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

Importance of Nonequilibrium Modeling for Compressors

This paper investigates the importance of nonequilibrium boundary-layer modeling for three compressor blade geometries, using RANS and high-fidelity simulations. We find that capturing nonequilibrium effects in RANS is crucial to capturing the correct boundary-layer loss. This is because the production of turbulence within the nonequilibrium region affects both the loss generation in the nonequilibrium region, but also the final equilibrium state. We show that capturing the correct nonequilibrium behavior is possible by adapting industry standard models (in this case the k-omega SST model). We show that for the range of cases studied here, nonequilibrium effects can modify the trailing-edge momentum thickness by up to 40% and can change the trailing-edge shape factor from 1.8 to 2.1.

Authors:

Spencer, Robert ; Przytarski, Pawel; Adami, Paolo

Publication:

Journal of Turbomachinery

DOI:

DOI10.1115/1.4054813

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Unsteady Structure of Compressor Tip Leakage Flows

Direct numerical simulations (DNS) are performed of a cantilevered stator blade to identify the unsteady and turbulent flow structure within compressor tip flows. The simulations were performed with clearances of 1.6% and 3.2% of chord. The results show that the flow both within the gap and at the exit on the suction side highly unsteady phenomena controlled by fine-scale turbulent structures. The signature of the classical tip-leakage vortex is a consequence of time-averaging and does not exist in the true unsteady flow. Despite the complexity, we are able to replicate the flow within the tip gap using a validated quasi-three-dimensional (Q3D) model. This enables a wide range of Q3D DNS simulations to study the effects of blade tip corner radius and Reynolds number. Tip corner radius is found to radically alter the unsteady flow in the tip; it affects both separation bubble size and shape, as well as transition mechanisms in the tip flow. These effects can lead to variations in tip ma

Authors:

Maynard, JM ; Wheeler, APS ; Taylor, JV ; Wells R

Publication:

Journal of Turbomachinery

DOI:

DOI10.1115/1.4055769

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Desktop DNS : an open toolkit for turbomachinery aerodynamics

The prevailing view is that high fidelity simulation, particularly DNS (direct numerical simulation), is not something for the practical turbomachinery aerodynamicist — requiring too much computational and personal effort to make it worth it. The aim of the ‘Desktop-DNS’ toolkit described in this paper is to change this by greatly lowering the barrier to entry for running DNS. The paper shows how, using an efficient high-order Navier-Stokes computer code, it is becoming increasingly possible to solve testcases of industry relevance with high fidelity LES and DNS, making use of the latest advances in single compute node performance. This is achievable using both efficient algorithms and GPU acceleration. The paper will use a compressor blade testcase to illustrate how, in some cases, high-fidelity simulations can be performed at relatively low costs on a small number of computer nodes. This raises the possibility of a much more widespread use of DNS to inform early design choices, enhan

Authors:

Andrew P. S. Wheeler

Publication:

Proceedings of the ASME Turbo Expo 2023

DOI:

doi.org/10.1115/GT2023-102647

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Career opportunities

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