Multi-fidelity Aerodynamic Analysis of Outboard Horizontal Stabilizers for Small-scale Aircraft
Date
2024-12-18
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Abstract
The Outboard Horizontal Stabilizer (OHS) configuration is a unique fixed-wing design often used when a traditional tail is impractical and has been proposed as a means to achieve enhanced range and endurance. This study utilized a mixture of numerical approaches to quantify and critically examine the potential performance gains of the OHS concept. A modified non-linear lifting-line approach incorporating wing interactions was used for a fast low-fidelity model, and Reynolds Averaged Navier Stokes simulations were completed using OpenFOAM. A representative small-scale wing-tail combination was arranged into traditional, outboard, split, and extended span configurations and was used as a case study. The results obtained in this work demonstrate a substantial increase in Cl/Cd and Cl^{3/2}/Cd ratios for the OHS when compared to configurations with a similar main wing span, correlating to increased range and endurance, respectively. However, it was observed that simply extending the main wing to the overall span of the OHS configuration yielded higher performance. The importance of performing an aerodynamic analysis while considering static stability and trim is also discussed in detail. Furthermore, the specific conditions that can lead to increased overall lift and reduced induced drag on the stabilizers are highlighted and discussed using different approaches, and a qualitative analysis of the wake flow field was used to explain and confirm conclusions. Finally, a focused parametric study was performed to analyze how stabilizer position and deflection impact aerodynamic performance. It was found that for a fixed tail arm, having the tail just outboard of the main wing would maximize the performance of an OHS configuration. It was further found that the lift-to-drag ratio of an OHS configuration may surpass that of a conventional configuration with the same overall span if the fraction of tail span is reduced while increasing the tail arm, in order to maintain stability. Future studies will focus on a comprehensive optimization analysis to examine when and how OHS configurations may outperform optimal conventional configurations.
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Keywords
Outboard Horizontal Stabilizer, CFD, LLT, Induced drag
Citation
De Alwis, A. (2024). Multi-fidelity aerodynamic analysis of outboard horizontal stabilizers for small-scale aircraft (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.