to Pass-Off testing) may be avoided with a test vehicle of this type. To accurately predict the operating conditions of the facility, a low order transient thermal model was developed in which the air delivery system and working section are modelled as a series of distributed thermal masses. Nusselt number correlations were used to calculate convective heat transfer to and from the fluid in the pipes and working section. The correlation was tuned and validated with accurate and extensive experimental results taken from test campaigns conducted in the existing facility. This modelling exercise informed a number of high-level facility design decisions to be taken, and will provide an accurate estimate of the running conditions of the facility. We present detailed results from the low-order modelling, and discuss the key design decisions. We also present a discussion of challenges in the mechanical design of the working section, which is complicated by transient thermal stress induced in the working section components during start-up of the facility. This analysis is benchmarked with directly measured boundary conditions from the existing working section, scaled appropriately to upgraded facility conditions. The staged development of the ECAT test-bed allows robust component analysis during the design phase. The high-temperature core for the ECAT test-bed has unusually high TRL capacity for a research organisation, and it is expected that the development and underlying methodology will be of interest to both engine designers and the research community. The facility will contribute to accelerated development time of novel engine technology in addition to further enabling fundamental research to be carried out engine representative environments.

This paper reports on the latest phase of the development of a new rotating machinery sealing technology, which was a successful seal test in a high temperature steam test facility at TU Brauschweig in Germany. The “Aerostatic Seal” is a dynamic clearance seal that is capable of maintaining very small clearances with a rotor and has the potential for a wide range of rotating machinery applications. It has been developed in recent years at Durham University, UK, in collaboration with a major OEM, with a focus on steam turbine sealing, and has previously been reported on in a number of ASME Turbo Expo papers. Previous work has reported on the design tool, and two air test facilities; testing in steam addressed the effect of high temperature components and the working fluid, and was an opportunity to verify the design system. The seal is a development of a retractable gland seal and so in a low load condition it is retracted from the rotor with a large rotor clearance and then when the pressure ratio is sufficient moves to an operational small clearance. At its operational clearance the seal is capable of moving with rotor vibrations which means the design clearance can be smaller than any expected rotor movement. The benefits include a significant reduction in leakage when compared to conventional sealing technologies and also the ability to react to large transients or thermal growths caused by rapid changes in machine loads and speeds. The seal is shown to operate well in this environment and this work moves the technology closer to deployment in industry.

The successful demonstration of the “Aerostatic Seal” in a half scale rotating facility is described in this paper. The Aerostatic seal is a novel dynamic clearance seal specifically designed for steam turbine secondary gas path applications. The seal responds to radial rotor excursions, so a reduced clearance can be maintained compared to conventional labyrinth seal without damage to the seal. This enables increased turbine performance through reduced leakage and increased tolerance of turbine transient events typically found during start up. The seal is an extension of the existing retractable seal design already deployed in commercial steam turbines. The seal was tested in the Durham Rotating Seals Rig, which was developed specifically to test this device. The rig featured a rotor designed to run with large eccentricities to model high speed radial rotor excursions, and the seal was instrumented to measure the real time seal response to the rotor. The experimental campaign has conclusively demonstrated the ability of the seal to dynamically respond to the rotor position. The key result is that the seal is able to track the rotor position at high speed, and hence maintain a mean seal clearance that is lower than the rotor eccentricity. Overall this work marks a key milestone in the development of the Aerostatic Seal, and leads the way to testing in a steam environment and application in steam turbine plant.

The Good Practice Guidelines for the Assessment and Treatment of Adults with Gender Dysphoria is a publication of the Intercollegiate Committee of the Royal College of Psychiatrists. The overall goal of the Good Practice Guidelines is to provide clinical guidance for health professionals to assist transsexual, transgender, and gender nonconforming people with safe and effective pathways to achieving lasting personal comfort with their gendered selves, in order to maximize their overall health, psychological well-being, and self-fulfillment. This assistance may include primary care, gynaecologic and urologic care, reproductive options, voice and communication therapy, mental health services (e.g., assessment, counselling, psychotherapy), and hormonal and surgical treatments. The Good Practice Guidelines are based on the best available science and expert professional consensus. The Good Practice Guidelines articulate standards of care while acknowledging the role of making informed choices and the value of ...

This paper presents a series of experiments on the Aerostatic Seal, a dynamic clearance seal for steam turbine application first described at the 2015 ASME Turbo Expo (Paper Number GT2015-43471). This dynamic clearance seal moves with rotor excursions and so has the potential to deliver a smaller clearance than traditional seals. The concept is an extension of the retractable seal design which is widely used in existing steam turbines. The experimental program was carried out in a low cost static test facility using an aerostatic seal design. The seal exhibited a dynamic clearance response and will therefore respond to rotor excursions. 3D CFD was also used to aid the understanding of flow features not captured by the analytical design tool. Adjustments to both the design process and to future seal designs are proposed in the body of the paper. This paper therefore describes an experimental proof of concept for the aerostatic seal and paves the way for future development in rotating facilities.

Effective sealing in turbomachinery reduces the leakage flow bypassing the turbine blades and also reduces the losses where the leakage flow mixes with the primary flow. In general the clearance should be as small as possible but is limited by thermal and mechanical effects which vary with load. In recent years intermittent energy sources, particularly wind and solar, have appeared in greater numbers on the power network. As a consequence conventional power plants need to become more flexible to accommodate renewable energy generation. A sealing technology which can accommodate rapid changes in load and maintain seal performance would be a valuable development.This paper presents a novel seal design for steam turbines. The seal is designed to be capable of maintaining a smaller clearance than that of conventional labyrinth seals whilst allowing for dynamic movement with the rotor. The paper describes the seal concept and the analytic al work undertaken to demonstrate the concept. The seal design has also been tested in test facilities at Durham and the initial experimental results are included. They show that the concept works as intended.Copyright © 2015 by ASME and Alstom Technologie AG

This paper describes the design and optimization of an ‘air-curtain’ type seal using a fluidic jet to reduce tip leakage losses on a small high-speed single stage axial turbine device. The application will essentially demonstrate proof of concept for turbomachinery applications, opening the door for the development of future designs for applications in all scales of turbomachine. CFD is used to develop and optimize the seal design. The performance benefit from applying the new seal is predicted. These calculations illustrate the importance of accurately accounting for the effects of the sealing jet on shroud shear forces, in addition to leakage flow reduction, when determining the overall gain in turbine output power from the improved sealing. It is planned to validate the new seal design in full-scale turbine tests, during the next phase of the work.

Our objective was to develop clinical practice guidance for the evaluation of hirsutism in premenopausal women. The Skin Academy is led by an international interdisciplinary team of experts, and aims to use the latest scientific and clinical data in selected dermatological diseases, to promote awareness, education and best clinical practice, thus improving patient care. The Skin Academy is an international platform designed to drive and develop education and awareness programmes, and to transfer scientific knowledge in dermatology across Europe and wider geographical areas. Consensus was guided by systematic review and discussion of current clinical practice across Europe during several group meetings of The Skin Academy, supported by conference calls, and e-mail communications. The outcome of the discussions was an evaluation form to be used by the clinician to help evaluate a patient presenting with excessive hair growth. This round-table expert opinion consensus paper, and the Diagnostic Evaluation Form it contains, is presented for discussion by the wider dermatology community.