Numerical investigation of influence of nose part shape of a high-speed surface transport on aerodynamic characteristics

This paper presents a comprehensive numerical investigation of the influence of the nose geometry of a high-speed surface transport (HSST) on its aerodynamic performance. The study focuses on the role of longitudinal vortex structures generated by non-streamlined nose shapes and their impact on drag, lift, and pitching moment. The unsteady three-dimensional Reynolds-averaged Navier-Stokes (URANS) equations, closed with the k-ω SST turbulence model, are employed to simulate the flow. The numerical methodology is based on the control volume approach with an implicit scheme, solved using the GMRES method with ILU preconditioning. A series of parametric studies is conducted to evaluate the effects of the nose length, width, and height relative to the track structure. The results demonstrate that the formation and evolution of longitudinal vortices significantly influence the aerodynamic characteristics of the vehicle. It is shown that increasing the nose length and height leads to a reduction in aerodynamic drag due to the weakening of transverse flow separation and more stable vortex structures in the wake. Conversely, increasing the nose width intensifies flow separation and enlarges the turbulent wake, resulting in higher drag coefficients. The study also reveals that, regardless of the geometric configuration, the HSST experiences a negative lift force, contributing to improved stability by pressing the vehicle toward the track, and a positive pitching moment. Variations in geometric parameters affect the magnitude of these forces through changes in pressure distribution and vortex intensity. In particular, the location and strength of low-pressure regions under the vehicle play a key role in determining lift and moment characteristics. The findings highlight the potential of controlled vortex generation as an effective approach to aerodynamic optimization. The developed numerical methodology and obtained results can be applied to the design and optimization of high-speed transport systems, including magnetically levitated vehicles.