ANALYSIS OF THE INFLUENCE OF DIFFERENT VEHICLE BODY TYPES AND TRANSPORTED BICYCLES ON AERODYNAMIC PERFORMANCE

Abstract

This study investigates the influence of bicycles transported on passenger cars on airflow and aerodynamic characteristics, considering different vehicle body shapes and bicycle mounting locations. Three vehicle types were selected as the research object: a sedan, a station wagon, and an SUV, with bicycles mounted either on the roof or at the rear of the vehicle. The research was conducted using Computational Fluid Dynamics (CFD) methods, which enabled a detailed evaluation of airflow velocity distribution and its deceleration behind the vehicle at different driving speeds: 13,88 m/s, 19,44 m/s, 25,00 m/s, and 36,11 m/s.

The numerical simulation results showed that transporting bicycles increases aerodynamic drag in all cases; however, the magnitude of this effect significantly depends on the vehicle body type and the bicycle mounting method. The smallest negative impact on airflow was observed for the SUV with rear-mounted bicycles, while the greatest impact occurred when bicycles were mounted on the roof, particularly at higher driving speeds. The calculated theoretical fuel consumption demonstrated that, as driving speed increases, additional fuel consumption may reach up to one-fifth of the baseline fuel consumption. The results were compared with experimental data reported in the literature, and the agreement of observed trends confirms that the applied methodology is valid and reflects real operating conditions.