Abstract: The invention relates to a cooling system for a vehicle, the cooling system comprising a cooling fan comprising a ram air turbine disposed in an aperture of a fan shroud, the fan shroud comprising: an opening, a shutter mechanism movable between a closed position in which it closes the opening, and an open position in which it opens the opening so that a ram air flow can pass through the opening, wherein the fan shroud further comprises: a velocity sensor configured to measure ram air flow velocity, a temperature sensor configured to measure ram air flow temperature, and an actuator configured to move the shutter mechanism between the closed position and the open position based on measured ram air flow velocity and measured ram air flow temperature.

Abstract: A ventilation device for a vehicle includes a frame defining an opening and a closure device that includes at least one closure flap extending in the opening. The ventilation device includes a first section having a first external face and at least a second section having a second external face. The external face of the closure flap is formed by the first external face and by the second external face, the first section and the second section extending in continuity of one another. The first section is joined to the second section in a junction region, with a trimming piece that covers at least the junction region on the external face of the closure flap.

Abstract: A thermal energy control apparatus for a hybrid vehicle is capable of efficiently managing thermal energy. The apparatus includes an integrated thermal management (ITM) unit that adjusts a coolant temperature by opening or closing a radiator valve and an active air flap (AAF) unit that adjusts an intake amount of ambient air by opening or closing a flap valve. A cooperative controller cooperatively operates the ITM and AFF units. The cooperative controller determines, based on a coolant temperature, whether a cooperative control mode is to be executed, adjusts an opening degree of the flap valve when the cooperative control mode is a cooperative control mode of the AFF unit, and adjusts an opening degree of the radiator valve when the cooperative control mode is a cooperative control mode of the ITM unit.

Abstract: An apparatus, for controlling a temperature of a vehicle component, such as of an internal combustion engine, by way of a cooling apparatus of the vehicle, includes a displaceable air guide, an actuator, a temperature sensor and a control unit. The control device is adapted so that a partially open air guide protection position is set at least temporarily below an external temperature threshold value for providing a frost warning. A related method is also disclosed.

Abstract: An active grille shutter arrangement having a modular frame. The active grille shutter arrangement includes a primary frame piece defining a width and height of an aperture of the modular frame, wherein in the primary frame piece has a motor housing, and upper frame portion having a first end and a second end, a lower frame portion having a first end and a second end and the motor housing extends between the upper frame portion and the lower frame portion. There is a plurality of secondary frame pieces that are adjustably connected to the primary frame pieces, thereby allowing the width of the modular frame to be adjusted.

Abstract: A vehicle grille assembly includes a body panel and a housing coupled to the body panel. The housing includes a front surface and a rear surface. The rear surface defines a cutout. A display assembly is disposed adjacent to the housing and aligned with the cutout. The display assembly includes a light source disposed on a circuit board and a heatsink coupled to the circuit board. The light source emits light towards the front surface of the housing. A deflector is disposed adjacent to the display assembly and includes a base and a guide wall extending vertically from the base. The deflector includes a first surface and a second surface. The deflector defines a first airflow path and a second airflow path.

Abstract: A motor vehicle front end has a heat exchanger and a cooling-air mechanism for controlling a supply of air to the heat exchanger. The cooling-air mechanism includes: a downwardly opening air inlet opening; and an air flap, which corresponds to the air inlet opening, and which, at its top edge, is articulatable on a body part in a pivotable manner via a pivot joint. The air flap is configured such that, in its closed position, it closes off the air inlet opening, and in its operative position, it opens up the air inlet opening, and as seen in a direction of travel of the motor vehicle, is situated in front of the air inlet opening.

Abstract: The present invention relates to a device (1) for sealing a motor vehicle front face air intake, comprising: a supporting frame (5) in which is installed at least one set of flaps (3) pivoting about pivot pins (A), at least one control element (13) configured to control the positioning of the flaps (3), the supporting frame (5) including at least one row of bearings (51) receiving the pivot pins (A) arranged on a side pillar (5b), the sealing device (1) including at least one locking element (60) covering a row of bearings (51), said locking element (60) comprising a body and at least one connection member (61) including a base connecting it to said body of the locking element (60) and a head wider than said base, said side pillar (5b) including at least one slot (52) opening onto an outer side of said side pillar (5b) and preferably having a shape complementing said at least one connection member (61), said at least one connection member (61) being inserted into the at least one slot (52).

Abstract: An air flap apparatus for a motor vehicle, encompassing a frame having a flowthrough opening, at least one air flap mounted movably relative to the frame that projects into the flowthrough opening; the at least one air flap being displaceable between closed and open positions in order to modify a gas quantity flowing per unit time, with a predefined flow impingement, through the flowthrough opening; the at least one air flap decreasing a flowthrough-capable cross section of the flowthrough opening greater in the closed position than in the open position; the air flap apparatus further encompassing a motion drive system that is coupled to the at least one air flap to drive the at least one air flap between the closed and open positions, at least one air flap, constituting a light-emitting air flap, having at least one light exit surface to radiate light to an external environment of the light-emitting air flap, the light-emitting air flap having at least one light-guiding light guidance component to guide ligh

Abstract: An apparatus is provided. The apparatus includes a heat exchanger providing heat transfer between a first medium and a second medium. The apparatus also includes a movable aperture integrated onto a face of the heat exchanger and regulating a flow of the first medium based on a position of the movable aperture. The apparatus further includes an actuator controlling the position of the movable aperture.

Abstract: A portable removable air-cooling accessory device for an air cooled engine, in a piston and/or light aircraft, and a method of using the air-cooling accessory to cool the engine of the light aircraft are described. The portable removable air-cooling accessory device includes at least a fan assembly, a housing having an enclosure forming and airflow channel, a rechargeable battery, and electrical components for controlling and monitoring the portable removable air-cooling accessory device is placed on the opening of the oil access door or the engines air cooling inlets to provide cooling airflow over the engine when a hot start scenario is anticipated.

Abstract: An active grille shutter arrangement having a modular frame. The active grille shutter arrangement includes a primary frame piece defining a width and height of an aperture of the modular frame, wherein in the primary frame piece has a motor housing, and upper frame portion having a first end and a second end, a lower frame portion having a first end and a second end and the motor housing extends between the upper frame portion and the lower frame portion. There is a plurality of secondary frame pieces that are adjustably connected to the primary frame pieces, thereby allowing the width of the modular frame to be adjusted.

Abstract: Disclosed is a ventilation flap assembly for a vehicle, in particular a motor vehicle (8), the assembly having at least one first and one second ventilation flap (2, 2?) in addition to an actuating element (3). Each of the first and the second ventilation flaps (2, 2?) can be moved from a first position into a second position, in order to allow the passage of a quantity of air, which differs in the second position in comparison to the quantity of air in the first position, through an air opening (83, 84) of the vehicle. The actuating element (3) is used to move both the first and the second ventilation flaps (2, 2?) and said actuating element (3) is designed, when actuated, to firstly move the first ventilation flap (2) from its first position into its second position and only then to move the second ventilation flap (2?) from its first position into its second position.

Abstract: An engine includes an exhaust-gas purification device. The exhaust-gas purification device purifies exhaust gas. The exhaust-gas purification device includes electrical components. The electrical components detect the states of the exhaust-gas purification device. The engine includes a cooling-water circulation mechanism for circulating cooling water for the engine. Further, a portion of the cooling water circulated by the cooling-water circulation mechanism cools the electrical components.

Abstract: An active grille shutter arrangement having a modular frame. The active grille shutter arrangement includes a primary frame piece defining a width and height of an aperture of the modular frame, wherein in the primary frame piece has a motor housing, and upper frame portion having a first end and a second end, a lower frame portion having a first end and a second end and the motor housing extends between the upper frame portion and the lower frame portion. There is a plurality of secondary frame pieces that are adjustably connected to the primary frame pieces, thereby allowing the width of the modular frame to be adjusted.

Abstract: An active grille shutter arrangement having a modular frame. The active grille shutter arrangement includes a primary frame piece defining a width and height of an aperture of the modular frame, wherein in the primary frame piece has a motor housing, and upper frame portion having a first end and a second end, a lower frame portion having a first end and a second end and the motor housing extends between the upper frame portion and the lower frame portion. There is a plurality of secondary frame pieces. The modular frame of the active grille shutter arrangement is formed by the connection of the primary frame piece in the secondary frame piece, wherein the modular frame defines the aperture. The active grille shutter arrangement further includes a plurality of vanes rotatably positioned between the first end cap and the second end cap for controlling the amount of air flowing through the one or more apertures of the modular frame.

Abstract: Disclosed is an engine temperature regulating device installed to a cool air inlet of a casing of an engine. The engine temperature regulating device includes a power source, a link rod module connected to the power source, a control module and a fan cover module including a fixed casing and a movable casing. The control module is provided for detecting a temperature when the engine is turned on to control the power source to drive the link rod module, so as to control the rotation of the connected movable casing and further adjust an air intake hole of the fixed casing to a smooth or obscured state.

Abstract: A cooling fan control system is provided. The system includes a sensor unit that includes a temperature sensor that generates a first output value corresponding to a coolant temperature and an air-conditioner pressure transducer that generates a second output value corresponding to an air-conditioner pressure and a cooling control portion. The cooling control portion generates a control condition based on the first output value and the second output value and adjusts a rotation speed of a cooling motor based on the control condition. The control condition includes a target control condition formed as a region including a cross point of the first output value and the second output value. The cooling control portion adjusts the rotation speed of the cooling motor to cause the first output value and the second output value to correspond to the target control condition.

Abstract: An active grille shutter arrangement having a modular frame. The active grille shutter arrangement includes a primary frame piece defining a width and height of an aperture of the modular frame, wherein in the primary frame piece has a motor housing, and upper frame portion having a first end and a second end, a lower frame portion having a first end and a second end and the motor housing extends between the upper frame portion and the lower frame portion. There is a plurality of secondary frame pieces that are adjustably connected to the primary frame pieces, thereby allowing the width of the modular frame to be adjusted.

Abstract: Provided is a radiator system (1) for a vehicle comprising a radiator device (2) for cooling at least one vehicle component of the vehicle, and at least one regulation device (10) for regulating an airflow (4) to the radiator device (2) wherein the regulation device (10) comprises at least one support element (20) for the acceptance of at least one cover element (15), and wherein the airflow (4) is guidable to the radiator device (2) through at least one opening (5) of the regulation device (10). It is provided that the regulation device (10) is directly assembled at the radiator device (2) in a way that the airflow (4) is guidable to the radiator device (2) directly through the regulation device (10).

Abstract: An adjustment device for adjusting an air inlet of a motor compartment of a motor vehicle between at least a first position in which the air inlet is substantially open and a second position in which the air inlet is substantially closed, comprising a drive unit for adjusting the air inlet between at least the first position and the second position, further comprising an auxiliary unit which is arranged for adjusting the air inlet in case of a calamity for bringing the air inlet to a predefined position, comprising at least one energy storage element.

Abstract: An air control system with an integrated diagnostic device for a motor vehicle includes: a carrier structure, an air output opening, a closing element arrangement with one or several closing elements adjustably placed on the carrier structure, a power unit which is constructed to adjust the closing element arrangement in an adjustment movement, a diagnostic device to acquire information about the condition of the closing element arrangement, an interface to convey data at least from the diagnostic device to another device, wherein for at least one closing element of the closing element arrangement the air control system also includes a resistance element associated with said closing element which is constructed to temporarily change the torque or force required in a predetermined phase of the adjustment movement for the adjustment of the closing element arrangement, wherein the diagnostic device acquires at least one operating parameter of the power unit as information about the status of the closing element

Abstract: A blocker door assembly which may be for a cooling system that may be applied to a gas turbine engine includes a plurality of blocker doors circumferentially spaced about an engine axis. Each blocker door is constructed and arranged to move in a circumferential direction to, at least in-part, control air flow through a passage in an adjacent fixture. A sync-ring is concentrically located about the engine axis, disposed in an annular first duct in direct communication with each passage, and engaged to each one of the plurality of blocker doors for simultaneous operation. The sync-ring is aero-dynamically shaped to reduce surrounding airflow resistance.

Abstract: An air-guiding device (7) can be arranged in a wheel house of a motor vehicle and has a plurality of slats (12). Each slat (12) has at least one first region (11.1, 11.3) with a first profile and at least one second region (11.2, 11.4) with a second profile. The respective profile of the respective region (11) of the respective slat (12) is matched to the respective flow conditions present by a respective shaping and a respective angle of attack. Therefore an air stream approaching the slats (12) has to overcome a reduced aerodynamic drag when passing through the respective slats (12).

Abstract: Disclosed herein are systems for controlling the amount of airflow across a radiator within an aerial vehicle radiator duct. A rigid member of a moveable flow restrictor is rotatable between an open position and a closed position. While subject to a g-force less than a threshold value in a triggering direction, the rigid member is oriented in the open position and, while subject to a g-force greater than the threshold value in the triggering direction, the rigid member is oriented in the closed position. The amount of the airflow across the radiator while the rigid member is in the open position is different than the amount of the airflow across the radiator while the rigid member is in the closed position.

Abstract: An active grille shutter arrangement having a modular frame. The active grille shutter arrangement includes a primary frame piece defining a width and height of an aperture of the modular frame, wherein in the primary frame piece has a motor housing, and upper frame portion having a first end and a second end, a lower frame portion having a first end and a second end and the motor housing extends between the upper frame portion and the lower frame portion. There is a plurality of secondary frame pieces. The modular frame of the active grille shutter arrangement is formed by the connection of the primary frame piece in the secondary frame piece, wherein the modular frame defines the aperture.

Abstract: An external active air flap apparatus of a vehicle is provided The external active air flap apparatus removes the gap between the air flaps disposed vertically after sealing an air passage of a radiator grill by the air flaps and minimizes the gap between the air flaps and the radiator grill, thereby improving aerodynamic performance of the vehicle. The external active air flap apparatus includes an air flap positioned at a rear of a radiator grill that rotates to open and close an air passage of the radiator grill. Further, a flap fixing mechanism is mounted on the radiator grill and the air flap contracts the air flap with the radiator grill by applying a wind pressure to the air flap operated to seal the air passage.

Abstract: A work vehicle having a hood for covering an engine room is disclosed. The engine room has a first region and a second region partitioned from each other, the engine room being configured such that air can be introduced from outside of the hood to the first region. A radiator is disposed in the first region, and air flows through the radiator from the first region to the second region. In the second region, the engine and an accessory unit for the engine are provided. The work vehicle includes an adjusting device for adjusting an amount of the air that flows from the first region to the second region.

Abstract: A screen assembly for a work vehicle is disclosed. The screen assembly may generally include a screen defining a plurality of screen openings for receiving an airflow therethrough. In addition, the screen may define a flap opening. The screen assembly may also include a flap pivotally coupled to the screen at the flap opening. The flap may be configured to be moved to a closed position when the airflow through the screen is in a first direction and to an opened position when the airflow through the screen is in a second direction.

Abstract: A system for controlling a flow rate of air into a vehicle engine compartment may include a radiator cooling coolant, a coolant inflow tank provided to one side of the radiator and temporarily storing coolant that cools an engine, a coolant exhaust tank provided to the other side of the radiator and temporarily storing coolant circulating past a cooling fin of the radiator from the coolant inflow tank, Phase Change Material (PCM) tanks provided to an exterior side of the coolant inflow tank and coolant exhaust tank and storing a phase change material heat-exchanging with the coolant stored in the coolant inflow tank and the coolant exhaust tank and a conversion device converting a phase of the phase change material.

Abstract: Provide is a construction machine allowing an air cleaner to be located entirely low while securing dust-discharge function thereof, with no risk of adverse effects such as diffusion of dusts and complication in structure. The construction machine includes an engine and an air cleaner connected to an intake-side portion of the engine to filter intake air. The air cleaner includes an air-cleaner main body which filters the intake air and an evacuator which discharges dusts separated from the intake air and protrudes downward beyond the air-cleaner main body. The air-cleaner main body is placed on an air-cleaner placement surface, the evacuator protruding downward beyond the air-cleaner placement surface at a position deviated outward from the air-cleaner placement surface.

Abstract: An active grille shutter arrangement having an assembled modular frame. The assembled modular frame includes an upper frame portion and a lower frame portion each having a first end and a second end. A first end cap is connectable to both the first end of the upper frame portion and the first end of the lower frame portion. The connection between the first end of the upper frame portion and the first end of the lower frame portion includes an upper bar end joint formed on the front end of the upper frame portion and a lower bar end joint formed on the first end of the lower frame portion. The upper bar end joint slides into an upper bar end cap joint formed on the first end cap and the lower bar end joint slides into a lower end cap joint formed on the first end cap.

Abstract: A freeze detecting device for an active shutter of a vehicle includes an engine control unit that outputs an opening signal, opens an active shutter, takes in travelling wind to an engine compartment, and inhibits heat damage when an external air temperature is at or below a freezing determination temperature and also a load state is high. On the other hand, when an opening signal is output from the engine control unit but the active shutter does not perform an opening action, a determination of being frozen solid is made, a warning is displayed on the display to warn the vehicle driver.

Abstract: A first blowing section is arranged inside a cab body on a right side, and blows cool air or warm air. A second blowing section is arranged inside a cab body on a left side, and blows cool air or warm air. An inlet, a first vent, and a second vent are formed in a box body of a distribution box. The inlet opens toward the left side and introduces cool air or warm air from an air-conditioning unit. The first vent opens toward the right side. The second vent opens downward. A first duct, which is connected to the first vent, supplies the first blowing section with cool air or warm air. A second duct, which is connected to the second vent and extends beneath a seat, supplies the second blowing section with cool air or warm air.

Abstract: A system includes a sump, a pump having a steady-state speed, a fluid component that receives the fluid from the fluid pump, and a controller. The controller detects a soak condition of the system in which the pump load is low as fluid is moved into vacated fluid passages. The steady-state speed of the pump is temporarily increased by adding a calibrated overspeed value to the steady-state speed, for a calibrated duration. The controller reduces the pump speed to the steady-state speed after the calibrated duration has elapsed. A method includes detecting the soak condition and temporarily increasing the steady-state speed via the controller by adding the calibrated overspeed value to the steady-state speed, for a calibrated duration, when the soak condition is detected. A control system includes a processor and storage medium having instructions embodying the method, with detection of the soak condition provided via measurement of fluid temperature.

Abstract: A grille shutter control device is provided with a control section configured so as to open and close a shutter adapted to be provided in an air introduction path for introducing air ahead of the vehicle into an engine compartment. The grille shutter control device drives and controls first and second drive units. The grille shutter control device is provided with: an abnormality detecting section configured to detect an abnormality in the operation of the shutter on the basis of the condition of the shutter after the start of operation thereof; and an informing section for informing, on the basis of an abnormality in the operation detected by the abnormality detection section, the user of the abnormality in the operation of the shutter.

Abstract: A control device includes target temperature setting means, feedback control means, and shortcut control means. The target temperature setting means sets a target temperature (?) of a coolant according to a temperature state of an internal combustion engine. The feedback control means controls a control valve in such a manner that a coolant temperature is the target temperature (?). The shortcut control means controls the control valve in such a manner that, when the internal combustion engine is in a cold state, the target temperature setting means sets as the target temperature (?) a warming-up temperature (?) higher than a feedback control temperature (A or B) which is set during feedback control.

Abstract: An opening/closing control device for a shutter of a vehicle is provided which is capable of appropriately opening and closing the shutter according to the traveling conditions of the vehicle, and improving fuel economy while maintaining excellent maneuverability of the vehicle. When the detected vehicle speed is not smaller than a predetermined first reference value and smaller than a second reference value, the shutter is closed to improve fuel economy. On the other hand, when the vehicle speed is not smaller than the second reference value, the shutter is opened. Further, at this time, a condition for opening the shutter is set according to at least one of a grip force of the vehicle and a steering angle. This maintains excellent vehicle maneuverability.

Abstract: An engine cooling system may include a housing forming an enclosed duct having an air intake opening, at least one heat exchanger positioned within the duct such that ambient air entering the air intake opening contacts the at least one heat exchanger, at least one radiator circulating coolant for the engine, at least one radiator positioned in the duct such that ambient air entering the air intake opening contacts at least one radiator, and the duct configured to include an exhaust opening positioned downstream of the at least one heat exchanger and the at least one radiator, such that ambient air flows in the air intake opening, through the duct to contact the heat exchanger and the radiator, and exits the duct through the exhaust opening.

Abstract: Provided is a shutter device having a fail-safe function to prevent occurrence of overheating even when an actuator becomes inoperable. The shutter device includes a shutter valve (11) which opens and closes an air port, a lever (14a) having one end connected to a rotating shaft (16) of the shutter valve and the other end connected to an actuator (12), and biasing means which biases the shutter valve in an opening direction. Opening/closing of the shutter valve is controlled by the actuator rotating the lever when opening of the shutter valve is between the fully-open and predetermined opening, and the shutter valve is closed by wind pressure of travelling wind when the opening of the shutter valve is between the predetermined opening and the fully-closed.

Abstract: A thermal management module includes a motor with an output shaft, and a gear train connecting the output shaft to a driven gear connected to a valve for controlling coolant flow in a coolant system. At least one grille shutter is movable between an open position allowing air through the grille shutter and a dosed position preventing air through the grille shutter. A linkage connects the at least one grille shutter to the output shaft or the gear train, so that the motor is operable to control a valve operating position of the valve and a shutter operating position of the at least one shutter.

Abstract: A wax-type thermostat for the cooling system of an internal combustion engine (ICE) is provided. The cooling system includes a radiator and a coolant loop circuit linking the radiator to the internal combustion engine, and having a by-pass conduit. The thermostat includes a thermostat body with a radiator inlet, an ICE inlet, via the by-pass conduit, and an ICE outlet. The thermostat further includes a piston integral to a closure element that opens or close a thermostat internal pathway connecting the radiator inlet to the ICE outlet, and a wax chamber thermally connected to the coolant within the thermostat body. The thermostat includes a first spring to return the closure element towards its closing position, and means for moving the piston when a volume variation in the wax occurs.

Abstract: Methods and systems are provided for reducing corrosion of a charge air cooler and preventing engine misfire due to condensate formation. In response to a condensate forming region in a charge air cooler, a grille shutter system is adjusted, moving the condensate region to a different location in the charge air cooler. Grille shutter orientation may also be controlled in response to vehicle operating conditions and condensate-forming weather conditions.

Abstract: A method is disclosed for heating a liquid supplied to an engine of a motor vehicle by a pump when the temperature of the liquid is low, thereby reducing the operating efficiency of the engine. The method comprises inefficient operation of the pump by constricting flow to create heat that is transferable to the liquid. Inefficient operation of the pump is enacted when service brakes are applied and the vehicle is decelerating to minimize negative impact on fuel economy and overall engine efficiency.

Abstract: An air directing device for motorcycles with an engine air cleaner bottom housing. An external air plenum forms both an engine-air intake channel and a rearward cylinder cooling channel by coupling (e.g., directly attaching) the external air plenum to an air filter. The external air plenum defining a forward-facing inlet port and an engine-facing outlet port (disposed over a portion of the rearward cylinder) with the two channels in fluid communication with the inlet port.

Abstract: A failure determination device capable of performing failure determination for a shutter device of a vehicle with accuracy in a short time period. In an engine room of a vehicle, a condenser for a refrigeration cycle for an aircon is provided and at a front grille of the vehicle, a grille shutter device is provided for introducing ambient air for cooling the condenser into the engine room by opening a grille shutter. According to the failure determination device of the shutter device, a pressure of the refrigerant discharged from the condenser is detected as a refrigerant pressure. A failure of the grille shutter device is determined based on the refrigerant pressure, which changes at a large rate according to the opening/closing of the grille shutter, enabling failure determination with accuracy in a short time period.

Abstract: An air intake adjusting system for a motor vehicle includes a plurality of struts which are arranged at distances from one another and can each be rotated about an axis of rotation such that, in a first position of the struts, the air intake adjusting system is open and, in a second position of the struts, the air intake adjusting system is closed. The struts each have a rotating section, through which the axis of rotation of the respective strut extends, and a flap section, which extends from the rotating section and, in the second position, rests against the rotating section of an adjacent strut. The rotating sections of the struts each have a first side and a second side which, when the struts are in the second position, converge against an intended approach flow direction of the air intake adjusting system such that they form an approach flow edge.

Abstract: To provide a vehicle front portion structure that efficiently cools a cooling unit. A duct, whose upper end opens at a cowl panel side and whose lower end opens above a vehicle front side of a cooling unit, is provided at a vehicle front portion. A blower fan is provided at an intermediate portion of the duct. The blower fan is rotated, and external air, that has been drawn-in from a cowl side, can be blown as cooling wind from a lower end side of the duct toward a condenser and a radiator. Therefore, heat exchange efficiency can be improved as compared with a case of only traveling wind that is introduced in from an opening of a front bumper cover.

Abstract: A method of controlling airflow through a grille on a front end of a vehicle comprising the steps of: detecting vehicle operating conditions; determining a desired percentage of airflow through the grille based on the desired operating conditions; actuating grille airflow shutters to an open position for the determined desired percentage of a predetermined time interval; and actuating the grille airflow shutter to a closed position for a remaining percentage of the predetermined time interval.

Abstract: A system for removing heat from the engine compartment (9) of a heavy duty truck. A first ventilating system removes heat from the radiator. It is isolated from a second ventilating system that removes heat from the engine compartment. The first system takes heat from the radiator through a plenum by centrifugal squirrel cage blowers, and is directs it out to ambient by ductwork. The second system draws ambient air generally from back to front of the engine compartment, preferably by cowl induction, without the use of ram air from the vicinity of the radiator. The exits of the two systems are into a slip stream of the heavy duty truck, and the exit of the second ventilating system is into a slip stream of the first, to scavenge air out of the engine compartment.