• Login
• Admin

Jamil Muhammad, Mahmud (2024) Numerical simulation of novel flow control strategies for a vertical stabiliser. PhD thesis, University of Nottingham.

Preview

PDF (Thesis - as examined) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader Available under Licence Creative Commons Attribution. Download (15MB) | Preview

Abstract

The flow control strategy is crucial in aerodynamics, especially in studying laminar to turbulent boundary layer separation. It also contributes to enhancing the side force coefficient and reduction of drag force coefficient. The vertical tailplane is a significant part of an aircraft's structure, providing directional control and stability. To improve the directional control and stability of the vertical tailplane, this project aims to investigate a new strategy of flow control devices using rudder-mounted slat and leading-edge undulation. The study numerically investigates the effect of separation using a Reynolds Number of 1.69 × 105.

The study compared various turbulence models and high-fidelity large eddy simulation (LES) for baseline with zero rudder deflection. The transition k-kl-ꞷ model and LES produced better predictions, proving robustness in predicting transition-related flow. The experimental data is used to validate the turbulence models and LES results for drag and side force coefficients. The comparison shows that all turbulence models can accurately predict the side force and drag force coefficients when the flow is attached and at lower sideslip angles. In addition, the S-A turbulence model performed better than all the turbulence models except the transition k-kl-ꞷ model in predicting the force coefficients.

Also, this study investigates the aerodynamic effect of a rudder-mounted slat on a vertical stabiliser. The numerical results showed that the side force coefficient increased by up to 4% while the drag coefficient was unchanged when the rudder deflection angle was set to δ = 30°. LES results suggested that the rudder-mounted slat can increase the circulation around the vertical stabiliser, showing that the flow from the upstream recirculating regions was drawn towards the rudder surface. Associated changes in the turbulent flow field, including the mean and turbulent flow field and the vortical structure, are also presented to help understand the flow control mechanism by the rudder-mounted slat.

Lastly, the impact of the leading-edge undulation at rudder deflection δ = 30° and sideslip angle of β = 8°, which aimed to enhance aerodynamic performance and reduce separation, was investigated. The numerical results of the modified and baseline configurations were compared using velocity and streamlines at the lower, peak, and upper trough regions. These regions of the modified single bump were found to show additional flow attachment compared to the baseline. Notably improving aerodynamics around peaks and troughs, this design showcased enhanced aerodynamic performance and favourable flow characteristics on the vertical tailplane.

Item Type:	Thesis (University of Nottingham only) (PhD)
Supervisors:	Choi, Kwing-So Wang, Yaxing
Keywords:	Aerodynamics; Boundary layer separation; Vertical tailplane; Flow control; Undulation; Turbulence models; Rudder-mounted slat
Subjects:	T Technology > TL Motor vehicles. Aeronautics. Astronautics
Faculties/Schools:	UK Campuses > Faculty of Engineering > Department of Mechanical, Materials and Manufacturing Engineering
Item ID:	79813
Depositing User:	Muhammad, Mahmud
Date Deposited:	31 Oct 2024 14:55
Last Modified:	10 Dec 2024 04:40
URI:	https://eprints.nottingham.ac.uk/id/eprint/79813

Actions (Archive Staff Only)

Edit View