Experimental Aerothermal Study of Internal Jet Engine Structures
Doctoral thesis, 2021

In commercial aviation, efficiency improvements may be gained by aerodynamic optimisation of its structural components, such as the intermediate compressor duct (ICD) and the turbine rear structure (TRS). These components have frequently been overlooked in favour of compressor and turbine module optimisation. This means that publicly available information on these structural components is relatively sparse, even though such components may offer substantial weight reduction and, with the introduction of hydrogen as aviation fuel, novel synergistic component integration.

This thesis presents heuristic solutions to meet modern demands for verification data on two commercial aviation engine components, the ICD and TRS. The work spans separate research projects and addresses both method development and test facility design.

The development of two measurement methods is presented. First, detailed uncertainty analysis of multi-hole probe implementation in the TRS has led to a 50\% reduction in uncertainty regarding total pressure measurement. Furthermore, a modern approach to measuring convective heat transfer has been developed and implemented on the outlet guide vane in the TRS. Neither of the two approaches presented here is limited to applications in the TRS or ICD and may be used in other applications. The aerothermal performance of the TRS for two different Reynolds numbers, several flow coefficients and three different surface roughness numbers have been investigated, and novel results on transition location, streamlines, heat transfer and loss distribution are presented. The second part of the thesis describes the design of a new, low speed, 2.5 stage low-pressure compressor (LPC) facility, built to investigate novel concepts of hydrogen integration in the ICD. Methods developed in the TRS are adopted and implemented in the new facility. A pre-study of the LPC and ICD instrumentation shows that compressor performance may be measured with better than 1% uncertainty using gas path studies.

Disclaimer: The content of this article reflects only the authors’ view. The Clean Sky 2 Joint Undertaking is not responsible for any use that may be made of the information it contains.

intermediate compressor duct


laminar-turbulent transition


turbine rear structure

heat transfer

hydrogen propulsion


uncertainty analysis

Clean Sky 2 Joint Undertaking European Union (EU) Horizon 2020 CS2-RIA EATEEM 82139

multi-hole probe

Vasa B
Opponent: Prof. Thomas Povey, Dept of Engineering Science, University of Oxford,


Isak Jonsson

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Surface roughness impact on secondary flow and losses in a turbine exhaust casing

Proceedings of the ASME Turbo Expo,; Vol. 2B-2018(2018)

Paper in proceeding


Proceedings of the ASME Turbo Expo,; (2019)

Paper in proceeding

Infrared Thermography Investigation of Heat Transfer on Outlet Guide Vanes in a Turbine Rear Structure

International Journal of Turbomachinery, Propulsion and Power,; Vol. 5(2020)

Journal article

Design of Chalmers new low-pressure compressor test facility for low-speed testing of cryo-engine applications

14th European Conference on Turbomachinery Fluid Dynamics and Thermodynamics, ETC 2021,; Vol. 14(2021)

Paper in proceeding

Design and pre-test evaluation of a low-pressure compressor test facility for cryogenic hydrogen fuel integration

Proceedings of the ASME Turbo Expo,; Vol. 2A-2021(2021)

Paper in proceeding

Feasibility Study of a Radical Vane-Integrated Heat Exchanger for Turbofan Engine Applications

Proceedings of the ASME Turbo Expo,; Vol. 7C(2020)

Paper in proceeding

One mitigation path to reduce carbon emissions from the aviation industry is to improve the propulsion system. i.e., the engines. Modern engines in commercial aircraft are extraordinarily sophisticated, safe, and efficient machines, and improving them requires an enormous engineering effort and capital investment.

This work aids the engineering effort by investigating the impact of novel alterations of the internal jet engine structures (large structures inside the core of the jet engine). The focus is on measuring the aerothermal performance of conventional and novel hydrogen-fuelled engines. Aerothermal is the science of heating or cooling a surface due to contact with a fluid that is highly relevant for applications with high thermal loads such as turbomachinery.

Experimental investigations of components in turbomachinery comes with several challenges. An accurate representation of the flow in laboratory conditions frequently requires facilities of several metric tons and thousands of parts to be constructed. Furthermore, the fluid and thermal loads inside the facilities are generally challenging to access and accurately measure. This is addressed by presenting a recently finalised test facility, improved aerothermal measurement methods and novel experimental results. The new facility, methods and findings provide insights into aerothermal loads in the internal jet engine structures and assist the engineering effort for future aviation engines.

Enabling cryogenic hydrogen-based CO2-free air transport (ENABLEH2)

European Commission (EC) (EC/H2020/769241), 2018-09-01 -- 2021-08-31.

Experimental Aero- and Thermal investigation for a next generation Engine Exit Module (EATEEM)

European Commission (EC) (EC/H2020/821398), 2018-10-01 -- 2021-03-31.

MOTSTROM - Drag reduction on aerodynamic surfaces

VINNOVA (2014-00897), 2014-07-01 -- 2017-06-30.

AT3E - Aerotermoutveckling för effektiva jetmotorutlopp

VINNOVA (2017-04861), 2017-11-10 -- 2022-06-30.

Subject Categories

Aerospace Engineering

Applied Mechanics

Fluid Mechanics and Acoustics


Chalmers Laboratory of Fluids and Thermal Sciences



Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5049



Vasa B


Opponent: Prof. Thomas Povey, Dept of Engineering Science, University of Oxford,

More information

Latest update

6/3/2022 2