Abstract: Aircraft fuel tank joints and related methods. The aircraft fuel tank joints comprise a first structural member comprising a first joint face, a second structural member comprising a second joint face that is spaced apart from the first joint face by a gap, a sealant dam compressed between the first and second joint faces and defining the gap, a first sealant zone on a first side of the sealant dam within the gap, and a second sealant zone on a second side of the sealant dam within the gap. The sealant dam and the first and second zones of sealant substantially fill, and form three independent seals within, the gap. The methods comprise substantially filling the gap with the sealant dam, the first zone of sealant, and the second zone of sealant, and compressing the sealant dam between the first and second faces to the compressed thickness.

Abstract: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy attenuating portion. The energy attenuating portion includes first and second edge sections separated by an adaptable section. The adaptable section may be rigid in a first range of directions and compressible in a second range of directions.

Abstract: An aircraft includes a fuselage airframe and a wing airframe that is subject to flight loads. The fuselage airframe includes fore/aft floor beams having a plurality of floor intercostals laterally extending therebetween and fore/aft roof beams with a plurality of roof intercostals laterally extending therebetween. Each of a plurality of cabin frames extends generally vertically between respective floor and roof beams. The wing airframe includes forward and aft wing spars with a plurality of wing ribs extending therebetween. At least one fuel tank, that is configured to contain a pressurized fuel such as pressurized hydrogen fuel, integrally forms at least a portion of one of the beams, the intercostals, the frames, the spars and/or the ribs such that the fuel tank is subject to the flight loads.

Abstract: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy attenuating portion. The energy attenuating portion includes first and second edge sections separated by an adaptable section. The adaptable section may be rigid in a first range of directions and compressible in a second range of directions.

Abstract: An enclosure structure, and an aerodynamic configuration adjuster arranged on an outer surface of same are provided. The aerodynamic configuration adjuster is of a grid structure capable of surrounding the enclosure structure, and the grid structure comprises a plurality of grid cells, at least some of grid cells have bevel edges, and the attack angle of a fluid is changed when the fluid passes over the bevel edges. The aerodynamic configuration adjuster changes the aerodynamic configuration of the fluid, and thus the resistance coefficient becomes smaller such that a pressure differential between the pressures at a incident flow surface and a back surface of the enclosure structure is reduced, thereby reducing a forward resistance; and in addition, due to a smaller resistance coefficient, the amplitude of a transverse vortex-induced resonance can also be reduced, thereby reducing vibration.

Abstract: An enclosure with a frequency mixing and absorbing device on an outer surface is provided. The frequency mixing and absorbing device includes a deformable body located on an outer surface of the enclosure, the deformable body includes a flexible body and/or an elastic body, the flexible body is a flexible hollow body or a flexible solid body, the elastic body is an elastic hollow body or an elastic solid body. When the direction of the incoming flow is from left to right, it acts on the deformable body at a windward side, that is, the change of pressure will be converted into the volume change of the deformable body. In this way, the fluctuating energy of the incoming flow can be absorbed and stored by the deformation of the deformable body, and the fluctuating energy is transferred to the volume change.

Abstract: An enclosure having an outer surface with a vortex-induced vibration suppression function is provided. The outer surface of the enclosure is provided with a plurality of annular recesses surrounding the enclosure, such that alternately concave and convex annular recesses and annular bosses configured for disrupting a boundary layer of a laminar flow are formed on the outer surface of the enclosure. An outer surface of the annular boss is provided with a plurality of air guiding grooves, and the plurality of air guiding grooves are distributed in a circumferential direction of the annular boss. The air guiding grooves are inclined upward or downward, such that part of an upwind incoming flow flowing to the annular boss can be guided into the annular recesses adjacent to the annular boss via the air guiding grooves. With the convex-concave outer surface, the cause of formation of the vortex-induced vibration can be prevented.

Abstract: The invention relates to an aerodynamic wind deflector for use with pitched panels or structures mounted on horizontal, flat surfaces. More particularly, the invention relates to a wind deflector, including a contoured surface, for deflecting aerodynamic forces away from a pitched structure, such as a solar panel, mounted to a horizontal, flat surface, such as a roof top, wherein the structure is subjected to such aerodynamic forces. The wind deflector may further include a customized fin or fins as part of the design.

Abstract: A protective shelter includes an enclosure having at least a floor, at least one sidewall coupled to the floor, a protected opening in the at least one sidewall, and a roof coupled to the at least one sidewall. The protective shelter includes a plurality of attachment fixtures each coupled to at least one of a set including the sidewall and the roof and a plurality of recesses at the at least one sidewall. Each of the plurality of recesses is sized to receive therein an anchoring assembly coupled to one of the plurality of attachment fixtures and couplable to a respective anchoring device on an underlying substrate.

Abstract: A loss prevention device, method and system for a structure subject to aerodynamic lift upon exposure to a wind event is disclosed having at least one tensioner coupled to the structure, at least one anchor attached to a fixed surface, and at least one barrier semipermeable to airflow connected between the at least one anchor and the at least one tensioner and exposed to said wind event. A fraction of a wind energy of said wind event is divided between the structure and the barrier, such that a lift force induced in the structure by the wind energy is at least partially counteracted by a strain induced in the barrier by the wind energy.

Abstract: A rooftop photovoltaic solar system is disclosed. The solar system comprises a plurality of photovoltaic modules forming a rooftop array, the rooftop array having at least one edge and a wind deflector positioned along the edge of the rooftop array, the wind deflector constrained in a first configuration by a fuse. In the first configuration the wind deflector comprises a deflecting portion adapted to deflect wind blowing on the rooftop above the rooftop array and a ventilation portion having a plurality of openings, the openings positioned to permit airflow under the rooftop array. The wind deflector assumes a second configuration upon release of the fuse. In the second configuration, the deflecting portion is elevated from the first configuration and the ventilation portion is positioned to permit less airflow through the plurality of openings than in the first configuration.

Abstract: A rooftop photovoltaic solar system is disclosed. The solar system comprises a plurality of photovoltaic modules forming a rooftop array, the rooftop array having at least one edge and a wind deflector positioned along the edge of the rooftop array, the wind deflector constrained in a first configuration by a fuse. In the first configuration the wind deflector comprises a deflecting portion adapted to deflect wind blowing on the rooftop above the rooftop array and a ventilation portion having a plurality of openings, the openings positioned to permit airflow under the rooftop array. The wind deflector assumes a second configuration upon release of the fuse. In the second configuration, the deflecting portion is elevated from the first configuration and the ventilation portion is positioned to permit less airflow through the plurality of openings than in the first configuration.

Abstract: Methods and structures for a composite truss structure are provided. The structure includes a web formed of a plurality of sheets of composite material, each sheet including a first face and an opposing second face and each face including a length and a width. Each of the plurality of sheets are coupled to at least one other of the plurality of sheets face to face such that the length and width of each face substantially match the length and width of a face of an adjacent sheet. The plurality of sheets are formed to include an upper chord member, a lower chord member, and a plurality of web members extending therebetween. The structure also includes at least a first flange plate coupled to the web proximate an outer periphery of the web.

Abstract: Disclosed is a roof spoiler that effectively disrupts the attached flow of wind upon a roof surface. This spoiler has a stowed position, whereby it is almost completely out of the view of passersby. It also has a deployed position, wherein a barrier is projected vertically, or substantially vertically, so as to disrupt the flow of air over the roof surface. This spoiler utilizes a hinged design to move between these two positions. The spoiler is specially designed to operate in conjunction with a gutter mounted along the leading edge of the roof. In the stowed position, a portion of the spoiler covers the open gutter. In one embodiment, the spoiler is L-shaped to facilitate its stability in the deployed position.

Abstract: A modular strake for reducing the effects of wind on utility structures is disclosed. The strake is comprised of individual fin sections that may easily be attached to a utility structure, preferably in a triple helix pattern. The modular strakes may be installed on a utility structure after is has been placed into service.

Abstract: A transportable apparatus for shelter comprising two sections, a base section and a top section. The base section and the top section have cavities that can be filled with water or are pre-filled with foam. The top section may be cone-shaped or dome-shaped, and is dimensioned to be placed on the base section. After the top section is placed on the base section, the top section can be secured to the base section via bolts. Finally, both the top section and bottom section are divided into sections such that if one section develops a leak the other sections remain unaffected.

Abstract: A turbulence-creating device is mounted to the roof, such that high winds flowing across the roof are caused to become turbulent, thereby interfering with the laminar flow and lift which would otherwise be created. The turbulence-creating devices comprise generally V-shaped or curved spoilers, many of which are pivotally mounted to a vertical mast attached to the roof such that the spoilers face in the direction of the oncoming wind and are shaped to disturb the laminar flow, thereby preventing lift from being generated. In some embodiments, fixed omnidirectional spoilers with curved sides are provided.

Abstract: A rooftop photovoltaic solar system is disclosed. The solar system comprises a plurality of photovoltaic modules forming a rooftop array, the rooftop array having at least one edge and a wind deflector positioned along the edge of the rooftop array, the wind deflector constrained in a first configuration by a fuse. In the first configuration the wind deflector comprises a deflecting portion adapted to deflect wind blowing on the rooftop above the rooftop array and a ventilation portion having a plurality of openings, the openings positioned to permit airflow under the rooftop array. The wind deflector assumes a second configuration upon release of the fuse. In the second configuration, the deflecting portion is elevated from the first configuration and the ventilation portion is positioned to permit less airflow through the plurality of openings than in the first configuration.

Abstract: Methods and structures for a composite truss structure are provided. The structure includes a web formed of a plurality of sheets of composite material, each sheet including a first face and an opposing second face and each face including a length and a width. Each of the plurality of sheets are coupled to at least one other of the plurality of sheets face to face such that the length and width of each face substantially match the length and width of a face of an adjacent sheet. The plurality of sheets are formed to include an upper chord member, a lower chord member, and a plurality of web members extending therebetween. The structure also includes at least a first flange plate coupled to the web proximate an outer periphery of the web.

Abstract: A low-cost hurricane and earthquake resistant house structure includes a rounded shape external wall constructed of a plurality of circumferentially adjacent wall segments, each secured to an adjacent structural vertical stud secured to the ground via a shock absorber. Each wall segment includes a plurality of blocks located and secured on top of one another. A foundation groove receives at least a portion of a lowest block of each wall segment therein, and spaced from inside foundation walls. An aerodynamic roof is secured to the vertical studs, and a floor is mounted on shock absorbers on the ground and connected to the wall with a flexible material.

Abstract: The invention relates to an aerodynamic wind deflector for use with pitched panels or structures mounted on horizontal, flat surfaces. More particularly, the invention relates to a wind deflector, including a contoured surface, for deflecting aerodynamic forces away from a pitched structure, such as a solar panel, mounted to a horizontal, flat surface, such as a roof top, wherein the structure is subjected to such aerodynamic forces. The wind deflector may further include a customized fin or fins as part of the design.

Abstract: A solar energy collection assembly includes a wind deflector and a solar module. A method of assembling includes roll forming frame sections of channel from sheet metal, connecting the frame sections to form an upright frame, and attaching the wind deflector and solar module to the frame.

Abstract: A shielding system that mitigates the effects of wind on an open-air venue by at least partially deflecting wind flow over the field. The shielding system includes shielding modules in abutment around the periphery of the field, each module including an upright member and a horizontal member. The upright member is curvilinear and projects inward toward the field, while the horizontal member is generally planar, mounted at the lower end of the upright member, and it also projects inward. The upright member and the horizontal member define a closed trap zone. An impinging airstream encounters the convex upwind side of the shielding system and is lifted over the field. At the downwind side of the shielding system, the airflow pressure against the closed trap zones produces a region of high pressure, deflecting the airflow over the downwind side of the shielding system.

Abstract: An apparatus attached to the roof perimeter to mitigate wind-generated vortices and uplift loads on the roof perimeter area of a building, applicable for both new constructions and retrofits of existing buildings. The apparatus comprises at least one face portion having face perforation and/or edge serration for increasing small-scale turbulence entrainment, equalizing pressure and disorganizing edge shear layer vorticity, and thus disrupting vortex formation. A roof edge vortex suppressor is preferably mounted along the entire circumference of a roof perimeter.

Abstract: An internal stiffening member of varying configurations in which the stiffening elements support the skin using a compression-only load path is disclosed. In the preferred embodiment, the stiffening element has a peripheral edge that is adapted to be press fit into contact with the skin. The stiffening member may be held in place by various retention devices. Another configuration is a slip-in rib having a flange with a peripheral channel in which a filler material is disposed. The rib is inserted into an assembled structural box beam, and the filler material is used to fill any gaps between the slip-in rib and the interior surface of the structural box beam. The filler material is preferably an expandable material, such as an expandable foam-type material. However, in situations where a slip-in rib forms a primary structural rib, the filler material is preferably a structural adhesive or liquid shim material.

Abstract: Disclosed is a roof spoiler that effectively disrupts the attached flow of wind on a roof surface. Preferably, the spoiler is specially designed for installation with a gutter mounted on the roof fascia or along the leading edge of the roof. This spoiler utilizes a hinged design to move between two operating positions. The first position is a stowed position, whereby the spoiler extends beyond the gutter and is designed to be nearly invisible to passersby. In the stowed position, a portion of the spoiler covers the outer edge of the gutter (if present). A second portion of the spoiler may extend outward from the gutter. The second position is a deployed position, wherein a barrier is projected vertically, or substantially vertically, so as to disrupt the flow of air over the roof surface. In one embodiment, the spoiler rests upon the roof covering when in the deployed position. In another embodiment, the spoiler rests near or against the gutter or holding bracket.

Abstract: A roof ridge vortex suppressor may include a base portion configured to be attached to a pitched roof having sloped, generally planar first and second surfaces intersecting with one another at a roof ridge. An upright member may extend from the base portion and may be configured to extend generally vertically upward and away from the roof ridge. The upright member may include a plurality of perforations. First and second segments may extend away from the upright portion. The first segment may be configured to extend generally horizontally in a first direction, and the second segment may be configured to extend generally horizontally in a second direction facing opposite the first direction.

Abstract: A vortex suppressing system is disclosed. The system is associated with a pitched roof having sloped, generally planar first and second surfaces intersecting with one another at a roof ridge. The system may include a fascia member attached to a perimeter of the roof. The fascia member may extend generally outwardly away from the perimeter of the roof, and may be generally curved to define a generally arch-shaped cross-sectional shape of an outer face of the fascia member. Additionally, the system may include an assembly, which may include first and second end portions attached to the first and second surfaces, respectively. In addition, the assembly may include a bridging portion extending over the roof ridge and from the first end portion to the second end portion. The bridging portion may have a generally curved outer surface, which may be substantially symmetrical about a plane generally parallel to the roof ridge.

Abstract: A wind mitigation system for attachment to a residential or commercial building to mitigate wind suction forces known to damage roof structures, and to harness wind energy to create electricity. The system may comprise one or more rotating cylinders which make use of the Magnus effect, a scientific phenomenon involving air flow over a rotating cylindrical object. Rotating Magnus cylinders are installed on the roof, preferably at or near the roof-wall junction of a building in order to provide the greatest suppression of perpendicular wind forces and resulting vortices. Wind flowing across the Magnus cylinders creates a downward force that is transferred to the roof by structural support brackets. The downward force counters the upward lifting forces generated by high winds so as to prevent uplifting of the roof structure. Electrical energy is generated from oscillations resulting from variations in wind speed.

Abstract: An apparatus disposed along and attached to a wall edge to mitigate wind-generated vortices and suction loads on the wall, suitable and convenient for both new constructions and retrofits of existing buildings. Preferred configurations are described and include such types as wall edge cap, wall edge windscreen and wall edge wind spoiler, each utilizing a distinctive primary aerodynamic mechanism, often with optional secondary mechanisms to enhance vortex-suppressing effects.

Abstract: An apparatus disposed along and attached to a wall edge to mitigate wind-generated vortices and suction loads on the wall, suitable and convenient for both new constructions and retrofits of existing buildings. Preferred configurations are described and include such types as wall edge cap, wall edge windscreen and wall edge wind spoiler, each utilizing a distinctive primary aerodynamic mechanism, often with optional secondary mechanisms to enhance vortex-suppressing effects.

Abstract: A wind spoiler including a vertical member mounted vertically along a roof of a structure to extend above the plane of the roof for creating turbulence in wind flowing over the roof.

Abstract: An apparatus attached to the roof perimeter to mitigate wind-generated vortices and uplift loads on the roof perimeter area of a building, applicable for both new constructions and retrofits of existing buildings. The apparatus comprises at least one face portion having face perforation and/or edge serration for increasing small-scale turbulence entrainment, equalizing pressure and disorganizing edge shear layer vorticity, and thus disrupting vortex formation. A roof edge vortex suppressor is preferably mounted along the entire circumference of a roof perimeter.

Abstract: An assembly attached to the roof perimeter to mitigate wind-generated vortices and uplift loads on the roof perimeter area of a building, applicable for both new constructions and retrofits of existing buildings. The assembly comprises an overhung screen portion preferably having face perforation and outer edge serration for equalizing pressure and disorganizing shear layer vorticity, and thus disrupting vortex formation. A roof edge windscreen is generally mounted onto an existing fascia or bargeboard. As an option appropriate for new constructions, it can also be mounted directly onto a framing member in place of fascia or bargeboard.

Abstract: Disclosed is a roof spoiler that effectively disrupts the attached flow of wind upon a roof surface. This spoiler has a stowed position, whereby it is almost completely out of the view of passersby. It also has a deployed position, wherein a barrier is projected vertically, or substantially vertically, so as to disrupt the flow of air over the roof surface. This spoiler utilizes a hinged design to move between these two positions. The spoiler is specially designed to operate in conjunction with a gutter mounted along the leading edge of the roof. In the stowed position, a portion of the spoiler covers the open gutter. In one embodiment, the spoiler is L-shaped to facilitate its stability in the deployed position.

Abstract: An aerodynamic system attached to the outer side of the roof perimeter edge to mitigate wind generated vortices and uplift loads on the roof perimeter area of a building, applicable for both new constructions and retrofits of existing buildings. A roof edge guard is generally installed alongside a roof edge, and mounted onto an existing fascia or bargeboard. As an option most appropriate for new constructions, it can also be mounted directly onto a roof frame member in place of fascias or bargeboard. The configuration modifies the cross-sectional shape of otherwise abrupt roof edges that tend to generate strong vortex during high winds.

Abstract: The present invention provides wind flow bodies for use with a structure for decreasing the carrier wing effect on the structure by the formation of turbulence or reducing the dynamic pressure by deflecting the wind flow. The invention further provides a method for securing the composition of a structure against the onslaught of heavy winds, whereby zones, which are suitable for the formation of a critical carrier wing effect during heavy wind flow are identified on the structure, and the position of a wind flow body for generating turbulence for dampening the carrier wing effect, is then determined. Further zones are identified which are suitable for the formation of the dynamic pressure, and the operating position of a wind flow body is then determined for deflecting the corresponding wind flow for reducing the dynamic pressure.

Abstract: A method and apparatus for producing a downward, wind-induced lift force on a structure including attaching one or more omni-directional mushroom-shaped airfoil assemblies to the top of the structure which create a downward lift force as they are subjected to wind flow.

Abstract: The different illustrative embodiments provide a method and apparatus for installing an edge seal. In one illustrative example, a pre-cured edge seal is placed on an edge of a composite structure with a sealant to form a placed pre-cured edge seal. The placed pre-cured edge seal is then cured on the composite structure. In another illustrative embodiment, an edge of a structure is prepared with solvent, and a brush coat of sealant is applied to the top and the edge of the structure. A fillet is applied to the base of the edge of the structure. A pre-cured edge seal is applied to the edge of the structure, and the edge is cured.

Abstract: A system and method is described generally for affecting atmospheric change. The system and method include providing a high altitude conduit or track. The system and method also include providing a first material through the conduit or via a payload delivery system. Further, the system and method include expelling the first material into the atmosphere at high altitude.

Abstract: A barrier disposed within a computer housing includes a frame adapted to be secured to the computer housing; and a plurality of elongated members attached to the frame. The plurality of elongated members are disposed across the frame such that the plurality of elongated members are attached to an inner surface of the frame. The barrier defines separate compartments within the computer housing and at least one fan is disposed in a compartment separated by the barrier from another compartment in which at least one electronic component is disposed. A method of manufacturing a barrier includes providing a frame; attaching a plurality of elongated members to the frame; disposing the frame within the housing such that the frame defines separate compartments within the housing; disposing at least one fan in a compartment separated by the barrier from another compartment; and disposing at least one electronic component in the another compartment.

Abstract: The invention relates to a tool for preventing the vortex effect, comprising three corrugated tubes which extend helically from the upper end (2) of the tower (3), such as to cover only the upper part thereof. The helix pitch defined by the corrugated tube (1) along the length of the tower (3) is fixed using cords (5) which are attached at each revolution of the tube. The corrugated tube (1) is lifted with a cathead (6) which is disposed on the structure that is used to anchor (4) the tool to the tower (3), the structure comprising three T-shaped sections which form an X having sectors (9) fixed to the ends thereof. In addition, four legs (14) are welded to the aforementioned sectors and the tubes are wound around said legs.

Abstract: A building with a roof having a wind deflection system. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

Abstract: An aerodynamic system attached to the outer side of the roof perimeter edge to mitigate wind generated vortices and uplift loads on the roof perimeter area of a building, applicable for both new constructions and retrofits of existing buildings. A roof edge guard is generally installed alongside a roof edge, and mounted onto an existing fascia or bargeboard. As an option most appropriate for new constructions, it can also be mounted directly onto a roof frame member in place of fascias or bargeboard. The configuration modifies the cross-sectional shape of otherwise abrupt roof edges that tend to generate strong vortex during high winds.

Abstract: A method of making a shim comprises the steps of providing a first structural component, such as a rib foot of an aircraft wing. The rib foot is then scanned or mapped to generate the surface profile of the rib foot. The shim is then formed to include a feature on its surface which complements the surface profile of the assembly surface.

Abstract: An aerodynamic system attached to the outer side of the roof perimeter edge to mitigate wind generated vortices and uplift loads on the roof perimeter area of a building, applicable for both new constructions and retrofits of existing buildings. A roof edge guard is generally installed alongside a roof edge, and mounted onto an existing fascia or bargeboard. As an option most appropriate for new constructions, it can also be mounted directly onto a roof frame member in place of fascias or bargeboard. The configuration modifies the cross-sectional shape of otherwise abrupt roof edges that tend to generate strong vortex during high winds.

Abstract: The invention relates to a tool for preventing the vortex effect, comprising three corrugated tubes which extend helically from the upper end (2) of the tower (3), such as to cover only the upper part thereof. The helix pitch defined by the corrugated tube (1) along the length of the tower (3) is fixed using cords (5) which are attached at each revolution of the tube. The corrugated tube (1) is lifted with a cathead (6) which is disposed on the structure that is used to anchor (4) the tool to the tower (3), said structure comprising three T-shaped sections which form an X having sectors (9) fixed to the ends thereof. In addition, four legs (14) are welded to the aforementioned sectors and the tubes are wound around said legs.

Abstract: An architecture comprising an openwork of discrete, aerodynamic living units.

Abstract: A roof edge fascia or coping cover having an aerodynamic exterior shape mainly comprising a lower face portion, an intermediate face portion, and a top face portion. The lower face portion is either generally vertical, or sloping or curving upwardly and outwardly, forming an angle within 60° to the vertical outer wall surface of a building. The top face portion, of a substantial lateral size, is generally disposed within ±25° from horizontal. The intermediate face portion, having at least one segment of a substantial lateral size sloping or curving upwardly and inwardly, connects the lower and top face portions. Slope changes at a junction between any two adjacent face portions, or adjacent segments thereof, are generally less than or equal to 50°.

Abstract: An apparatus secured to extend upwardly from a rooftop for redirecting free oncoming flow of a gas passing over an edge of the rooftop. The apparatus has an elongated member having at least a lower flow-surface, and a leading edge portion having a leading-rim extending therealong. A plurality of supports is spaced along the elongated member. An upper-end of each support is secured to, integrated-with, or otherwise extends from the lower flow-surface of the elongated member. There may be several such elongated members that may be joined. The lower-end of each support extends from the rooftop or sidewall structure to provide a spaced relationship between the lower flow-surface and the rooftop. The leading-rim of the leading edge portion extends into the oncoming flow to redirect of at least a portion thereof so that it flows under the leading edge portion and along the lower flow-surface and, preferably, on into a re-circulation region above the rooftop.