When grooves were optimized, a drag reducing efficiency of more than 13% was achieved, which did not vary during the test lasting 1 h.
Results indicated that there were no obvious differences of the drag-reducing characteristics between conventional drag-reducing fluid and new drag-reducing nanofluid.
Drag-reducing additives are classified into three categories: polymers, fibers and surfactants.
Consequently, solubility of the drag-reducing additives in the heavy crude oil is a key requirement.
DRP = drag-reducing polymer; PEG = polyethylene glycol.
avDRP = DRP compound derived from Aloe vera; DRP = drag-reducing polymer.
David Albritton, a spokesman for General Motors' product development division, said in an email that the three main areas to focus on when trying to make vehicles more fuel efficient were reducing aerodynamic drag, reducing weight and improving mechanical efficiency.
Experimental methods and data treatment for evaluating efficiency of various drag reducing agents (DRA) for turbulent flows of crude oil are discussed.
Although Persian wheels and norias are mechanically quite efficient, the main source of loss from these types of device is that some water is spilled from the buckets and also there is a certain amount of friction drag caused when the buckets scoop up water, which again reduces efficiency.
However, opening the windows creates aerodynamic drag, disrupting the flow of air across the car, which can also reduce efficiency.
But ordinarily, higher frequencies also reduce efficiency.
