This study systematically compares the aerodynamic characteristics of four FIFA World Cup official footballs, including the 2026 ball Trionda, using wind tunnel measurements and simplified trajectory analysis. Drag coefficients and time-resolved side and lift forces were measured over flow speeds of 7–35 m/s (Re ≈ 1.1 × 10⁵–5.2 × 10⁵). Unsteady aerodynamic behaviour was quantified using both root-mean-square (RMS) values and power spectral density (PSD) analysis. In addition, the influence of panel orientation was assessed through an additional configuration for Trionda. All balls exhibited a drag crisis, with Trionda showing the lowest critical Reynolds number (≈ 1.78 × 10⁵), followed by Al Rihla, Brazuca, and Telstar. In the supercritical regime, Trionda exhibited a consistently higher drag coefficient (≈ 0.22). PSD results revealed broader spectral energy and enhanced fluctuations for Trionda compared with Al Rihla, indicating increased wake unsteadiness. Orientation effects introduced measurable but limited variation without altering the overall aerodynamic trends. Simplified trajectory simulations indicate shorter flight distances for Trionda at high speeds, reflecting its higher drag. These results provide a physically consistent baseline for comparing ball aerodynamics under controlled conditions and offer insight into potential variations in ball flight behaviour under match-relevant conditions.
Asai et al. (Sun,) studied this question.