Accurate Aerodynamic Measurement in Unsteady Flow

Flows in turbomachinery are inherently unsteady, e.g. when measuring downstream of rotating turbine blades. Standard practice to measure the flow angle, the flow velocity and the "stagnation" pressure of the flow (i.e. the pressure when the flow is brought to rest) is to use steady probes, with the assumption that they provide accurate time-averaged flow quantities. This data is often sufficient, e.g. to calculate the turbine efficiency.
Recent work [1] has highlighted flaws in this approach. This project will address the problem by developing novel probe concepts that avoid bias errors in unsteady flow. The development of new probe designs will include novel studies on probe roughness effects and numerical + experimental comparison of probe geometries. It is expected that the novel research work will result in publication of several articles.
[1] J. D. Coull, H. C. H. Ng, T. Dickens, J. Serna, and K. Cengiz, "Pneumatic-Probe Measurement Errors Caused by Fluctuating Flow Angles," https://doi.org/10.2514/1.J062569, vol. 61, no. 7, pp. 2922-2931, May 2023, doi: 10.2514/1.J062569.
The key aims of the research
This project aims to test and develop these new probe concepts, so that they can be readily adopted across industry and academia. The key outcomes will be to:
1. Build scientific understanding of the aerodynamics of the new concept(s).
2. Explore the design space, to further optimise their performance.
3. Obtain detailed experimental validation of the benefits of the new probes.
The key objectives of the research
1. Understand the aerodynamics of the prototype probe in a well-characterised fluid flow.
2. Understand how to improve the design for measurement accuracy and manufacture.
3. Demonstrate a new probe in a high Technology-Readiness-Level (TRL) turbine facility, and quantify the benefits compared to current state-of-the-art measurements.
The approach that will be taken to answer these questions
The approach will focus on experimental measurements, which provide the ultimate proving ground for the new probes. The experiments will be complemented by Computational Fluid Dynamics (CFD) studies and analytical modelling. These will aid in the interpretation of the experimental data and help to build understanding of the design space.