Rankine vortex particle separator systems and methods

A particle separator assembly includes an airbox providing an outer tapered portion tapering from a first section having a first cross sectional area to a first opening having a second cross sectional area less than the first cross sectional area. The example assembly includes a flow diverter providing an inner tapered portion that tapers to a second opening. The example assembly includes an air filter housed by the airbox, the air filter is spaced from the second opening in a first direction, and the first opening is spaced from the second opening in a second direction opposite the first direction.

BACKGROUND

Vehicles, such as automobiles, heavy trucks, agricultural vehicles, commercial vehicles, as well as water and air vehicles, include air intake systems for providing air flow to their engines.

SUMMARY

A particle separator assembly according to an example of this disclosure includes an airbox providing an outer tapered portion tapering from a first section having a first cross sectional area to a first opening having a second cross sectional area less than the first cross sectional area. The example assembly includes a flow diverter providing an inner tapered portion that tapers to a second opening. The example assembly includes an air filter housed by the airbox, the air filter is spaced from the second opening in a first direction, and the first opening is spaced from the second opening in a second direction opposite the first direction.

In a further example of the foregoing, the flow diverter is a separate, drop-in component.

In a further example of any of the foregoing, the first opening and second opening are centered about a common axis.

In a further example of any of the foregoing, the first opening has a circular cross section.

In a further example of any of the foregoing, the second opening has a circular cross section.

In a further example of any of the foregoing, the second opening has a third cross sectional area greater than the second cross sectional area.

In a further example of any of the foregoing, a radially outer surface of the inner tapered portion has a concave curvature, and a radially inner surface of the inner tapered portion has a convex curvature.

In a further example of any of the foregoing, a duckbill is provided at the first opening.

An air intake system according to an example of this disclosure includes an airbox providing an outer tapered portion tapering from a first section having a first cross sectional area to a first opening having a second cross sectional area less than the first cross sectional area. A flow diverter provides an inner tapered portion that tapers to a second opening. An air filter is housed by the airbox, the air filter is spaced from the second opening in a first direction, and the first opening is spaced from the second opening in a second direction opposite the first direction. An intake duct is fluidly connected to the airbox at a first connection opening. A clean air duct is fluidly connected to the airbox at a second connection opening spaced from the first connection opening in the first direction.

In a further example of the foregoing, the flow diverter is a separate, drop-in component.

In a further example of any of the foregoing, the first opening and second opening are centered about a common axis.

In a further example of any of the foregoing, the intake duct is positioned in an offset position relative to a center of the airbox.

In a further example of any of the foregoing, the second opening has a third cross sectional area greater than the second cross sectional area.

In a further example of any of the foregoing, a radially outer surface of the inner tapered portion has a concave curvature, and a radially inner surface of the inner tapered portion has a convex curvature.

In a further example of any of the foregoing, the first opening has a circular cross section.

In a further example of any of the foregoing, the second opening has a circular cross section.

In a further example of any of the foregoing, a duckbill is provided at the first opening.

These and other features may be best understood from the following specification and drawings, the following of which is a brief description.

DETAILED DESCRIPTION

This disclosure relates generally to air intake and particle separator systems and methods for providing air flow to vehicle engines. In some examples, the particles may include sand, dust, or other like solid or liquid particles.

FIG.1illustrates an example air intake system10for a vehicle. The vehicle may include any of automobiles, heavy trucks, agricultural vehicles, commercial vehicles, as well as water and air vehicles, in some examples. The example intake system10includes an intake duct12, a particle separator assembly14, and a clean side duct16. In the example shown, the general flowpath of air flows from the intake duct12, through the particle separator assembly14, and then through the clean side duct16, and eventually to the vehicle engine19(shown schematically).

FIG.2illustrates an exploded view of the example intake system10shown inFIG.1. The example particle separator assembly14includes an airbox17that houses a drop-in flow diverter18and an air filter20. That is, in some examples as shown, the flow diverter18is a drop-in component separate from the airbox17. The airbox17may provide an outer tapered portion22tapering to an opening23. The flow diverter18may provide an inner tapered portion24tapering to an opening26. In some examples, as shown, when assembled, the inner tapered portion24is at least partially nested within the outer tapered portion22. The example airbox17includes a connection opening27for fluidly connecting to the clean side duct16and a connection opening29for fluidly connecting to the intake duct12. In some examples, the opening26has a greater cross-sectional area than the opening23. The smaller opening23makes the axial trajectory turn towards the larger main airflow outlet, without stopping the swirling motion.

FIG.3Aillustrates a horizontal section view through the system10. As shown in the example, the air enters the airbox17from the intake duct12and swirls around within the airbox17. In some examples, as shown, the air swirls counterclockwise when viewed from above as shown. In some examples, as shown, the intake duct12is positioned in an offset position relative to the center of the airbox17. In some examples, the offset position allows air flowing from the intake duct12and into the airbox17to flow adjacent a side surface25of the airbox17. The example offset positions aid in initiating the swirling airflow shown, the benefit of which is discussed further below.

In some examples, as shown, the opening23has a circular cross section to assist in the swirling airflow. In some examples, the opening26may also have a circular cross section, but other shapes are contemplated, such as the opening23being circular and the opening26being non-circular.

FIG.3Bschematically illustrates an example of the offset of the intake duct12and opening29with respect to the airbox17. There is a maximum circle CC inscribed within the airbox17in the cross-sectional plane shown and having a center C. The duct12and opening29are positioned such that most of the airflow F entering the airbox from the intake duct12is directed outside of the center C in order to initiate a swirling airflow.

Referring toFIG.4, the air gradually flows to lower and lower levels (with reference to the orientation shown inFIG.4) in a swirling flow between the airbox17and the flow diverter18. Specifically, the air flows between the outer and inner tapered portions22,24in a swirling motion. As the air flow path gets lower relative to the flow diverter18, the swirl diameter slowly reduces due to the outer tapered portion22, increasing the air's flow velocity, and forcing the air into a central portion21of the outer tapered portion22below the flow diverter18. At the higher velocity, sudden vertical acceleration in the airflow separates the heavier particles from the main air trajectory, i.e., the heavier particles within the air cannot make this upward turn, so they collect at the opening23, while the cleaner air rises when it reaches the central portion21, while still swirling. The air then flows upward through the interior portion of the flow diverter18and then flows across the air filter20and to the clean side duct16. The flow diverter18therefore acts as a particle separator on the airflow prior to the airflow reaching the air filter20.

In some examples, as shown, a duckbill30may be provided at the opening23for removal of the settled particles. In some examples, the duckbill30may be any of the one or more of the embodiments disclosed in U.S. Patent Application Publication No. US 2021/0236975 (priority applications 62/969,717 and Ser. No. 17/167,439) incorporated herein by reference.

Referring toFIGS.3A and4, the air swirls counterclockwise as it flows down toward the opening23and then as it flows upward through the central portion21. However, since the main trajectory of the airflow changed from downwards to upwards, a double-vortex type flow is created. That is, as the main trajectory of the flow changes from downward to upward, the swirl switches from Right-Hand swirl to Left-Hand swirl (this can be visualized by pointing one's thumb towards the main trajectory of the airflow and one's fingers pointing towards the swirling direction). This makes the flow a Rankine (or double) vortex.

FIG.5illustrates a cross sectional view of the example flow diverter18and outer tapered portion22. The example flow diverter18provides the inner tapered portion24, tapering to the opening26at the bottom of the inner tapered portion24(with respect to the orientation in the figure). As shown in the example, the opening23of the outer tapered portion22is below the opening26with respect to the orientation shown.

Referring back toFIG.4, the air flows in a spiraling flowpath downward along the inner surface of the outer tapered portion22, and heavy particles from the air collect at the opening23. The opening23may be covered with a duckbill30or similar feature that can be periodically removed to access the opening23for cleaning. As the airflow reaches the central portion21, it begins to spiral upwards through the opening26provided by the inner tapered portion24. The air may then flow upward across the air filter20before exiting the airbox17. In some examples, there may be one or more additional components (not shown) adjacent the air filter20, such as a Hydrocarbon absorber in some examples.

In some examples, as shown inFIG.5, the outer surface32of the inner tapered portion24has a concave curvature, while the inner surface33has a convex curvature. In come examples, as shown, the openings23and26are centered on a common axis A.

In some examples, the flow diverter18is a drop-in piece, such that the system10also functions without the flow diverter18. In this regard, it may be simple and inexpensive to tune to increase or reduce the separator efficiency and flow restriction as needed, by providing or omitting the flow diverter18.

FIG.6illustrates an exploded view of an example air intake system110substantially similar to the example air intake system10, except that it does not include a flow diverter. Applicant has determined that the system110achieves some separator efficiency due to the taper of the airbox117and the offset of the intake duct112. The system110may also achieve reduced flow restriction compared to the air intake system110in some examples.

An example particle separator system can be said to include an airbox providing an outer tapered portion tapering from a first section34(seeFIGS.2,5) having a first cross sectional area to a first opening23having a second cross sectional area (see cross sectional area of the opening23shown inFIG.3A) less than the first cross sectional area. A flow diverter provides an inner tapered portion that tapers to a second opening. An air filter is housed by the airbox, and the air filter is spaced from the second opening in a first direction D1(FIGS.4and5). The first opening is spaced from the second opening in a second direction D2opposite the first direction D1.

An example air intake system can be said to include an airbox providing an outer tapered portion tapering from a first section34(seeFIG.5) having a first cross sectional area to a first opening23having a second cross sectional area see cross sectional area of the opening23shown inFIG.3A) less than the first cross sectional area. A flow diverter provides an inner tapered portion that tapers to a second opening. An air filter is housed by the airbox, and the air filter is spaced from the second opening in a first direction D1(FIGS.4and5). The first opening is spaced from the second opening in a second direction D2opposite the first direction D1. An intake duct is fluidly connected to the airbox at a first connection opening. A clean air duct fluidly connected to the airbox at a second connection opening spaced from the first connection opening in the first direction.

The foregoing description shall be interpreted as illustrative. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. Various examples of the disclosure have been described. Any combination of the described systems, operations, or functions is contemplated. It is possible to use some of the components or features from any of the examples in combination with features or components from any of the other examples.

Although the different examples are illustrated as having specific components, the examples of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the embodiments in combination with features or components from any of the other embodiments.