Abstract: A fairing apparatus for reducing aerodynamic drag of a tanker in a freestream, and including a fairing body with a roof section, and left and right side sections connected to and extending below the roof section. Fasteners, for example, mount the fairing body on a cab of the tanker so that the roof, left, and right side sections extend from the roof, left and right side surfaces, respectively, of the cab towards a cylindrical tank carried behind the cab to reduce the gap between the cab and the tank and impede cross-flow therethrough, and the fairing surfaces of the roof, left, and right side sections are angled and preferably curvilinearly contoured to redirect airflow from the top and side surfaces of the cab to the curvilinearly contoured top and side surfaces of the tank to compensate for a profile mismatch between the cab and the taller and/or wider tank.

Abstract: A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly, by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly. The fairing body has a tapered aerodynamic surface that extends from a front end to a rear end of the fairing body with a substantially U-shaped cross-section that tapers in both height and width. Fasteners or other mounting devices secure the fairing body to an underside surface of the vehicle body, so that the front end is immediately downstream of the vehicle wheel assembly and a bottom section of the tapered aerodynamic surface rises towards the underside surface as it extends in a downstream direction.

Abstract: An aerodynamic base drag reduction and stability control apparatus and method uses a plurality of articulable base flaps each hingedly connected near one of a left side edge, a right side edge, a top side edge, and a bottom side edge of a rear end base of a vehicle so that each of the base flaps have a corresponding range of motion between a first position subject to direct impingement by a free stream adjacent the vehicle in motion and a second position not subject to direct impingement by the free stream. And a controller independently actuates the base flaps to corresponding desired positions relative to the free stream and within the corresponding ranges of motion to produce a desired combined aerodynamic drag reducing and/or stabilizing effect on the vehicle in motion.

Abstract: A wheel fairing and preferably a set of wheel fairings for reducing aerodynamic drag caused by the left-side and right side wheel sets of a rear wheel assembly supporting a trailer body at its rear end. The fairing body includes a tapered aerodynamic surface with a substantially U-shaped cross-section that tapers from a second end to a first end, and a base surface at the second end with a substantially same dimensional profile as one of the left-side or right-side wheel sets. Fasteners or other mounting devices secure each fairing body to an underside of the trailer body either upstream (as a nose fairing) or downstream (as a tail fairing) of the rear wheel assembly so that the second end is adjacent to an exposed rolling surface of the left-side or right side wheel set.

Abstract: A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly, by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly. The fairing body has a tapered aerodynamic surface that extends from a front end to a rear end of the fairing body with a substantially U-shaped cross-section that tapers in both height and width. Fasteners or other mounting devices secure the fairing body to an underside surface of the vehicle body, so that the front end is immediately downstream of the vehicle wheel assembly and a bottom section of the tapered aerodynamic surface rises towards the underside surface as it extends in a downstream direction.

Abstract: An apparatus for reducing the aerodynamic drag of a bluff-bodied vehicle such as a tractor-trailer in a flowstream, the bluff-bodied vehicle of a type having a leading portion, a trailing portion connected to the leading portion, and a gap between the leading and trailing portions defining a recirculation zone. The apparatus is preferably a baffle assembly, such as a vertical panel, adapted to span a width of the gap between the leading and trailing portions so as to impede cross-flow through the gap, with the span of the baffle assembly automatically adjusting for variations in the gap width when the leading and trailing portions pivot relative to each other.

Abstract: An apparatus for reducing the aerodynamic drag of a wheeled vehicle in a flowstream, the vehicle having a vehicle body and a wheel assembly supporting the vehicle body. The apparatus includes a baffle assembly adapted to be positioned upstream of the wheel assembly for deflecting airflow away from the wheel assembly so as to reduce the incident pressure on the wheel assembly.

Abstract: An aerodynamic base drag reduction apparatus and method for bluff bodies, such as tractor-trailer trucks, utilizing a pair of lift surfaces extending to lift surface tips and located alongside the bluff body such as on opposing left and right side surfaces. In a flowstream substantially parallel to the longitudinal centerline of the bluff body, the pair of lift surfaces generate a pair of counter-rotating trailing vortices which confluence together in the wake of the bluff body in a direction orthogonal to the flowstream. The confluence draws or otherwise turns the flowstream, such as the flowstream passing over a top surface of the bluff body, in and around behind a trailing end of the bluff body to raise the pressure on a base surface at the trailing end and thereby reduce the aerodynamic base drag.

Abstract: An apparatus for reducing the aerodynamic base drag of a bluff body having a leading end, a trailing end, a top surface, opposing left and right side surfaces, and a base surface at the trailing end substantially normal to a longitudinal centerline of the bluff body, with the base surface joined (1) to the left side surface at a left trailing edge, (2) to the right side surface at a right trailing edge, and (3) to the top surface at a top trailing edge. The apparatus includes left and right vertical boattail plates which are orthogonally attached to the base surface of the bluff body and inwardly offset from the left and right trailing edges, respectively. This produces left and right vertical channels which generate, in a flowstream substantially parallel to the longitudinal centerline, respective left and right vertically-aligned vortical structures, with the left and right vertical boattail plates each having a plate width defined by a rear edge of the plate spaced from the base surface.

Abstract: An apparatus for reducing the aerodynamic drag of a wheeled vehicle in a flowstream, the vehicle having a vehicle body and a wheel assembly supporting the vehicle body. The apparatus includes a baffle assembly adapted to be positioned upstream of the wheel assembly for deflecting airflow away from the wheel assembly so as to reduce the incident pressure on the wheel assembly.

Abstract: An apparatus for reducing the aerodynamic drag of a bluff-bodied vehicle such as a tractor-trailer in a flowstream, the bluff-bodied vehicle of a type having a leading portion, a trailing portion connected to the leading portion, and a gap between the leading and trailing portions defining a recirculation zone. The apparatus is preferably a baffle assembly, such as a vertical panel, adapted to span a width of the gap between the leading and trailing portions so as to impede cross-flow through the gap, with the span of the baffle assembly automatically adjusting for variations in the gap width when the leading and trailing portions pivot relative to each other.

Abstract: An aerodynamic base drag reduction apparatus and method for bluff bodies, such as tractor-trailer trucks, utilizing a pair of lift surfaces extending to lift surface tips and located alongside the bluff body such as on opposing left and right side surfaces. In a flowstream substantially parallel to the longitudinal centerline of the bluff body, the pair of lift surfaces generate a pair of counter-rotating trailing vortices which confluence together in the wake of the bluff body in a direction orthogonal to the flowstream. The confluence draws or otherwise turns the flowstream, such as the flowstream passing over a top surface of the bluff body, in and around behind a trailing end of the bluff body to raise the pressure on a base surface at the trailing end and thereby reduce the aerodynamic base drag.