Propeller-induced unsteady flow inside a model cooling duct of a hydrogen-electric aircraft
File(s)
Accepted version
Author(s)
Bryce-Smith, Toby
Buxton, Oliver RH
Papadakis, George
Steiros, Kostas
Type
Conference Paper
Abstract
The unsteady flowfield of a square duct immersed in propeller wake was characterised at two advance ratios using planar particle image velocimetry. Results show the ingestion and propagation of unsteadiness within cooling ducts typical of novel hydrogen-electric propeller aircraft propulsion systems. Two discrete structures, a root vortex and a portion of the vortex sheet, were ingested, creating a heterogenous flowfield within the entrance region characterised by a shear flow and skewed instantaneous velocity profile. Unsteady motions at the blade passing frequency are dominant through the first ten duct widths, typical of a nacelle's length scale, which decay into incoherent motions. A novel reenergising mechanism of energy at the blade passing frequency is observed within the duct and is hypothesised to be linked to blade wake pitch and shear flow magnitude, caused by variation of advance ratio and internal blockage. Results imply that this mechanism is highly sensitive to design variables (e.g. number of propeller blades) and to changing propeller settings (e.g. advance ratio) across the mission profile. Additionally, results highlight the importance of unsteady measurements when considering propulsive system flows, especially when motions at coherent frequencies in the bulk flow may lead to increased time-averaged heat transfer yielding improved cooling or conversely, may lead to local overcooling that could damage a fuel cell.
Date Issued
2025-04-03
Date Acceptance
2025-04-03
Citation
2025
Publisher
French Aeronautics and Aerospace Society (3AF)
Copyright Statement
© 2025 French Aeronautics and Aerospace Society (3AF).
Source
59th 3AF International Conference on Applied Aerodynamics
Publication Status
Published
Start Date
2025-03-24
Finish Date
2025-03-26
Coverage Spatial
Strasbourg, France
Date Publish Online
2025-04-03