Optimization of ski jumping in-run posture using computational fluid dynamics

Area of Science:

• Sports Biomechanics
• Aerodynamics
• Computational Fluid Dynamics

Background:

• Aerodynamic optimization in ski jumping primarily focuses on the flight phase.
• The in-run phase's posture-fluid interactions and drag dynamics are less understood for speed maximization.

Purpose of the Study:

• To investigate posture-dependent aerodynamic resistance during the ski jumping in-run phase.
• To identify key posture parameters influencing drag and optimize athlete positioning for acceleration.

Main Methods:

• Development of an athlete-specific 3D model for high-resolution computational fluid dynamics (CFD) simulations.
• Systematic analysis of four critical posture parameters: torso attack angle (α), thigh attack angle (β), ankle joint angle (γ), and hip abduction angle (ε).

Main Results:

• Torso attack angle (α) was identified as the dominant factor influencing aerodynamic resistance during acceleration.
• An optimized posture configuration reduced cumulative air resistance by approximately 5% compared to conventional postures.
• Marginal adjustments in torso positioning significantly impacted drag reduction more than other joint angles.

Conclusions:

• Minimizing drag, not maximizing lift, is the primary objective for in-run optimization in ski jumping.
• Findings support evidence-based posture guidelines and a shift towards physics-driven training methodologies.
• CFD is a valuable tool for quantifying subtle posture adaptations in sports biomechanics and equipment optimization.