Publications

In this paper, a low order model for predicting performance of radial turbocharger turbines is presented. The model combines an unsteady quasi-three dimensional CFD method with multiple one-dimensional meanline impeller solvers. The new model preserves the critical volute geometry features, which is crucial for the accurate prediction of the wave dynamics and retains effects of the rotor inlet circumferential non-uniformity. It also still maintains the desirable properties of being easy to set up and fast to run.

This paper investigates the limitations of 2D linear unsteady aerofoil theory for modelling the unsteady gust response of tidal stream turbines. Accurate unsteady load prediction is required to determine turbine life. Current state of the art design codes in industry use a single model, based on Theodorsen’s theory, to predict the response to all types of gust. This paper shows that different types of gust require different types of model. Vortical gusts, such as due to turbulence and shear flows, should be modelled using a combination of Sears’ and Horlock’s theories. Pressure gusts, such as those caused by free surface waves, should be modelled using Loewy’s theory. The accuracy of these models is examined using numerical predictions. The range of gusts likely to occur at real tidal sites is also examined. In most likely situations, pressure gusts cause variations in loads which can be modelled quasi-steadily,but vortical gusts must be modelled using the combined Sears/Horlock theory

The performance of automotive turbocharger turbines has long been realized to be quite different under pulsating flow conditions compared to that under the equivalent steady and quasi-steady conditions on which the conventional design concept is based. However, the mechanisms of this phenomenon are still intensively investigated nowadays. This paper presents an investigation of the response of a stand-alone rotor to inlet pulsating flow conditions by using a validated unsteady Reynolds-averaged Navier–Stokes solver (URANS). The effects of the frequency, the amplitude, and the temporal gradient of pulse waves on the instantaneous and cycle integrated performance of a radial turbine rotor in isolation were studied, decoupled from the upstream turbine volute. A numerical method was used to help gain the physical understanding of these effects. A validation of the numerical method against the experiments on a full configuration of the turbine was performed prior to the numerical tool being

This paper describes an experimental and computational investigation into the influence of tip clearance on the blade tip heat load of a high-pressure (HP) turbine stage. Experiments were performed in the Oxford Rotor facility which is a 11 stage, shroudless, transonic, high pressure turbine. The experiments were conducted at an engine representative Mach number and Reynolds number. Rotating frame instrumentation was used to capture both aerodynamic and heat flux data within the rotor blade row. Two rotor blade tip clearances were tested (1.5% and 1.0% of blade span). The experiments were compared with computational fluid dynamics (CFD) predictions made using a steady Reynolds-averaged Navier-Stokes (RANS) solver. The experiments and computational predictions were in good agreement. The blade tip heat transfer was observed to increase with reduced tip gap in both the CFD and the experiment. The augmentation of tip heat load at smaller clearances was found to be due to the ingestion of

This paper describes an innovative, three-day, turbomachinery research project for Japanese and British high-school students. The project is structured using modern teaching theories that encourage student curiosity and creativity. The experience develops teamwork and communication and helps to break down the cultural and linguistic barriers between students from different countries and backgrounds. The approach provides a framework for other hands-on research projects that aim to inspire young students to undertake a career in engineering. The project is part of the Clifton Scientific Trust's annual UK–Japan Young Scientist Workshop Programme.

Obtaining measurements in the rotating frame of reference requires either real-time communication between the rotating and stationary frames, or temporary data storage in the rotating frame. Rotating telemetry systems must be low-noise and high-bandwidth, which is hard to achieve using traditional slip-ring arrangements, while using temporary data storage introduces synchronisation issues. In this paper, the use of wireless telemetry for real-time data acquisition is demonstrated for two applications: tidal turbine load control and large-scale turbine pressure measurements.