Aerodynamic apparatuses for trailer

There is described a top fairing for a trailer adapted to decrease drag and manage water. The top fairing comprises a surface for guiding air thereover, comprising a leading flange; a leading surface having a leading radius, the leading surface being joined to the leading flange and extending in a rearward direction; and a tailing surface having a tailing radius, the tailing surface in continuity to the leading surface in the rearward direction. The top fairing comprises openings disposed in the leading flange for managing water through the leading flange.

BACKGROUND

The subject matter of the present invention relates to an end of trailer fairing that improves aerodynamic performance of the trailer. More particularly, the present application involves fairing that features a specific geometric shape that includes a leading curved portion and a trailing curved portion that meets at a point of tangency. Improvements for water management are also part of the present application.

(b) Related Prior Art

Trailers towed by trucks and similar apparatuses for transporting cargo can be large, unwieldy, and include geometries which invite inefficiencies during travel. One aspect of these inefficiencies concerns the aerodynamics of the trailer. In an effort to improve trailer aerodynamics, trailers have been built, supplemented, or retrofitted with trailer skirts (or side skirts), devices affixed to the underside which limit air circulating in the empty space between the trailer's axles. By reducing the amount of airflow in this space, drag caused by turbulence is reduced and permits the trailer to be towed more efficiently, increasing the gas mileage and performance of the vehicle and its cargo. Other ways of improving aerodynamic performance of the trailer involves the provision of fairings to the end of the trailer. The fairings modify the airflow around or off of the end of the trailer to reduce drag. It is known to produce fairings that have a curved outer surface that extend from the leading edge of the fairing to the tailing edge of the fairing. These curved fairings change the airflow about the end of the trailer to reduce dragging force. Although capable of reducing some dragging force at the end of the trailer, additional fairing designs that can stabilize the airflow wake structure behind the trailer are desirable. As such, there remains room for variation and improvement within the art.

Furthermore, the existing top fairings present problems in relation with rain management. The shape of the existing top fairings prevents water to travel along the top surface of the trailers, to reach the rain gutters located at the rear edge of the top surface of the trailers for the rain to be drained without being projected to following vehicles. Therefore, nowadays, owners must select between in improvement to the drag of the trailer trough a top fairing or having a rain gutter for managing water on top of the trailer. There is therefore need for improvement with that respect.

Furthermore, with the presence of trailers having corrugations on the side, there is a need for an improvement in the side fairings being able to better marry the side surface and guide air along the side surface of the trailer toward the rear of the trailer, and that without a portion of the air getting under the side fairings, or having complicated solution in term of installation or of construction of the side fairings.

SUMMARY

In some aspects, the techniques described herein relate to a top fairing for a trailer, or a box truck (cube) including a boxed cargo space without departing from the scope of the present application, including: a surface for guiding air thereover, including a flange; a leading surface having a leading radius, the leading surface being joined to the flange and extending in a rearward direction; and a tailing surface having a tailing radius, the tailing surface in continuity to the leading surface in the rearward direction; and openings disposed in the flange for managing water through the flange.

In some aspects, the techniques described herein relate to a top fairing, wherein the flange and the leading surface are joining each other with a root angle of between 8 degrees and 22 degrees, more precisely about 20.7 degrees.

In some aspects, the techniques described herein relate to a top fairing, wherein the flange is a serrated flange.

In some aspects, the techniques described herein relate to a top fairing, wherein the flange has a depth perpendicular to its longitudinal orientation, and wherein the openings have funnel-shape walls extending through full depth of the flange.

In some aspects, the techniques described herein relate to a top fairing, wherein the openings extend into the leading surface.

In some aspects, the techniques described herein relate to a top fairing, wherein flange has a thickness, and the openings have a height greater than the flange.

In some aspects, the techniques described herein relate to a top fairing, wherein the tailing surface includes a cantilever portion.

In some aspects, the techniques described herein relate to a top fairing, including a support structure, and wherein the cantilever portion is rearward from the support structure.

In some aspects, the techniques described herein relate to a top fairing, wherein the top fairing includes a bridge portion frontward from the cantilever portion, wherein the bridge portion has clearance under while providing support to the tailing surface.

In some aspects, the techniques described herein relate to a top fairing, further includes side walls including a bar opening and a slot, a bar extending through the side walls, and a pair of brackets to be mounted to a top surface of the trailer, each one of the brackets being adapted to be secured to an extremity of the bar and including a wing interfacing with the slot distant from the bar to secure the top fairing against rotation.

In some aspects, the techniques described herein relate to a top fairing, wherein the brackets are adapted to be secured to corner members of the trailer.

In some aspects, the techniques described herein relate to a top fairing, wherein the bar has a transversal coordinate according to its axis, wherein the top fairing has a chord length measured from a leading edge of the leading surface to a tailing edge of the tailing surface, wherein the leading surface and the tailing surface join with each other at a meeting location, and wherein transversal coordinates of the meeting location and of the bar are within 10% of the chord length from each other.

In some aspects, the techniques described herein relate to a top fairing, wherein the top fairing has a chord measured from a leading edge of the leading surface to a tailing edge of the tailing surface, wherein the leading surface and the tailing surface join with each other at a meeting location, and wherein transversal coordinates of center of curvature of the leading radius, of center of curvature of the tailing radius and of meeting location are within 20% of the chord length from each other.

In some aspects, the techniques described herein relate to trailer with fairing including a fairing adapted to manage water.

In some aspects, the techniques described herein relate to a trailer with fairing, wherein the fairing includes side fairing mounted to side surfaces of the trailer.

In some aspects, the techniques described herein relate to a trailer with fairing, wherein the side surfaces include corrugations, and wherein each one of the side fairings includes a side-fairing flange, a side-fairing leading surface, and notches extending into the side-fairing flange and the side fairing leading surface, wherein the notches provide clearance for the corrugations to fill when the flange abuts the side surface of the trailer.

In some aspects, the techniques described herein relate to a fairing kit for decreasing drag, and a pair of top-fairing brackets adapted to mount the top fairing to a top surface of the trailer.

In some aspects, the techniques described herein relate to a fairing kit, further including side fairings and side-fairing brackets adapted to mount the side fairings to side surfaces of the trailer.

In some aspects, the techniques described herein relate to a fairing kit, wherein the side fairing brackets include a surface-contacting portion adapted to abut the side surfaces, and a fairing-mounting portion adapted for the side fairings to be mounted thereto, wherein the fairing mounting portion is adapted to be distant from the side surfaces.

In some aspects, the techniques described herein relate to a top fairing for a trailer including: a surface for guiding air thereover, including a flange; a leading surface having a leading radius, the leading surface being joined to the flange and extending in a rearward direction with a root angle between the flange and the leading surface of between 8 degrees and 22 degrees, more precisely about 20.7 degrees; and a tailing surface having a tailing radius, the tailing surface in continuity to the leading surface in the rearward direction, wherein the top fairing includes essentially the flange, the leading surface and the tailing surface in continuity to each according to essentially two radii for guiding air thereover.

DETAILED DESCRIPTION

The realizations will now be described more fully hereinafter with reference to the accompanying figures, in which realizations are illustrated. The foregoing may, however, be embodied in many different forms and should not be construed as limited to the illustrated realizations set forth herein.

With respect to the present description, references to items in the singular should be understood to include items in the plural, and vice versa, unless explicitly stated otherwise or clear from the text. Grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, and the like, unless otherwise stated or clear from the context. Thus, the term “or” should generally be understood to mean “and/or” and so forth.

The terms “top”, “up”, “upper”, “bottom”, “lower”, “down”, “vertical”, “horizontal”, “interior” and “exterior” and the like are intended to be construed in their normal meaning in relation with normal installation of the product, with normal orientation of the components being depicted onFIG.1.

Referring toFIGS.1to3, the present invention provides for a fairing110a back of the trailer112that improves aerodynamic performance of the trailer112to reduce drag on the trailer112when a truck (not depicted, located at the front of the trailer) is hauling the trailer112. The fairing110comprises a top fairing168that is attached to the top surface136of the trailer112, or the fairing110may be a side fairing170attached to the side surface134of the trailer112. Typically, the trailer112is provided with side fairings170on both of its side surfaces134, and with a top fairing168on its top surface136. The fairing110features a leading airflow surface114that has a leading radius. The leading airflow surface114meets a tailing airflow surface120at a meeting location122(seeFIG.10), and a common tangent line124(seeFIG.10) extends through the meeting location122and is tangent to both the leading airflow surface114and the tailing airflow surface120at this point. The fairing110is designed for the air to travel over the leading airflow surface114and to follow the tailing airflow surface120to result in an optimal reduction of drag on resulting from air led to the rear of the trailer112during transport.

FIGS.1to3illustrate a trailer112adapted to be hauled by a truck that features at its rear portion fairings110in accordance with an exemplary embodiment. The combination of the truck and trailer112extends in a longitudinal direction144which is the general direction of travel as the truck hauls the trailer112forward. The fairings110are designed to deflect airflow in an optimal manner around the back of the trailer112so that drag on the trailer112during travel is optimally reduced. The geometric design of the fairing110includes features that result in this optimal reduction of drag. Although three fairings110are shown at the back end of the trailer112, it is to be understood that the trailer112may be outfitted with only one or with two of the fairings110in other exemplary embodiments. The fairings110are preferably located proximate to the terminal end174of the trailer112, secured to the trailer112, and are forward of the terminal end174in the longitudinal direction144. In some instances, the fairings110may extend rearward of the terminal end174in the longitudinal direction144. The fairings110are located near the terminal end174of the trailer112because they are designed to affect the flow of air at the back end of the trailer112and behind the trailer112during travel. Additional fairings (not shown), not specifically discussed herein, can be employed e.g., at the bottom of the trailer112or in other locations on the trailer112as desired for combined effect on drag of the trailer112.

Top Fairing

With additional reference toFIGS.4to10, the top fairing168is located at the back end of the trailer112so that it is closer to the back terminal end174of the trailer112than to the front terminal end of the trailer112. The top fairing168may be spaced some amount forward of the back terminal end174in the longitudinal direction144, may terminate right at the back terminal end174, or may extend slightly rearward from the back terminal end174in the longitudinal direction144. The top fairing168extends almost all the way across the top surface136in the lateral direction146of the trailer112so as to extend about both the right and left side surfaces134. It is contemplated by the present application that the top fairing168covers the entire width of the trailer's box, which can reach about between 96″ to 100″, for instance.

FIG.7is a side view of the back end of the trailer112with the top fairing168positioned onto the top surface136of the trailer112. The top fairing168has a leading airflow surface114that is forward of a tailing airflow surface120in the longitudinal direction144. The top fairing168is typically made of an unibody component mounted to the top surface136secured with fixing components to the top surface136. The leading airflow surface114and the tailing airflow surface120may be constant or may vary along the width of the top fairing168. In other words, the leading airflow surface114and the tailing airflow surface120may be measured according to longitudinal planes (e.g., plane135,FIG.6) characterized by their transversal coordinate relative to a reference, e.g., the side edge of the trailer112. The leading airflow surface114and the tailing airflow surface120may be constant or vary as they are measured at different transversal coordinates. As such, it is to be understood, as used herein, that the leading airflow surface114and the tailing airflow surface120discussed herein may be measured according to any transversal coordinate over the width of the top fairing168. It is further to be understood that as used herein, when discussing the orientation of the surfaces114,120with respect to angles, radii, locations, ranges, etc. the portion of the surfaces114,120that are being measured or discussed are the outer surfaces of the leading airflow surface114and the tailing airflow surface120and not interior portions, if any, of these surfaces114,120. The surfaces114,120can be made of plastic and may be manufactured according to a first embodiment through a thermal plastic forming process, or according to another embodiment made of extruded plastic, the latter being characterized in constant characteristics of the surfaces114,120over the width of the top fairing168.

The leading airflow surface114has a leading edge160that is the forward most portion of the leading airflow surface114in the longitudinal direction144. Forward of the leading edge160is an anchoring flange142. The leading airflow surface114is oriented, from the anchoring flange142parallel to the top surface136, with a root angle116that is typically from 8 to 22 degrees, and more preferably from 12 to 22 degrees, and preferably about 20.7 degrees. The root angle116is oriented rearward in the longitudinal direction144. The root angle116is measured relative to the top surface of the anchoring flange142, itself parallel to the side surface134. In this regard, an angle of zero (0) degree refer to a surface parallel to the top surface136, and a root angle116that is of one-hundred and eighty (180) degrees refers to a leading airflow surface114that would be normal to the top surface136at the leading edge160. The leading airflow surface114is curved at a set amount so that the entire leading airflow surface114has a single leading radius127. The leading radius127is in the range from 500 millimeters to 900 millimeters. In more preferred embodiments, the leading radius127is from 700 millimeters to 800 millimeters, and preferably about 760 millimeters.

The profile includes a front radius, then a radius toward the rear and the last portion, of generally a few inches, is supposed to be flat in some embodiments. The same configuration can be used for the side fairing. The side fairing could include a rear flat portion of about 48 mm, the top fairing can include a rear flat portion of between 0 and 117 mm, depending of the gutter. The leading airflow surface114ends at a meeting location122where it meets the tailing airflow surface120. The tailing airflow surface120is a curved surface that extends from the meeting location122to a tailing edge121. The tailing edge121is about or rearward to the terminal end174in the longitudinal direction144. In the embodiment shown, the tailing airflow surface120is curved at a set amount so that the entire tailing airflow surface120has a single tailing radius128. The tailing radius128is in the range from 500 millimeters to 1800 millimeters. In more preferred embodiments, the tailing radius128is from 800 millimeters to 1600 millimeters, and preferably about 930 millimeters.

The leading airflow surface114and the tailing airflow surface120are oriented with respect to one another so that they share a common tangent line124that is about the apex (i.e., within the top 5% of the height of the top fairing168, and preferably within the 2.5% of its height) and about the center (i.e. within the range of 30% to 70% of the chord145measured from the leading edge160to the tailing edge121, and preferably within the 40% to 60% of the chord145). The meeting location122is the point of engagement between the leading airflow surface114and the tailing airflow surface120and in so far as the common tangent line124is common to both of these surfaces114,120. This arrangement affords airflow off of the leading airflow surface114to channel against the tailing airflow surface120with no disruption. The orientation and leading radius127of the leading airflow surface114and of the tailing airflow surface120results in a geometry of the top fairing168that causes an air flow to travel downward over the top fairing168around the rear of the trailer112to reduce dragging force while the truck is hauling the trailer112to improve its fuel efficiency.

The leading air flow surface114is spaced from the top surface136so that a gap152is present and the portion of the top fairing168that is below the leading air flow surface114is not in engagement with the top surface136.

The anchoring flange142is attached, typically glued with double-face automotive tape, to the top surface136. According to an embodiment, the anchoring flange142is glued over the width of the anchoring flange142(from about one side edge to about the other side edge of the top surface136) with sections of double-sided tape spaced with sections free of tape; the latter providing a gap of the thickness of the double-sided tape for water to flow toward a rain gutter at the rear end of the top surface136of the trailer112.

The installation of the top fairing168involves a bar126that extends between the top surface136and the surfaces114,120, and that extends sideways between the side wall132of the top fairing168to be secured to a mounting bracket178at both ends. The bar126can extend over the whole width of the top fairing168, and can be secured to the top fairing168at locations to reinforce the top fairing against deformation and/or vibration. The bar126can be a separate component from the top fairing168, or may be permanently assembled to the surfaces114,120.

It is to be understood that the bar126can be a component that is separate from the leading airflow surface114and the tailing airflow surface120, The bar126may be alternatively integral to the top fairing168. The bar126may be a single bar. The bar126may alternatively be made of a plurality of bar sections, either or not joined to each other. The bar126may be made of the same material than the portion of the top fairing168defining the leading airflow surface114and the tailing airflow surface120. The bar126may alternatively be made or of a different material than the surfaces114,120. Typically, the bar126presents more rigidity than the surface114,120.

The bar126is shown attached to the top surface136through the brackets178secured to the top of the trailer112on opposite sides in the lateral direction146(depicted onFIG.6), and more precisely close enough to the side edges of the trailer112to have the bolts securing the brackets178to the trailer112not penetrating in the interior compartment of the trailer112. The bar126extends through the openings133of side walls132(opening133depicted onFIG.10and identified onFIG.5with bar126extending therethrough) and is secured to brackets178, and an interface between an extending wing176and a slot172present in the side walls132exerts the anchoring flange142downward. A top wing166of the brackets178, presenting itself as an inward folding of a top portion of the brackets178, complete the interface of the top fairing168with the brackets178. The top wings166participate in preventing rotation of the top fairing168. The described mounting of the top fairing168provides some side clearance for transversal adjustment of the top fairing168. Accordingly, a single bar126provides the required strength to attach the top fairing168to the top surface136.

As discussed, the use of the bar126allows the side walls132, and consequently the leading airflow surface114and the tailing airflow surface120, to be secured to the trailer112without having to drill holes through the top surface136, which could result in rain or contaminants entering the compartment of the trailer112. In this manner, the compartment of the trailer112is made more secure by the use of the side-mounted brackets178and the bar126to retain the top fairing168to the trailer112. Although described as utilizing a single tubular bar126to secure the top fairing168, which provides advantages over alternatives, more than one bar or a bar of another shape may be used in other embodiments.

According to realizations, the tailing air flow surface120is adapted for a cantilevered portion to cover a rain gutter located at the rear end of the top surface136. The tailing airflow surface120may be adjusted to adapt rain gutters of different dimensions.

The side walls132have a rear edge138distant from the tailing edge121. The rear edge138defines a clearance under a cantilevered portion of the tailing surface120allowing the top fairing168to adapt to top surfaces having no rain gutter and rain gutters118of different dimensions, whereby mounting the brackets178, thus the top fairing168, farther (for a top surface136featuring no rain gutter) or closer (for a top surface136featuring a rain gutter118of up to e.g., 1⅜ of an inch to have the tailing edge121above the rain gutter118and reaching the terminal end174.

According to an embodiment, the rear edge138features an upward-rearward slop followed in the direction of the tailing edge121by a rearward portion. This shape is adapted to improve clearance while limiting the cantilevered portion of the tailing airflow surface120to an acceptable value.

According to a preferred realization, the tailing airflow surface120may be marked with indications (not depicted) where to cut the tailing airflow surface120based on the dimension of the rain gutter118to adapt to.

According to a preferred realization, the meeting location122, where uplift forces are at their maximum, is within 10% of the total chord145from the leading edge160to the tailing edge121relative to the position in the longitudinal direction of the center of the bar126. More preferably, it is within 5% relative to the position in the longitudinal direction of the center of the bar126.

The profile of the top fairing168may be defined by the parameters of the leading airflow surface114and the tailing airflow surface120, including the root angle, characteristics of their meeting, etc. According to a preferred realization, the root angle116is between 8 and 16 degrees, and more preferably between 12 and 16 degrees, and preferably about 14.4 degrees, more preferably about 13.4 degrees. The leading radius127is in the range from 500 millimeters to 1800 millimeters. In more preferred embodiments, the leading radius127is from 500 to 900 millimeters, and preferably from 700 millimeters to 800 millimeters, and preferably about 760 millimeters. The tailing radius128is in the same ranges than the leading radius, and preferably about 900 millimeters. The center of curvature of the leading radius127is located under the surfaces114,120and its longitudinal coordinate is within 20% of the chord145relative to the meeting location122, and preferably within 10% of the chord145relative to the longitudinal coordinate of the meeting location122. The center of curvature of the tailing radius128is located under the surfaces114,120and its longitudinal coordinate is within 20% of the chord145relative to the meeting location122, and preferably within 10% of the chord145relative to the longitudinal coordinate of the meeting location122. The side fairing tailing angle129(seeFIG.10for depiction of the top fairing168andFIG.12for depiction on the side fairing170) is between 10 and 30 degrees, and preferably more than 10 degrees, and more preferably more than 12 degrees. The angle of about 11.5 degrees is preferable in some embodiments of the side fairing.

According to another perspective, the ratio of the leading radius127over the tailing radius128is between 2 over 1 and 1 over 2, preferably between 3 over 2 and 2 over 3, preferably between 4 over 5 and 5 over 4, and preferably about 5 over 6.

Referring now toFIGS.15to21, according to embodiments, top fairings168feature an improved water management feature comprising a series of water inlets194having a generally funnel-shaped aperture196on the anchoring flange142extending over the whole depth of the anchoring flange142and ending with a e.g., curved opening198at the root of the leading airflow surface114, wherein the opening198has small height200and a inlet width204providing passage for big water drops to travel from in front of the anchoring flange142to under the top fairing168and finally reaching e.g., a rain gutter. Accordingly, water falling over the top surface136, instead of accumulating in front of the anchoring flange142, and travelling over the top fairing168and risking falling from the tailing edge121at the rear of the trailer112on following vehicles, are drained through the rain gutter118(see for exampleFIG.7).

Embodiments includes top fairings168featuring from 3 water inlets194(FIG.21) including two partial water inlets on the sides and a central one, and to more than 30 water inlets194. According to embodiments, the height200of the aperture196may vary from about the thickness of the anchoring flange142to up to three times the thickness of the anchoring flange142with low influence on drag reduction resulting from the use of the top fairing168. The present disclosure contemplates different shapes (e.g., straight, curved) and width202of side walls195for the funnel-shaped apertures196and spacing between the side walls195of neighbor water inlets194being null to a ratio of e.g., four time the width202. The present disclosure further contemplates general shapes of the opening198from being either straight or having a curved shape, or another shape appropriate in relation with the material in which the top fairing168is made of.

Side Fairing

Referring now toFIGS.1to3and11to14, the side fairing170extends in a vertical direction148of the trailer112along some, but typically not all, of the vertical height of the trailer112. The side fairing170is typically located closer to the top surface136of the trailer112than a bottom surface of the trailer112. The side fairing170may be located at the top surface136, or it may be spaced some distance from the top surface136in the vertical direction148. The side fairing170is mounted to the side surface134of the trailer112.

According to an embodiment, the side fairing170, which function is to direct the flow of air around the side of the trailer112and to an area behind the trailer112to result in less drag on the trailer112when the trailer112is hauled by a truck, has an anchoring flange142attached to the side surface134, and a leading airflow surface114that joins the anchoring flange142farther in the longitudinal direction144, and a tailing airflow surface120that follows the leading airflow surface114in the longitudinal direction144. The leading angle of the side fairing is about 11.5 degrees in some embodiments. The trailing edge of the side fairing is about 14.5 degree in some embodiments.

In some instances, the side surface134of the trailer112can include corrugations156that extend in horizontally in the longitudinal direction144. The side fairing170may be provided with notches154having an ogive-like shape having a pair of parallel edges157at the anchoring flange142leading to a curved apex158distant to the anchoring flange142. The notches154are adapted for the corrugations156to be disposed therein in order to allow the anchoring flange142of the side fairing170to marry the flat portion of the side surface134between the corrugations156.

The side fairing170has a leading airflow surface114and a120that have similar characteristics than the ones of the top fairing168.

According to an embodiment, the radii127,128of the side fairing170are respectively of about 1450 millimeters (or 1449 mm) and of about 900 millimeters (or 923 mm).

According to an embodiment, the side fairing170is secured to the side surface134using a series of mounting brackets188having surface-contacting portions190and fairing-mounting portions192spaced from the side surface134such as adapted to provide clearance for corrugations156and mounting screw tips. The mounting brackets188are adapted for the surface-contacting portions190to be secured to the side surface134with tape and/or rivets. The side fairing170is secured to the fairing-mounting portions192with screws.

According to a preferred embodiment, the side fairing170features recesses164for the head of the screw to not extend, or extend only slightly, over its outer surface114or120.

According to embodiment, the side fairings170may be mounted to extend beyond the terminal end174of the trailer112. In some embodiments, hinge notches184(of similar shape to the corrugation notches154) are present to provide clearance for hinges when opening the doors of the trailer112without the hinges flexing the side fairings170.

In is to be noted that the design of the top fairing168and the side fairing170may differ in that their root angle and their radii. However, it is preferred that profiles for the top fairing168and the side fairing170remain with the ranges listed herein.