Patent Publication Number: US-2023159113-A1

Title: Aerodynamic apparatuses for trailer

Description:
BACKGROUND 
     (a) Field 
     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&#39;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. 
     Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims. Accordingly, the drawings and the description are to be regarded as illustrative in nature and not as restrictive and the full scope of the subject matter is set forth in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which: 
         FIG.  1    is a side view of a trailer with fairings mounted thereto; 
         FIG.  2   , is a rear view of the trailer of  FIG.  1   ; 
         FIG.  3    is a perspective view of the rear portion of the trailer of  FIG.  1   ; 
         FIG.  4    is a perspective view of a top fairing with a bracket assembled therewith in accordance with an embodiment; 
         FIG.  5    is an exploded view of the top fairing of  FIG.  4    and alternative brackets and securing components depicted; 
         FIG.  6    is a perspective view of the rear top portion of a trailer with a top fairing mounted thereto in accordance with an embodiment; 
         FIG.  7    is a side view of the top fairing of  FIG.  6    mounted to the top surface of a trailer comprising a rain gutter; 
         FIGS.  8  and  9    are perspective views of the during its installation, respectively before being mounted to the sides of the trailer and depicting the bracket being secured to the sides of the trailer; 
         FIG.  10    is a side view of a top fairing in accordance with an embodiment; 
         FIG.  11    is a side view of a side fairing in accordance with an embodiment; 
         FIG.  12    is a cross-section view according to a transversal plane of the side fairing of  FIG.  11    mounted to mounting brackets; 
         FIG.  13    is an exploded perspective view of a side fairing and mounting brackets associated therewith adapted to install the side fairing to a side surface of the trailer in accordance with an embodiment; 
         FIG.  14    is a perspective view of an embodiment of a side fairing comprising notches, the side fairing being mounted to the side surface of a trailer comprising corrugations; 
         FIGS.  15  and  16    are respectively a perspective view and a close-up view of a front portion of a top fairing showing a single water inlet in accordance with an embodiment; 
         FIGS.  17  and  18    are respectively a perspective view and a close-up view of a front portion of a top fairing showing a single water inlet in accordance with another embodiment; 
         FIGS.  19  and  20    are respectively a perspective view and a close-up view of a front portion of a top fairing showing a single water inlet in accordance with another embodiment; and 
         FIG.  21    is a perspective view a top fairing with another embodiment. 
     
    
    
     It will be noted that throughout the appended drawings, like features are identified by like reference numerals. 
     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. 
     Recitation of ranges of values and of values herein or on the drawings are not intended to be limiting, referring instead individually to any and all values falling within the range, unless otherwise indicated herein, and each separate value within such a range is incorporated into the specification as if it were individually recited herein. The words “about,” “approximately,” or the like, when accompanying a numerical value, are to be construed as indicating a deviation as would be appreciated by one of ordinary skill in the art to operate satisfactorily for an intended purpose. Ranges of values and/or numeric values are provided herein as examples only, and do not constitute a limitation on the scope of the described realizations. The use of any and all examples, or exemplary language (“e.g.,” “such as,” or the like) provided herein, is intended merely to better illuminate the exemplary realizations and does not pose a limitation on the scope of the realizations. No language in the specification should be construed as indicating any unclaimed element as essential to the practice of the realizations. 
     In the following description, it is understood that terms such as “first”, “second”, “top”, “bottom”, “above”, “below”, and the like, are words of convenience and are not to be construed as limiting terms. 
     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 on  FIG.  1   . 
     Referring to  FIGS.  1  to  3   , the present invention provides for a fairing  110  a back of the trailer  112  that improves aerodynamic performance of the trailer  112  to reduce drag on the trailer  112  when a truck (not depicted, located at the front of the trailer) is hauling the trailer  112 . The fairing  110  comprises a top fairing  168  that is attached to the top surface  136  of the trailer  112 , or the fairing  110  may be a side fairing  170  attached to the side surface  134  of the trailer  112 . Typically, the trailer  112  is provided with side fairings  170  on both of its side surfaces  134 , and with a top fairing  168  on its top surface  136 . The fairing  110  features a leading airflow surface  114  that has a leading radius. The leading airflow surface  114  meets a tailing airflow surface  120  at a meeting location  122  (see  FIG.  10   ), and a common tangent line  124  (see  FIG.  10   ) extends through the meeting location  122  and is tangent to both the leading airflow surface  114  and the tailing airflow surface  120  at this point. The fairing  110  is designed for the air to travel over the leading airflow surface  114  and to follow the tailing airflow surface  120  to result in an optimal reduction of drag on resulting from air led to the rear of the trailer  112  during transport. 
       FIGS.  1  to  3    illustrate a trailer  112  adapted to be hauled by a truck that features at its rear portion fairings  110  in accordance with an exemplary embodiment. The combination of the truck and trailer  112  extends in a longitudinal direction  144  which is the general direction of travel as the truck hauls the trailer  112  forward. The fairings  110  are designed to deflect airflow in an optimal manner around the back of the trailer  112  so that drag on the trailer  112  during travel is optimally reduced. The geometric design of the fairing  110  includes features that result in this optimal reduction of drag. Although three fairings  110  are shown at the back end of the trailer  112 , it is to be understood that the trailer  112  may be outfitted with only one or with two of the fairings  110  in other exemplary embodiments. The fairings  110  are preferably located proximate to the terminal end  174  of the trailer  112 , secured to the trailer  112 , and are forward of the terminal end  174  in the longitudinal direction  144 . In some instances, the fairings  110  may extend rearward of the terminal end  174  in the longitudinal direction  144 . The fairings  110  are located near the terminal end  174  of the trailer  112  because they are designed to affect the flow of air at the back end of the trailer  112  and behind the trailer  112  during travel. Additional fairings (not shown), not specifically discussed herein, can be employed e.g., at the bottom of the trailer  112  or in other locations on the trailer  112  as desired for combined effect on drag of the trailer  112 . 
     Top Fairing 
     With additional reference to  FIGS.  4  to  10   , the top fairing  168  is located at the back end of the trailer  112  so that it is closer to the back terminal end  174  of the trailer  112  than to the front terminal end of the trailer  112 . The top fairing  168  may be spaced some amount forward of the back terminal end  174  in the longitudinal direction  144 , may terminate right at the back terminal end  174 , or may extend slightly rearward from the back terminal end  174  in the longitudinal direction  144 . The top fairing  168  extends almost all the way across the top surface  136  in the lateral direction  146  of the trailer  112  so as to extend about both the right and left side surfaces  134 . It is contemplated by the present application that the top fairing  168  covers the entire width of the trailer&#39;s box, which can reach about between 96″ to 100″, for instance. 
       FIG.  7    is a side view of the back end of the trailer  112  with the top fairing  168  positioned onto the top surface  136  of the trailer  112 . The top fairing  168  has a leading airflow surface  114  that is forward of a tailing airflow surface  120  in the longitudinal direction  144 . The top fairing  168  is typically made of an unibody component mounted to the top surface  136  secured with fixing components to the top surface  136 . The leading airflow surface  114  and the tailing airflow surface  120  may be constant or may vary along the width of the top fairing  168 . In other words, the leading airflow surface  114  and the tailing airflow surface  120  may be measured according to longitudinal planes (e.g., plane  135 ,  FIG.  6   ) characterized by their transversal coordinate relative to a reference, e.g., the side edge of the trailer  112 . The leading airflow surface  114  and the tailing airflow surface  120  may 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 surface  114  and the tailing airflow surface  120  discussed herein may be measured according to any transversal coordinate over the width of the top fairing  168 . It is further to be understood that as used herein, when discussing the orientation of the surfaces  114 ,  120  with respect to angles, radii, locations, ranges, etc. the portion of the surfaces  114 ,  120  that are being measured or discussed are the outer surfaces of the leading airflow surface  114  and the tailing airflow surface  120  and not interior portions, if any, of these surfaces  114 ,  120 . The surfaces  114 ,  120  can 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 surfaces  114 ,  120  over the width of the top fairing  168 . 
     The leading airflow surface  114  has a leading edge  160  that is the forward most portion of the leading airflow surface  114  in the longitudinal direction  144 . Forward of the leading edge  160  is an anchoring flange  142 . The leading airflow surface  114  is oriented, from the anchoring flange  142  parallel to the top surface  136 , with a root angle  116  that is typically from 8 to 22 degrees, and more preferably from 12 to 22 degrees, and preferably about 20.7 degrees. The root angle  116  is oriented rearward in the longitudinal direction  144 . The root angle  116  is measured relative to the top surface of the anchoring flange  142 , itself parallel to the side surface  134 . In this regard, an angle of zero (0) degree refer to a surface parallel to the top surface  136 , and a root angle  116  that is of one-hundred and eighty (180) degrees refers to a leading airflow surface  114  that would be normal to the top surface  136  at the leading edge  160 . The leading airflow surface  114  is curved at a set amount so that the entire leading airflow surface  114  has a single leading radius  127 . The leading radius  127  is in the range from 500 millimeters to 900 millimeters. In more preferred embodiments, the leading radius  127  is 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 surface  114  ends at a meeting location  122  where it meets the tailing airflow surface  120 . The tailing airflow surface  120  is a curved surface that extends from the meeting location  122  to a tailing edge  121 . The tailing edge  121  is about or rearward to the terminal end  174  in the longitudinal direction  144 . In the embodiment shown, the tailing airflow surface  120  is curved at a set amount so that the entire tailing airflow surface  120  has a single tailing radius  128 . The tailing radius  128  is in the range from 500 millimeters to 1800 millimeters. In more preferred embodiments, the tailing radius  128  is from 800 millimeters to 1600 millimeters, and preferably about 930 millimeters. 
     The leading airflow surface  114  and the tailing airflow surface  120  are oriented with respect to one another so that they share a common tangent line  124  that is about the apex (i.e., within the top 5% of the height of the top fairing  168 , and preferably within the 2.5% of its height) and about the center (i.e. within the range of 30% to 70% of the chord  145  measured from the leading edge  160  to the tailing edge  121 , and preferably within the 40% to 60% of the chord  145 ). The meeting location  122  is the point of engagement between the leading airflow surface  114  and the tailing airflow surface  120  and in so far as the common tangent line  124  is common to both of these surfaces  114 ,  120 . This arrangement affords airflow off of the leading airflow surface  114  to channel against the tailing airflow surface  120  with no disruption. The orientation and leading radius  127  of the leading airflow surface  114  and of the tailing airflow surface  120  results in a geometry of the top fairing  168  that causes an air flow to travel downward over the top fairing  168  around the rear of the trailer  112  to reduce dragging force while the truck is hauling the trailer  112  to improve its fuel efficiency. 
     The leading air flow surface  114  is spaced from the top surface  136  so that a gap  152  is present and the portion of the top fairing  168  that is below the leading air flow surface  114  is not in engagement with the top surface  136 . 
     The anchoring flange  142  is attached, typically glued with double-face automotive tape, to the top surface  136 . According to an embodiment, the anchoring flange  142  is glued over the width of the anchoring flange  142  (from about one side edge to about the other side edge of the top surface  136 ) 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 surface  136  of the trailer  112 . 
     The installation of the top fairing  168  involves a bar  126  that extends between the top surface  136  and the surfaces  114 ,  120 , and that extends sideways between the side wall  132  of the top fairing  168  to be secured to a mounting bracket  178  at both ends. The bar  126  can extend over the whole width of the top fairing  168 , and can be secured to the top fairing  168  at locations to reinforce the top fairing against deformation and/or vibration. The bar  126  can be a separate component from the top fairing  168 , or may be permanently assembled to the surfaces  114 ,  120 . 
     It is to be understood that the bar  126  can be a component that is separate from the leading airflow surface  114  and the tailing airflow surface  120 , The bar  126  may be alternatively integral to the top fairing  168 . The bar  126  may be a single bar. The bar  126  may alternatively be made of a plurality of bar sections, either or not joined to each other. The bar  126  may be made of the same material than the portion of the top fairing  168  defining the leading airflow surface  114  and the tailing airflow surface  120 . The bar  126  may alternatively be made or of a different material than the surfaces  114 ,  120 . Typically, the bar  126  presents more rigidity than the surface  114 ,  120 . 
     The bar  126  is shown attached to the top surface  136  through the brackets  178  secured to the top of the trailer  112  on opposite sides in the lateral direction  146  (depicted on  FIG.  6   ), and more precisely close enough to the side edges of the trailer  112  to have the bolts securing the brackets  178  to the trailer  112  not penetrating in the interior compartment of the trailer  112 . The bar  126  is secured to brackets  178 , and an interface between an extending wing  176  and a slot  172  present in the side walls  132  exerts the anchoring flange  142  downward. A top wing  166  of the brackets  178 , presenting itself as an inward folding of a top portion of the brackets  178 , complete the interface of the top fairing  168  with the brackets  178 . The top wings  166  participate in preventing rotation of the top fairing  168 . The described mounting of the top fairing  168  provides some side clearance for transversal adjustment of the top fairing  168 . Accordingly, a single bar  126  provides the required strength to attach the top fairing  168  to the top surface  136 . 
     As discussed, the use of the bar  126  allows the side walls  132 , and consequently the leading airflow surface  114  and the tailing airflow surface  120 , to be secured to the trailer  112  without having to drill holes through the top surface  136 , which could result in rain or contaminants entering the compartment of the trailer  112 . In this manner, the compartment of the trailer  112  is made more secure by the use of the side-mounted brackets  178  and the bar  126  to retain the top fairing  168  to the trailer  112 . Although described as utilizing a single tubular bar  126  to secure the top fairing  168 , 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 surface  120  is adapted for a cantilevered portion to cover a rain gutter located at the rear end of the top surface  136 . The tailing airflow surface  120  may be adjusted to adapt rain gutters of different dimensions. 
     The side walls  132  have a rear edge  138  distant from the tailing edge  121 . The rear edge  138  defines a clearance under a cantilevered portion of the tailing surface  120  allowing the top fairing  168  to adapt to top surfaces having no rain gutter and rain gutters  118  of different dimensions, whereby mounting the brackets  178 , thus the top fairing  168 , farther (for a top surface  136  featuring no rain gutter) or closer (for a top surface  136  featuring a rain gutter  118  of up to e.g., 1⅜ of an inch to have the tailing edge  121  above the rain gutter  118  and reaching the terminal end  174 . 
     According to an embodiment, the rear edge  138  features an upward-rearward slop followed in the direction of the tailing edge  121  by a rearward portion. This shape is adapted to improve clearance while limiting the cantilevered portion of the tailing airflow surface  120  to an acceptable value. 
     According to a preferred realization, the tailing airflow surface  120  may be marked with indications (not depicted) where to cut the tailing airflow surface  120  based on the dimension of the rain gutter  118  to adapt to. 
     According to a preferred realization, the meeting location  122 , where uplift forces are at their maximum, is within 10% of the total chord  145  from the leading edge  160  to the tailing edge  121  relative to the position in the longitudinal direction of the center of the bar  126 . More preferably, it is within 5% relative to the position in the longitudinal direction of the center of the bar  126 . 
     The profile of the top fairing  168  may be defined by the parameters of the leading airflow surface  114  and the tailing airflow surface  120 , including the root angle, characteristics of their meeting, etc. According to a preferred realization, the root angle  116  is 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 radius  127  is in the range from 500 millimeters to 1800 millimeters. In more preferred embodiments, the leading radius  127  is from 500 to 900 millimeters, and preferably from 700 millimeters to 800 millimeters, and preferably about 760 millimeters. The tailing radius  128  is in the same ranges than the leading radius, and preferably about 900 millimeters. The center of curvature of the leading radius  127  is located under the surfaces  114 ,  120  and its longitudinal coordinate is within 20% of the chord  145  relative to the meeting location  122 , and preferably within 10% of the chord  145  relative to the longitudinal coordinate of the meeting location  122 . The center of curvature of the tailing radius  128  is located under the surfaces  114 , 120  and its longitudinal coordinate is within 20% of the chord  145  relative to the meeting location  122 , and preferably within 10% of the chord  145  relative to the longitudinal coordinate of the meeting location  122 . The side fairing tailing angle  129  (see  FIG.  10    for depiction of the top fairing  168  and  FIG.  12    for depiction on the side fairing  170 ) 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 radius  127  over the tailing radius  128  is 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 to  FIGS.  15  to  21   , according to embodiments, top fairings  168  feature an improved water management feature comprising a series of water inlets  194  having a generally funnel-shaped aperture  196  on the anchoring flange  142  extending over the whole depth of the anchoring flange  142  and ending with a e.g., curved opening  198  at the root of the leading airflow surface  114 , wherein the opening  198  has small height  200  and a inlet width  204  providing passage for big water drops to travel from in front of the anchoring flange  142  to under the top fairing  168  and finally reaching e.g., a rain gutter. Accordingly, water falling over the top surface  136 , instead of accumulating in front of the anchoring flange  142 , and travelling over the top fairing  168  and risking falling from the tailing edge  121  at the rear of the trailer  112  on following vehicles, are drained through the rain gutter  118  (see for example  FIG.  7   ). 
     Embodiments includes top fairings  168  featuring from 3 water inlets  194  ( FIG.  21   ) including two partial water inlets on the sides and a central one, and to more than 30 water inlets  194 . According to embodiments, the height  200  of the aperture  196  may vary from about the thickness of the anchoring flange  142  to up to three times the thickness of the anchoring flange  142  with low influence on drag reduction resulting from the use of the top fairing  168 . The present disclosure contemplates different shapes (e.g., straight, curved) and width  202  of side walls  194  for the funnel-shaped apertures  196  and spacing between the side walls  194  of neighbor water inlets  194  being null to a ratio of e.g., four time the width  202 . The present disclosure further contemplates general shapes of the opening  198  from being either straight or having a curved shape, or another shape appropriate in relation with the material in which the top fairing  168  is made of. 
     Side Fairing 
     Referring now to  FIGS.  1  to  3  and  11  to  14   , the side fairing  170  extends in a vertical direction  148  of the trailer  112  along some, but typically not all, of the vertical height of the trailer  112 . The side fairing  170  is typically located closer to the top surface  136  of the trailer  112  than a bottom surface of the trailer  112 . The side fairing  170  may be located at the top surface  136 , or it may be spaced some distance from the top surface  136  in the vertical direction  148 . The side fairing  170  is mounted to the side surface  134  of the trailer  112 . 
     According to an embodiment, the side fairing  170 , which function is to direct the flow of air around the side of the trailer  112  and to an area behind the trailer  112  to result in less drag on the trailer  112  when the trailer  112  is hauled by a truck, has an anchoring flange  142  attached to the side surface  134 , and a leading airflow surface  114  that joins the anchoring flange  142  farther in the longitudinal direction  144 , and a tailing airflow surface  120  that follows the leading airflow surface  114  in the longitudinal direction  144 . 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 surface  134  of the trailer  112  can include corrugations  156  that extend in horizontally in the longitudinal direction  144 . The side fairing  170  may be provided with notches  154  having an ogive-like shape having a pair of parallel edges  157  at the anchoring flange  142  leading to a curved apex  158  distant to the anchoring flange  142 . The notches  154  are adapted for the corrugations  156  to be disposed therein in order to allow the anchoring flange  142  of the side fairing  170  to marry the flat portion of the side surface  134  between the corrugations  156 . 
     The side fairing  170  has a leading airflow surface  114  and a  120  that have similar characteristics than the ones of the top fairing  168 . 
     According to an embodiment, the radii  127 ,  128  of the side fairing  170  are respectively of about 1450 millimeters (or 1449 mm) and of about 900 millimeters (or 923 mm). 
     According to an embodiment, the side fairing  170  is secured to the side surface  134  using a series of mounting brackets  188  having surface-contacting portions  190  and fairing-mounting portions  192  spaced from the side surface  134  such as adapted to provide clearance for corrugations  156  and mounting screw tips. The mounting brackets  188  are adapted for the surface-contacting portions  190  to be secured to the side surface  134  with tape and/or rivets. The side fairing  170  is secured to the fairing-mounting portions  192  with screws. 
     According to a preferred embodiment, the side fairing  170  features recesses  164  for the head of the screw to not extend, or extend only slightly, over its outer surface  114  or  120 . 
     According to embodiment, the side fairings  170  may be mounted to extend beyond the terminal end  174  of the trailer  112 . In some embodiments, hinge notches  184  (of similar shape to the corrugation notches  154 ) are present to provide clearance for hinges when opening the doors of the trailer  112  without the hinges flexing the side fairings  170 . 
     In is to be noted that the design of the top fairing  168  and the side fairing  170  may differ in that their root angle and their radii. However, it is preferred that profiles for the top fairing  168  and the side fairing  170  remain with the ranges listed herein. 
     While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.