Criteria for Choosing and Evaluating Aerodynamic Devices for Reducing Fuel Consumption of Trucks 750701
A general approach to the decision to use an aerodynamic device is outlined with the objective to increase profits within the framework of a corporate priority system. Many factors affect this economic decision. The process by which the decision is reached involves both a vehicle and an economic model. Three major considerations are: a) the aerodynamic performance of a proposed device, especially with significant cross winds, b) the structural characteristics of the device with regard to failure model, and the impact of the device of tractor or trailer body, and c) whether the device is tractor or trailer mounted.
It is noted that the attachment of a device is generally associated with a change in the equilibrium operating speed where the power required equals the power available. This change can significantly reduce the potential fuel savings to an impractical level, especially if the device has a poor cross wind behavior. The difficulty of conducting reliable fleet tests is discussed. Such tests can be very time-consuming while resulting in uncertain conclusions. It is recommended that a controlled test used combined with a realistic appraisal of changes to be expected in fleet operation.