Professor Graham Pullan

Professor of Computational Aerothermal Design


Professor Graham Pullan is Co-Director of the Whittle Laboratory. He leads the EPSRC Centre for Doctoral Training in Future Propulsion and Power and is also the Cambridge Co-Director. He completed his PhD in 2001 at the Whittle Laboratory and has continued his research there - first as the Rolls-Royce/Trinity Hall Research Fellow (until 2008) and then as a member of the academic team. His research is focussed on the three-dimensional aerodynamic design of turbomachinery, and on the development of the computional methods required to achieve this. He has received: the 2012 ASME Gas Turbine Award; ASME IGTI Best Paper Awards in 2011, 2012, 2014, 2016, 2017 and 2018; the 2013 Rolls-Royce Howes Ruffles prize.

Research topics

Improvements to the aerodynamic performance of turbines and compressors are directly linked to reductions in the enviornmental impact of jet engines and power stations.

Accelerated computational analysis

The Turbostream flow solver has been written to run efficiently on the modern many-core processors found in graphics cards. These chips have hundreds of cores and Turbostream can utilise them to run an order magnitude faster than a traditional Computational Fluid Dynamics (CFD) code. This has a major impact on design where either the number of candidate blades, or the fidelity with which they are analysed, can be greatly increased.

dbslice is an interactive web-based post-processing tool for the analysis of large numbers of computations (or experiments). 

Compressor operability

Rotating stall limits the operation of compressors at low flow rates. In a collaborative project with colleagues at MIT's Gas Turbine Lab, computations and experiments were used to discover the origin and structure of the "spike-type" stall inception process.

At part-speed, flow is removed from the compressor to maintain stability. Research using a compressor rig (corroborated by CFD) has revealed the impact on compressor performance of removing air non-uniformly from the compressor circumference.

Novel turbine aerodynamic concepts

Conventional wisdom dictates that low aspect ratio (span-to-chord ratio) blades have a poor aerodynamic performance. A recent project using a novel "splitter blade" concept has shown that significant improvements can be made. 

Publications & updates

Modelling Turbine Acoustic Impedance

We quantify the sensitivity of turbine acoustic impedance to aerodynamic design parameters. Impedance boundary conditions are an influential yet uncertain parameter in predicting the thermoacoustic stability of gas turbine combustors. We extend the semi-actuator disk model to cambered blades, using non-linear time-domain computations of turbine vane and stage cascades with acoustic forcing for validation data. Discretising cambered aerofoils into multiple disks improves reflection coefficient predictions, reducing error by up to an order of magnitude compared to a flat plate assumption. A parametric study of turbine stage designs using the analytical model shows acoustic impedance is a weak function of degree of reaction and polytropic efficiency. The design parameter with the strongest influence is flow coefficient, followed by axial velocity ratio and Mach number. We provide the combustion engineer with improved tools to predict impedance boundary conditions.


J. Brind, G. Pullan


International Journal of Turbomachinery, Propulsion and Power



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Effect of Blade Row Interaction on Rotor Film Cooling

The mechanisms of blade row interaction affecting rotor film cooling are identified to make recommendations for the design of film cooling in the real, unsteady turbine environment. Present design practice makes the simplifying assumption of steady boundary conditions despite intrinsic unsteadiness due to blade row interaction; we argue that if film cooling responds nonlinearly to unsteadiness, the time-averaged performance will then be in error. Nonlinear behavior is confirmed using experimental measurements of flat-plate cylindrical film cooling holes. Unsteady computations are used to identify the blade row interaction mechanisms in a high-pressure turbine rotor, and a quasi-steady model is used to predict unsteady excursions in momentum flux ratio. It is recommended that the designer should choose a cooling configuration that behaves linearly over the expected excursions in momentum flux ratio as predicted by a quasi-steady hole model.


J. Brind, G. Pullan


Journal of Turbomachinery



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Loss in Axial Compressor Bleed Systems

A new method for characterising bleed system loss is introduced, using research compressor test results as a demonstration case. A loss coefficient is defined for a control volume including only flow passing through the bleed system. The coefficient takes a measured value of 95% bleed system inlet dynamic head, and is shown to be a weak function of compressor operating point and bleed rate, varying by +/-2.2% over all tested conditions. This loss coefficient is the correct non-dimensional metric for quantifying and comparing bleed system performance.


S.D. Grimshaw, J. Brind, G. Pullan, R. Seki


Proceedings of ASME Turbo Expo 2019

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