Team

Prof. Andrew Wheeler

Professor of Aerothermal and Fluids Engineering

Biography

After obtaining my PhD on unsteady flows in compressors at Cambridge in 2007, I worked as the Rolls-Royce Research fellow at the Osney Laboratory, University of Oxford.

Following this post, I’ve worked at Queen Mary, University of London and Southampton University as a lecturer. I moved back to Cambridge University and the Whittle Laboratory in December 2014. As well as my role as a lecturer at the Engineering Department, I was an EPSRC Fellow from 2014-2019, and I am Fellow of St. John’s College.

Research topics

My research interests are focused on the thermofluid dynamics of turbomachines used in both aero-engine propulsion and land-based power.

I have published articles on a wide range of topics such as: unsteady flows in compressors; transonic turbine aerodynamics and heat transfer; Direct Numerical Simulation of turbomachinery flows; real-gas flows in Organic Rankine Cycle turbines.

I am studying how real-gas behaviour affects turbine performance, with application to the use of turbines for heat-recovery systems (such as Organic Rankine Cycles). The work is both experimental and computational. See here for more details.

I have developed a high-order code (3DNS), which is written specifically for time-accurate high-fidelity simulations (DNS/LES) of turbomachinery flows. The code is a 4th order accurate compressible Navier-Stokes solver which can also solve for real-gas (such as for Organic Rankine Cycles turbines).

Publications & updates

The Effect of Isentropic Exponent on Transonic Turbine Performance

The isentropic exponent is one of the most important properties affecting gas dynamics. Nonetheless, its effect on turbine performance is not well known. This paper discusses a series of experimental and computational studies to determine the effect of isentropic exponent on the flow field within a turbine vane. Experiments are performed using a newly modified transient wind tunnel that enables annular cascade testing with a wide range of working fluids and operating conditions. For the present study, tests are undertaken using air, CO2, R134a, and argon, giving a range of isentropic exponent from 1.08 to 1.67. Measurements include detailed wall static pressures that are compared with computational simulations. Our results show that over the range of isentropic exponents tested here, the loss can vary between 20% and 35%, depending on vane exit Mach number.

Authors:

David Baumgartner, John J. Otter, Andrew P. S. Wheeler

Publication:

Journal of Turbomachinery

DOI:

DOI: 10.1115/1.4046528

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The Effect of Non-Equilibrium Boundary Layers on Compressor Performance

The paper investigates the effect of non-equilibrium behaviour of boundary layers on the profile loss of a compressor. The investigation is undertaken using both direct numerical simulation (DNS) of a mid-height section of a compressor blade and a reduced order model, MISES. The solutions are validated using experimental measurements made in the embedded stage of a multistage low speed compressor. The paper shows that up to 35% of the suction surface boundary layer of the compressor blade exhibits non-equilibrium behaviour. The size of this region reduces as the Reynolds number is increased. The non-equilibrium behaviour was found to reduce profile loss in most cases, however, in a range of cases where transition occurs through a small separation the presence of non-equilibrium behaviour was found to increase profile loss.

Authors:

Andrew P. S. Wheeler, Anthony M. J. Dickens, Robert J. Miller

Publication:

Journal of Turbomachinery

DOI:

10.1115/1.4040094

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The Effect of Rotor Casing on Low-Pressure Steam Turbine and Diffuser Interactions

The present study aims to investigate the interaction between a last-stage steam turbine blade row and diffuser. This work is carried out using computational fluid dynamics (CFD) simulations of a generic last-stage low-pressure (LP) turbine and axial–radial exhaust diffuser attached to it. In order to determine the validity of the computational method, the CFD predictions are first compared with data obtained from an experimental test facility. A computational study is then performed for different design configurations of the diffuser and rotor casing shapes. The study focuses on typical flow features such as effects of rotor tip leakage flows and subsequent changes in the rotor–diffuser interactions. The results suggest that the rotor casing shape influences the rotor work extraction capability and yields significant improvements in the diffuser static pressure recovery.

Authors:

Gursharanjit Singh, Andrew P. S. Wheeler and Gurnam Singh

Publication:

Journal of Engineering for Gas Turbines and Power

DOI:

10.1115/1.4034417

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Career opportunities

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