Vehicle equipped with a front-inlet, vertical air blade duct
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- HERBAULT PATRICK
- Filing Date
- 2020-03-17
- Publication Date
- 2026-07-31
AI Technical Summary
Existing aerodynamic systems for land vehicles face challenges in efficiently reducing drag while minimizing energy consumption and avoiding interference with engine cooling and airflow, particularly those using compressed gas generators, which are bulky and inefficient.
A vehicle drag reduction system utilizing an air gap duct with a front-facing inlet and upward-ejecting outlet, controlled by a variable geometry, to manage airflow for optimal drag reduction and engine cooling, using a controllable shutter to adjust air intake based on vehicle speed and conditions.
Effectively reduces drag by optimizing airflow without disturbing engine cooling or increasing noise, while enhancing sound insulation and pedestrian protection, and improving weather resistance for the windscreen.
Abstract
Description
Description Title of the invention: Vehicle equipped with an air blade duct Front input-vertical output
[0001] | FIELD OF THE INVENTION TO WHICH THE INVENTION RELATES
[0002] — The invention relates to a drag reduction system, in particular of a land vehicle. EARLIER ART
[0003] = Vehicle aerodynamics has always been a subject of research optimization, in particular of the drag coefficient Cx and the SCX value translating the vehicle's resistance to forward motion as a function of its frontal surface area S.
[0004] During the First World War, Constantin Chilowski sought to influence the flow of the air around a moving shell by a jet exiting perpendicularly to the axis of the shell, with the aim of reducing the air resistance offered to the projectiles.
[0005] — In 2014, the structure of a flying car project evolved further, with the use during the cruise phases of the Chilowski effect, which involves projecting a thin jet of air under pressure, normal to the flow, on the nose and leading edges, then covering the majority of the surface is wetted by the Coanda effect.
[0006] In 2017, patent FR1756685 proposed its application to a land vehicle.
[0007] In this patent, the source of the projected air is a compressed gas generator.
[0008] — This solution appears difficult to implement given the volume of gas to would generate and produce nuisances on board the vehicle.
[0009] By way of example, propelling air at 200 m / s through a 5 mm slit over 1 meter of large would represent 1,000 liters of air per second.
[0010] = Moreover, the aerodynamic gain is fragile insofar as the energy to be expended The energy required to compress and project the air must be less than the energy saved by drag reduction.
[0011] — In fact, the efficiency of such a compressed gas generator is much less than 100 % of a perfect machine. If this generator is driven by the motor, it is already necessary take into account the efficiency of the internal combustion engine, which is much less than 1, to be multiplied by the efficiency of the mechanical compressor is also less than 1. Similarly, if the An alternative involves using a gas-activated turbo-compression system. exhaust from the internal combustion engine.
[0012] — Furthermore, the vertically ejected airflow is located at the front of the front shield and completely disrupts the flow of fresh air that must pass through the air inlets of the grille to reach the engine's aerothermal front panel in order to ensure its cooling dissement. BRIEF DESCRIPTION OF THE INVENTION The vehicle has a drag reduction system comprising an air blade duct whose air inlet faces the front of the vehicle and has an inlet slot a few centimeters high and whose outlet ejects air upwards through an outlet slot a few millimeters to 1 cm high, the air ejection speed being a function of the ratio of the area of the air inlet slot section divided by the area of the air ejection outlet slot section. The ratio of the area of the air inlet slot section divided by the area of the air outlet slot section can be between 4 and 10. The ejection speed of the air at the outlet can be between 150 meters per second and 250 meters per second. As an alternative to a simpler fixed geometry, the height of the air inlet slot can be variable and controlled according to the vehicle speed. In particular, the vehicle may be a land motor vehicle. In this case, the width of the air inlet slot is on the order of the width of the vehicle's aerothermal facade. As for the width of the air ejection slot, it can be between the width of the vehicle's aerothermal front panel and the width of the windshield. The air intake can be fitted as a scoop on the hood but preferably, the air intake is located in the engine compartment. When the air intake is located in the engine compartment and shares the air admitted through the grille, it is advantageous for the system to modulate the distribution of air entering the engine compartment between air intended to cool the engine and air intended to reduce aerodynamic drag. In this case, the system's input parameters are vehicle speed, outside air temperature, and engine temperature. It is preferred that the air be ejected to a height greater than the aerothermal facade in order to avoid disturbing the cooling of the engine. According to one embodiment, the air ejection slot and the front edge of the hood coincide. According to another embodiment, the air ejection slot opens into the vehicle's cowl at the base of the windshield. It is then possible to use the hood as the upper face of the duct, which means that the duct runs partly along the hood. This helps to provide sound insulation from the engine compartment to the outside of the vehicle. This also helps to comply with the standard for pedestrian head impact on the hood. Furthermore, the fact that the air projection at the exit of the ejection slot is positioned in the vehicle's cowl at the base of the windshield contributes to the protection of the windshield against rain. Brief description of the drawings Other features and advantages of the invention will become apparent from the detailed description that follows, for the understanding of which reference should be made to the attached drawings. [fig.1] shows according to the invention a fixed geometry duct of an air blade whose air inlet faces the front of the vehicle and whose outlet ejects air upwards. [fig.2] shows according to the invention a duct of an air blade whose air inlet faces the front of the vehicle with a height adjustable by a controllable flap and the outlet ejects air upwards. [fig.3] shows a conventional motor vehicle from a three-quarter front perspective view. [fig.4] shows a conventional motor vehicle from a side view, showing the interior of the engine compartment. [fig.5] specifically shows the engine compartment of a conventional motor vehicle. [fig.6] shows an example of duct placement with the air intake scooped on the hood. [fig.7] shows an example of front-facing installation of the duct with the air intake in the engine compartment. [fig.8] shows an example of duct placement with the air intake in the engine compartment and the ejection slot coinciding with the front cutout of the hood. [fig.9] shows in perspective a vehicle in the example of the previous duct placement with the air intake in the engine compartment and whose ejection slot coincides with the front cutout of the hood. [fig.10] shows an example of duct placement with the air intake in the engine compartment and the ejection slot in the cowl. DETAILED DESCRIPTION OF THE INVENTION The vehicle (V) has a drag reduction system (S) comprising a duct (C) of an air blade. The air inlet (E) of the duct facing the front of the vehicle has a slot (FE) whose height (HE) is a few centimeters high. The outlet (S) of the duct (C) ejects air upwards through an outlet slot (FS) whose height (HS) is of a dimension of a few millimeters to 1 cm, on the order of magnitude 5 mm. The air ejection velocity is a function of the ratio of the area of the air inlet slot cross-section (FE) divided by the area of the air ejection slot cross-section (FS). The ratio of the area of the air inlet slot (FE) divided by the area of the air outlet slot (FS) can be between 4 and 10. The ejection speed of the air at the outlet can be between 150 meters per second and 250 meters per second. As an example, the height (HE) of the air inlet (E) can be 3 cm, which represents a ratio of 6 for an ejection slot (FS) of a height (HS) of 5 mm. If the vehicle's speed is 90 km / h or 25 m / s, this multiplied by 6 gives 150 m / s. If the vehicle's speed is 120 km / h or 33.33 m / s, this multiplied by 6 gives 200 m / s. If the vehicle's speed is 150 km / h or 41.66 m / s, this multiplied by 6 gives 250 m / s. Figure 1] shows one embodiment of the conduit which is a fixed geometry. In this case, the duct (C) includes an air inlet (E), a fitting (R) which changes the direction of the airflow and an air ejection outlet (S). The air inlet (E) is in this embodiment a prism with trapezoidal bases whose initial height, for example, of 3 centimeters gradually decreases to 5 mm over a distance of about ten centimeters. The fitting (R) has the shape of an elbow to modify the 90° orientation of the incoming airflow captured frontally and exiting vertically. The air outlet (S) thus allows the air to be projected upwards. Of course, the slots (FE) and (FS) represented with rectangular flat sections can in practice be curved according to the volumes of the vehicle in particular the curvature of the front face (FA), the curvature of the hood (CA) and the curvature of the windshield (PB), none of these parts being generally flat. The distance between the upper wall of the duct and the lower wall of the duct can be maintained by pads or thin vertical partitions offering little resistance to the airflow. As an alternative to a simpler fixed geometry, the height (HE) of the air inlet slot (FE) can be variable and controllable according to the vehicle speed (V). This is shown in Figure 2. As an example, the lower face of the air inlet prism (E) is actually a movable flap (VM) pivoting around an axis (A). The height (HE) of the air inlet slot (FE) then becomes controllable by a flap controllable mobile (VM). In a conventional manner, this can involve motorizing the movable flap (VM) by a stepper motor, similar to that of heating / air conditioning unit flaps or active grille flaps. So the ratio, which has become controllable, allows the ejection speed of the air to be managed according to the speed of the vehicle (V), which must remain subsonic to maintain the acceleration effect of the speed. Otherwise, we would have a sonic neck effect which would be detrimental insofar as the resistance to the forward movement of the front air intake would increase without the ejection speed limited to the speed of sound increasing and therefore without any further reduction in drag. In particular the vehicle (V) can be a conventional land motor vehicle as synthetically represented in perspective figure 3 and in side view figure 4 with enlarged view of the engine compartment (CM) figure 5. Most commonly, these are vehicles with internal combustion engines (M), although hybrid or all-electric versions also exist. The control electronics of the system (S) in its controllable version can of course be carried out by a dedicated electronic box, but in modern vehicles it is more sensible for this to be part of the functionalities of the engine control box or of a central cabin box such as an intelligent service box. Figure 3 shows in particular the windscreen (BP) and its width (LP), essentially at its base, with a typical dimension between 1.30m and 1.40m. Depending on the model, the hood (CA) may be as shown, with its hood line (LC) being the front edge of the hood, level with the headlights. The hood (CA) may be shorter with a higher hood line (LC) closer to the windshield (PB). On other models, the hood (CA) may be more prominent and incorporate the grille, with the hood line (LC) extending down to the front bumper. Air intakes (EA) located on the front (FA) help cool the engine. Their number and shape contribute to the visual appearance of the grille, which often plays a role in the brand's visual identity, regardless of its technical function. Figure 4 shows a land vehicle with a thermal engine in side view with internal view of the engine compartment (CM), zoomed in on Figure 5. This engine compartment (CM) is the space between the front face (FA) and the apron (T), and between the lower ground clearance limit which can be materialized by a skid plate or aerodynamic fairing and the hood (CA). Typically, the engine compartment (CM) includes the engine (M) shown without accessories, to be completed notably with its air intake line, its exhaust system and gearbox to make the complete powertrain. It also includes for its cooling an aerothermal front panel comprising a radiator (RA) and a fan (VE). This aerothermal facade has a width (LF) of approximately 80 cm to 1 meter and is placed behind the grille. Fresh outside air arrives frontally at the radiator through the air intake spaces (EA) in the vehicle's grille (V). As for the canopy (A), it represents a different space to house the windshield wiper mechanisms and to serve as the air intake for the air conditioning unit. Figure 6 illustrates a first embodiment of the vehicle (V) drag reduction system (S). In this first embodiment, the air intake of the air intake (E) is located outside the hood, scooping in a manner similar to certain engine intake air intakes of competition models. The air intake (E) can thus be fitted as a scoop on the hood (CA) but preferably the location of the air intake (E) is in the engine compartment (CM). Figure 7 illustrates a second embodiment of the vehicle (V) drag reduction system (S) in which the air inlet (E) is located in the engine compartment (CM) at the front of the vehicle (V). In this case the width (LE) of the air inlet slot (FE) is on the order of the width (LF) of the aerothermal facade of the vehicle (V) in order to make maximum use of the available width, around 1 meter. As shown, the system (S) has a dedicated air intake (E), separate from the air intakes (EA) of the grille for the engine. When, on the other hand, the air intake (E) is located in the engine compartment (CM) and shares the air admitted through the grille, it is advantageous for the system (S) to modulate the distribution of the air entering the engine compartment (CM) between the air intended to cool the engine (M) and the air intended to reduce aerodynamic drag. This distribution can be modulated by a dedicated mobile component (VM). In this case, the system's input parameters are vehicle speed (V), outside air temperature, and engine temperature (M). In particular, engine cooling is prioritized when the vehicle (V) is stopped in city traffic jams during a heat wave. On the contrary, the vehicle's aerodynamics (V) are favored when the vehicle is traveling at high speed in cool weather. It is preferred that the air is ejected at a height greater than the aerothermal facade in order to avoid disturbing the cooling of the engine (M). Figure 8 illustrates a third embodiment in which the air ejection slot (FS) and the front edge (LC) of the hood (CA) coincide. This has the advantage of not creating an additional air ejection line on the hood (CA). The gap usually left between the front face (FA) and the front of the hood (CA) is already a few millimeters and allows the air ejection outlet slot (FS) to be positioned in the same location. Figure 9 illustrates the consequences on the vehicle (V) of the intentional displacement of the hood line (LC) from a technical point of view independent of the design. Figure 10 illustrates a fourth and final embodiment in which the air ejection outlet slot (FS) opens into the canopy (A) of the vehicle (V) at the base of the windscreen (PB). It is then possible to use the hood (CA) as the upper face of the conduit (C) at the level of its connection (R), which means that the conduit (C) runs partly along the hood (CA). This helps to contribute to the sound insulation of the engine compartment (CM) from the outside of the vehicle (V). This also helps to comply with the standard for pedestrian head impact on the hood (CA) in the event of a frontal collision with a pedestrian. Furthermore, the fact that the air projection at the exit of the ejection slot is positioned in the vehicle's cowl at the base of the windshield can contribute to protecting the windshield from rain. Indeed, in the event of rain the speed of raindrops is generally less than 10 m / s and therefore an airflow projected at more than 150 m / s will carry the raindrops upwards, thus partially sparing the windshield (BP). In this configuration, the width (LS) of the outlet slot (FS) will be close to the width (LP) of the windshield (BP). As an example, increasing the height (HE) of the inlet slot (FE) from 3 to 4 centimeters will obtain the same multiplication ratios of around 6 for a height (HS) of 5 mm despite a width (LS) of 133 cm compared to a width (LE) of 1 meter. All the system implementation modes (S) can always be made more sophisticated by controlling at least one moving part (VM). A first control parameter is the vehicle speed (V). On the one hand, the speed of the vehicle, which is that of the inlet speed of the air blade, conditions the opening of a flap (VM) to obtain at a given speed the same outlet speed of the projected air or a setpoint depending on the speed of the vehicle (V). On the other hand, vehicle speed also plays a role in the aerodynamic optimization of the vehicle itself, which is low in the city unless... 50 km / h and importantly on motorways at 130 km / h or more depending on the country. Furthermore, in town at less than 50 km / h, one may wish to limit or inhibit the system, for example, depending on possible noise pollution. Furthermore, climatic conditions can be taken into account to modulate or inhibit the system (S) depending on the weather. This can be done by considering whether or not the windshield wipers are activated. For more sophisticated vehicles, data from the rain sensor (when present) and the outside temperature can be used to modulate or inhibit the system (S) in the presence of rain or snow. Industrial application In terms of industrial application, the drag reduction system according to the invention relates in particular to (V) motor vehicles with (M) internal combustion engines. The present invention is by no means limited to the embodiments described and re-presented, but a person skilled in the art will be able to make any variation in accordance with their spirit for a range of technical solutions in different fields.
Claims
Demands
1. Vehicle (V) characterized in that it has a system (S) comprising a duct (C) of an air gap whose air inlet (E) makes facing the front of the vehicle (V) and includes a slot (FE) of a dimension (HE) of a few centimeters in height and that its outlet (S) ejects air upwards through a slit (FS) of a few millimeters lines at 1 cm height (HS), the air ejection velocity being function of the ratio of the cross-sectional area of the inlet slot (FE) air divided by the cross-sectional area of the ejection outlet slot (FS) air.
2. Vehicle (V) according to claim 1 characterized in that the ratio of the cross-sectional area of the inlet slot (FE) divided by the the surface area of the air ejection outlet slot (FS) can be between 4 and 10.
3. Vehicle (V) according to any one of claims 1 to 2 ca- characterized by the fact that the ejection velocity of the air at the outlet can be between 150 meters per second and 250 meters per second.
4. Vehicle (V) according to any one of claims 1 to 3 ca- characterized by the fact that the height (HE) of the air inlet slot (FE) is variable and controllable depending on the vehicle's speed (V).
5. Vehicle (V) according to any one of claims 1 to 4 ca- characterized by the fact that the vehicle (V) is a motor vehicle terrestrial.
6. Vehicle (V) according to claim 5 characterized in that The air intake (E) is positioned at the front in the com- engine compartment (CM).
7. Vehicle (V) according to any one of claims 5 to 6 ca- characterized by the fact that the air is ejected into the canopy (AV).
8. Vehicle (V) according to claim 7 characterized in that the duct (C) runs partly along the hood (CA) contributing to the sound insulation of the engine compartment (CM) to the outside of the vehicle (V).
9. Vehicle (V) according to claim 7 characterized in that the conduit (C) runs partly along the hood (CA) contributing to compliance with the standard pedestrian head impact on hood (CA).
10. Vehicle (V) according to claim 7 characterized in that the The projection of air at the exit of the ejection slot (FS) contributes to the windshield (WB) protection against rain.