本研究基於計算流體力學（CFD），針對配備螺旋槳動力之Slingsby T-67 Firefly教練機進行了三維全機流場分析。透過幾何建模、多尺度網格劃分，以及引入分離渦流模擬（IDDES）等高逼真度紊流模型，並獲得了以下學理與結論。
第一是數值模型與驗證之可靠性，在進入全機模擬前，本研究藉由NLF-Mod22(B) 翼型之螺旋槳干擾實驗數據進行了軟體驗證。結果顯示，所建立的 CFD網格與k–ω SST 紊流模型能精確捕捉螺旋槳滑流對機翼上、下表面壓力係數分布的不對稱影響，且升力係數之計算結果與實驗數據高度吻合。此外，數值模擬之表面流線亦精準重現了油流實驗中觀察到的滑流邊界發散與前緣擴展現象，證實本數值模型具備高度的物理逼真度。
第二是螺旋槳效應對全機之氣動干擾，全機分析結果指出，螺旋槳滑流的強烈切向速度會明顯改變主翼局部的有效攻角。在螺旋槳的上升葉片側，上洗氣流使局部攻角加大，產生較高的前緣負壓峰值與升力；反之，下降葉片側則受下洗氣流影響而使升力減弱。同時，滑流所帶來的高動壓特性，在高攻角（如10.17 度）下能有效替機翼翼根處的邊界層注入動能，延遲氣流分離的發生。這解釋了螺旋槳滑流如何幫助飛機在大攻角姿態下維持部分附著流。
第三是高攻角下尾翼之非對稱負載，研究進一步發現，隨著飛機攻角的提升，螺旋槳尾跡核心受非對稱推力干擾而產生偏移。這股帶有強大滑流的尾跡撞擊垂直尾翼時，迫使氣流在尾翼一側產生加速繞流，形成較高的負壓區與逆壓梯度。該現象不僅會在教練機大攻角飛行時引發偏航力矩，還會進一步導致橫向穩定性降低。

This study presents a three-dimensional computational fluid dynamics (CFD) analysis of a propeller-driven Slingsby T-67 Firefly trainer. Utilizing high-fidelity turbulence models like Detached Eddy Simulation (DES), the research successfully evaluates the aerodynamic coupling effects of the propulsion system. The numerical model was validated using airfoil experimental data, accurately capturing the propeller slipstream's impact on pressure distribution. Full-aircraft simulations reveal that the slipstream drastically and asymmetrically alters the main wing's local effective angle of attack, increasing lift on the upwash side while reducing it on the downwash side. Additionally, the slipstream's high dynamic pressure energizes the wing root boundary layer at high angles of attack, delaying airflow separation and enhancing overall stall safety. Finally, the study highlights asymmetric loading on the empennage at elevated angles of attack. The deflected propeller wake strikes the vertical tail, generating severe adverse pressure gradients and a significant yawing moment. This necessitates continuous rudder correction from the pilot and ultimately degrades the aircraft's lateral stability.

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