Comparison of aerodynamic drag and underhood thermal analysis of two heavy-duty vehicles

Abstract

External aerodynamics and underhood thermal analyses of two heavy-duty vehicles, (1) cab-over engine (European style flat-front) and (2) conventional truck (North American class-8-style front engine), are being studied to assess their aerodynamic and underhood cooling performances. Both vehicles have similar geometrical dimensions, i.e. width, height and length. Three-dimensional computational fluid dynamics modelling and simulations are performed using StarCCM+® commercial software. Aerodynamic drag analysis is carried out separately for each configuration. Significant fuel savings are observed in a conventional truck when compared to cab-over engine configurations at all yaw angles. The major reduction in fuel consumption is observed mainly from the cabin designs alone (up to 7.5%). Apart from the aerodynamic drag analysis, underhood thermal analysis is also performed to compare both heavy-duty vehicle configurations. Based on the coolant temperatures, 12 and 10% thermal efficiency improvements are observed in conventional trucks when compared to cab-over engine for charge air cooler and radiator, respectively.