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Master thesis (2024)

Authors

I. Kiat Aerospace Engineering

Contributors

J. Sodja Group Sodja - Aerospace Engineering (supervisor 1)
Luca Marino Group Sodja - Aerospace Engineering (supervisor 1)
J.A. Melkert Flight Performance and Propulsion - Aerospace Engineering (supervisor 2)
A.H. van Zuijlen Aerodynamics - Aerospace Engineering (supervisor 2)
Faculty
Aerospace Engineering
More Info
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Published Date

29-04-2024

Language

English

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Faculty

Aerospace Engineering

Abstract

This thesis investigates a novel load alleviation technique known as mini-tabs, small devices placed on the upper surface of wings to reduce lift. Reynolds-Averaged Navier-Stokes (RANS) simulations were conducted to analyze the impact of geometrical properties on mini-tab performance in reducing the load on a wing.

The initial simulations focused on a single mini-tab, varying parameters such as height, aspect ratio, chordwise, and spanwise positions. Results indicate that increasing height or aspect ratio leads to decreased lift due to flow deceleration at the leading edge and expansion of the separated flow region downstream of the mini-tab. This will also increase the pressure drag. Increasing the height or aspect ratio also accelerates the flow at the lower surface, further reducing the lift generated by the wing.

Placing mini-tabs closer to the wingtip exhibits similar effects on lift reduction as increasing the height of the mini-tabs. This is because the relative height of the mini-tab with the local chord length increases when the mini-tab is positioned closer to the wingtip. A maximum lift reduction is also achieved when the mini-tab is placed at a 60% chordwise position.

Subsequent simulations explored the performance of multiple mini-tabs, revealing that orienting them orthogonal to the wind direction may not be optimal due to gap formation between the mini-tabs that energizes the wake downstream of the mini-tabs and reduces the reduction in lift. Conversely, aligning the mini-tabs with the leading edge has a higher efficiency in the reduction of the lift.

Overall, the findings suggest that mini-tabs offer a viable method for reducing wing forces and for load alleviation