Computational Characterization of Drag Reduction for Platooning Heavy Vehicles

Abstract

This thesis uses Computational Fluid Dynamics to analyze the aerodynamic properties of multiple heavy vehicle groups in leader-follower configurations, referred to as platoons. The primary metric of interest is the resistive aerodynamic force experienced in the freestream direction, commonly known as drag. The computational model first was validated using a simplified car body for both single and multiple body simulations. After validation, three platooning topics were examined: two vehicle platoons, three vehicle platoons, and multiple geometry two vehicle platoons. It was discovered that at close distances the follower vehicle interferes with the formation of the leader vehicle wake, offering significant drag reduction for both vehicles. At larger distances, it was found that the follower vehicle experiences near constant benefit until the end of the lead vehicle slipstream, at which point the drag rapidly transitions to the single vehicle value. Upon analysis of three vehicle platoons, it was observed that the interior vehicle drag could be reduced below that of the outer vehicles at small spacings and thus larger platoons can offer more benefit per vehicle than their smaller counterparts. Upon investigation of platoons with multiple geometries, it was discovered that placing the least aerodynamic vehicle in the follow position offers the most potential for overall platoon drag reduction.