Effect of Hybrid Laminar Flow Control Parameters on Vertical Tail Transition Location

The frictional resistance of laminar flow is approximately one order of magnitude lower than that of turbulent flow. Utilizing extensive laminar flow regions on wings and vertical tails can significantly reduce aerodynamic drag. This study investigates the impact of hybrid laminar flow control (HLFC) parameters including suction area and suction coefficient on transition location of a high-subsonic vertical tail. Based on the findings, optimal HLFC parameters were identified. Additionally, the influence of flight altitude and velocity on laminar flow retention was analyzed. Key results indicate that: Without HLFC, the vertical tail with a large swept angle exhibits early transition at 2% chord length from the leading edge, primarily driven by crossflow (CF) stationary vortices. Optimal HLFC implementation near the leading edge extends the laminar flow region to 35–40% of the surface area. Under the same HLFC parameters, the transition factors of different Mach numbers are consistent, while there are slight differences in the laminar flow regions, whereas increasing Reynolds number causes the transition location to shift upstream.