The CargoCap system is the fifth transportation different from the previous conventional systems. This article concentrates on the aerodynamic drag of group travel Caps in CargoCap system because reducing the aerodynamic resistance of Caps is of paramount importance for building an economical and energy-saving CargoCap system. None of previous studies on aerodynamic drag have focused on this specific aspect since it is an innovative concept coming up with in recent years.

In this paper, a systematic analysis of the aerodynamic drag of group travel Caps in CargoCap system is presented with a strong validation of Computational Fluid Dynamics (CFD) method and convictive results of numerical simulation. Five groups including different number of Caps from 1 to 5 with distance between each two of 2 meters was simulated by the student version ANSYS Fluent 2020 R1. With the 3D RANS equations, standard k-ε model and standard wall function, a total of 5 CFD simulations were performed. The uppermost conclusion drawn is that the aerodynamic drag of every Cap is closely related to the position that it occupies in the group and the medial drag of the whole group showed a clear downward trend as the number of Caps increases. The average drag of the whole group can be considered as a measure of “travelling economy”. Increasing the number of Caps in one group moderately probably is an economical choice to form the group travel Caps while increasing excessively may not benefit a lot from the perspective of “travelling economy”.

This study presents a cogent research of the aerodynamic drag in single group where the amount of Caps is regularly varied, in CargoCap system. In addition, it provides a basic framework and tries to analyze aerodynamic drag of group travel Caps in CargoCap system from an innovative starting point.