초록 ▼

An improved method and device for the reduction of aerodynamic drag and for improved performance of vehicles by increasing the pressure on the base of the trailing vehicle or vehicle component by controlling the boundary layer as it exists the vehicle trailing edge. The subject invention consists of

An improved method and device for the reduction of aerodynamic drag and for improved performance of vehicles by increasing the pressure on the base of the trailing vehicle or vehicle component by controlling the boundary layer as it exists the vehicle trailing edge. The subject invention consists of a multiple panels located near the base area of a bluff base vehicle. The flow control objectives are accomplished by positioning minimally sized panels comprising the invention in close proximity to the side and top surfaces of the vehicle, where the leading edge of each panel is positioned in close proximity to the trailing edge of the vehicle. The side panels comprising the invention are laterally positioned outboard of the side surface of the vehicle. The top panels are vertically positioned above the top surface of the vehicle.

대표청구항 ▼

1. An apparatus for reducing the aerodynamic drag of a body having a bluff base, a top, a front, a bottom, a first side, and a second side, the bluff base having a left half and a right half on either side of the centerline, the apparatus comprising: a first substantially rectangular side panel;a se

1. An apparatus for reducing the aerodynamic drag of a body having a bluff base, a top, a front, a bottom, a first side, and a second side, the bluff base having a left half and a right half on either side of the centerline, the apparatus comprising: a first substantially rectangular side panel;a second substantially rectangular side panel;a substantially rectangular top panel;each of the panels having a width, length, and thickness;wherein the first and second side panels are symmetrically positioned about the centerline of the bluff base in opposition and the top panel is positioned symmetrically about the bluff base centerline, wherein the first side panel is attached to the first side of the body, the second side panel is attached to the second side of the body and the top panel is attached to the top of the body so that the first side panel extends aft and is approximately parallel to the first side of the body, the second side panel extends aft and is approximately parallel to the second side of the body and the top panel extends aft and is approximately parallel to the top of the body and each panel is positioned longitudinally such that a leading edge of the panel is positioned forward of, and in close proximity to, a corresponding trailing edge of the body, wherein each of the first and second side panels is set outboard in close proximity to, and at substantially similar distances from, the respective side of the body a distance less than 25 percent of a width of the body, each of the first and second side panels being positioned to define a side gap between the side panel and the respective side of the body, wherein the top panel is set above the body top surface in close proximity to the top body surface a distance less than 25 percent of the body width, the top panel being positioned to define a top gap between the top panel and the top body surface;wherein the width of each of the first and second side panels is less than the body width, the thickness of each of the first and second side panels is less than 25 percent of the body width, and the length of each of the first and second side panels is substantially equivalent to the vertical height of the body bluff base;wherein the width of the top panel is less than the body width, the thickness of the top panel is less than 25 percent of the body width, and the length of the top panel is substantially equivalent to the width of the body bluff base;wherein each of the first and second side panels defines an outer surface facing in the same direction as the corresponding side of the body and an inward surface facing the opposing side panel, and each of the first and second side panels is configured, when exposed to a flow of air along the body, to separate the low energy and low velocity boundary layer air passing over the sides of the body from the high velocity external free-stream air; andwherein each of the first and second side panels is configured, when exposed to the flow of air along the body, to direct the low energy boundary layer air through the side gap between the side panel and the respective side of the body and into the region immediately downstream of the bluff base, enabling the high velocity free stream air to continue aft along the outer facing surface of each side panel where the air will exit the side panel trailing edge and expand into the base area region downstream of the low energy boundary layer air;wherein the top panel defines an outer surface facing in the same direction as the corresponding top of the body and an inward surface facing downward, and the top panel is configured, when exposed to the flow of air along the body, to separate the low energy and low velocity boundary layer air passing over the top of the body from the high velocity external free-stream air; andwherein the top panel is configured, when exposed to the flow of air along the body, to direct the low energy boundary layer air through the top gap between the top panel and the top body surface and into the region immediately downstream of the bluff base, enabling the high velocity free stream air to continue aft along the outer facing surface of the top panel where the air will exit the top panel trailing edge and expand into the base area region downstream of the low energy boundary layer air. 2. The apparatus of claim 1, wherein the right-side edge of the top panel is joined to the adjacent upper-side edge of the first side panel and the left-side edge of the top panel is joined to the adjacent upper-side edge of the second side panel to form a single inverted U shaped structure. 3. The apparatus of claim 1, wherein the lengthwise trailing edge of each panel is linear and parallel to the body bluff base. 4. The apparatus of claim 1, wherein the streamwise cross-sectional shape of each panel is of constant thickness. 5. The apparatus of claim 1, wherein the leading edge of each panel is aerodynamically sharp. 6. The apparatus of claim 1, wherein the trailing edge of each panel is aerodynamically sharp. 7. The apparatus of claim 1, wherein the streamwise cross-sectional shape of each panel is diamond shaped. 8. The apparatus of claim 1, wherein the streamwise cross-sectional shape of each panel is triangular shaped. 9. The apparatus of claim 1, wherein the streamwise cross-sectional shape of each panel is airfoil shaped. 10. The apparatus of claim 1, wherein the body is a vehicle having swinging rear doors on the left half and the right half of the bluff base, and further comprising control means connected between the vehicle and each panel for maintaining each panel in an operating position and for stowing each panel when not in use. 11. The apparatus of claim 1, wherein the body is a vehicle having a rollup rear door on the base, and further comprising control means connected between the vehicle and each panel for maintaining each panel in an operating position and for stowing each panel when not in use. 12. An apparatus in accordance with claim 10 wherein said control means comprises: a first slide system connecting the first side panel to the first side of the body,a second slide system connecting the second side panel to the second side of the body,a third slide system connecting the top panel to the top of said body. 13. An apparatus in accordance with claim 10 wherein said control means for maintaining each said panel in an operating position and to allow each said panel to move to a stowed position further comprising: a first powered slide system connecting the first side panel to the first side of the body,a second powered slide system connecting the second side panel to the second side of the body,a third powered slide system connecting the top panel to the top of said body,said control means to maintain each said panel in operating position includes a slide compression force and mechanical stop means for preventing forward movement of said first side panel from said operating position and preventing forward movement of said second side panel from said operating position and preventing forward movement of said top panel from said operating position,said control means includes means to allow said first side panel to slide from said operating position towards front of the vehicle and to allow said second side panel slide from said operating position towards front of the vehicle and to allow said top panel slide from said operating position towards front of the vehicle when said rear swinging doors are opened or when the trailing edges of said panels impact an object. 14. An apparatus in accordance with claim 11 wherein said control means comprises: a first slide system connecting the first side panel to the first side of the body,a second slide system connecting the second side panel to the second side of the body,a third slide system connecting the top panel to the top of said body. 15. An apparatus in accordance with claim 11 wherein said control means for maintaining each said panel in an operating position and to allow each said panel to move to a stowed position further comprising: a first powered slide system connecting first said panel to right half of said vehicle,a second powered slide system connecting second said panel to left half of said vehicle,a third powered slide system connecting third said panel to top of said vehicle,said control means to maintain each said panel in operating position includes a slide compression force and mechanical stop means for preventing forward movement of said right half panel from said operating position and preventing forward movement of said left half panel from said operating position and preventing forward movement of said top panel from said operating position,said control means includes means to allow said right half panel to slide from said operating position towards front of the vehicle and to allow said left half panel slide from said operating position towards front of the vehicle and to allow said top panel slide from said operating position towards front of the vehicle when said rear rollup door is opened or when the trailing edges of said panels impact an object.