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Alexander van Zuijlen

Publications and source records attributed to Alexander van Zuijlen.

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Patagium and tail morphology shape aerodynamic performance and control authority in gliding-mammal-inspired wings

Gliding mammals exhibit diverse patagium and tail/uropatagium morphologies that may influence aerodynamic performance and maneuverability. Here, we use computational fluid dynamics to isolate the aerodynamic effects of representative gliding-mammal-inspired morphologies under controlled flow conditions. Three patagium configurations were compared to evaluate the effects of membrane outline on lift generation, drag, stall behavior and pitching moment. Three tail/uropatagium configurations were further tested under baseline, symmetric-deflection and asymmetric-deflection conditions to assess their longitudinal and lateral control authority. The results show that a broader patagium configuration generated the highest lift and lift coefficient, whereas an intermediate patagium morphology showed a smoother post-stall response with lower drag. For the tail configurations, the colugo-like integrated uropatagium enhanced lift and pitch-control authority under symmetric deflection, while the flat-tail configuration produced stronger rolling and yawing responses under asymmetric deflection. These findings indicate that gliding-mammal-inspired morphologies produce distinct aerodynamic trade-offs rather than a single optimal design. The results provide insight into the functional diversity of gliding mammal morphology and offer design guidance for bioinspired morphing aerial robots.

physics.flu-dyn

Toward Meshless Turbulent Flow Simulation: LES-Integrated Vortex Particle Method

Recent developments in vortex particle methods for simulating three-dimensional incompressible flows are presented. A lightweight, dynamic Large-Eddy Simulation model is tested, featuring a dynamic procedure that relies solely on Lagrangian information and requires minimal auxiliary computation to update the model constant. The method employs a high-order algebraic kernel which enables direct, analytical expressions for conservation laws, the strain-rate tensor, and quadratic velocity diagnostics. Viscous diffusion is modeled using the core-spreading technique. The particle method is assessed with respect to kinematics and the conservation of energy, helicity, and enstrophy in vortex ring and leapfrogging vortex ring scenarios, both unperturbed and perturbed. The results indicate that the kinematics and flow diagnostics are accurately captured using relatively sparse particle distributions, effectively resolving the dynamics of the unstable flow phase. However, after the onset of instabilities, the sub-grid-scale methodology becomes strongly dependent on particle regularization to stabilize the flow solution.

physics.flu-dyn