Patent Publication Number: US-9850809-B2

Title: Inlet swirl control for turbochargers

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 13/471,333, filed on May 14, 2012, entitled “INLET SWIRL CONTROL FOR TURBOCHARGERS,” now U.S. Pat. No. 8,579,585, which is a continuation of U.S. patent Ser. No. 12/427,093, filed on Apr. 21, 2009, entitled “INLET SWIRL CONTROL FOR TURBOCHARGERS,” now U.S. Pat. No. 8,177,498, the entire contents of each of which are hereby incorporated by reference for all purposes. 
    
    
     BACKGROUND AND SUMMARY 
     Turbochargers, and superchargers, may be used with internal combustion engines to increase the mass of air entering the combustion chamber of the engine to create more power. An inlet compressor in the form of, for example, a radial fan pump may be disposed in an inlet duct to compress inlet air. In some cases the inlet compressor may be driven by the energy of the exhaust gases of the engine. 
     Airflow characteristics at an inlet compressor inlet may affect turbo inlet efficiency and reduce turbulence related noise by providing additional margin to the compressor surge line. Specifically, the direction of swirl relative to the compressor rotation direction can affect both efficiency and noise. If the swirl direction is opposite from the compressor, turbulence and noise can result, sometimes referred to as tip-in whoosh. Inducing a swirl in the same direction as the compressor can result in improved inlet efficiency (higher mass flow rate) and reduced noise generation. 
     U.S. Pat. No. 7,322,191 discloses a device for imparting a whirling motion on the flow of air for supplying a turbo-supercharged internal-combustion engine. The device is designed to be interposed upstream from the elbow of an elbow-shaped duct. The duct supplies air to the supercharger. The duct has an upstream branch having a square, or rectangular, cross-section, and a downstream branch having a circular section to facilitate formation of a helical flow through the downstream branch. A vane is mounted oscillating about an axis in the upstream branch. In this way, the downstream branch of the elbow portion is reached by a tangential flow that gives rise to the helical flow of the air in the downstream branch. A maximum effect in the generation of the whirling movement is obtained when the vane is at maximum inclination. 
     The inventors herein have recognized issues relating to this approach. As one example, the approach causes the greatest resistance to flow through the duct to achieve maximum effect in the generation of the whirling movement. 
     To address the above issues, a duct with highly engineered geometry, potentially via computational fluid dynamics (CFD) or physical test methods, for directing an inlet flow into an inlet compressor of an internal combustion engine may be provided. The inlet duct may include one or more relief features disposed on an inner surface of the inlet duct. The one or more relief features may be disposed to protrude into the inlet flow to cause the inlet flow to swirl before reaching the inlet compressor. In one example, the one or more relief features may be made integral with the inlet duct. Various example embodiments may provide the required swirl ratios with minimal added restriction, cost, manufacturing, and assembly limitations. 
     Various embodiments may provide elements such as relief features, internal vanes, and/or rifling to compressor inlet ducts to rotate, or swirl an inlet flow before impacting a compressor. The relief features may be formed on an inside surface of the inlet duct by forming troughs in the outside surface. The elements may tune both the direction and magnitude of rotation. The one or more of vanes, rifling, or troughs may be added to the induction system via a variety of methods including, but not limited to, blow molded, injection molded, cast, or hydro-formed metal ducts. In one example, the rifling protrusions from the exterior of the inlet ducts form a screw-shaped pattern to impart rotational flow about the central axis of the duct, the screw-shaped pattern rotating along the length of the duct toward the turbocharger with a rotational direction that is the same as the rotational direction of the compressor. 
     Various embodiments may be “tuned” during the development process. In this way, an optimal swirl ratio with minimal pressure drop may be achieved. 
     Various examples may be utilized on both gasoline, and diesel turbocharged engines. Various examples may be applied to turbocharged, and/or supercharged, engines for the purposes of inlet efficiency and noise control. Embodiments may be used in various applications including, without limitation, automotive applications, military applications, marine applications, aeronautic applications, and off-road usage. 
     It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a schematic depiction of a system illustrating a single cylinder of an engine having a turbo-charging compression device, and features to improve the functionality of, and/or to reduce noise associated with, the compression device. 
         FIG. 2A  shows a schematic depiction of a system including an internal combustion engine showing an example four cylinders, a turbo-charging compression device, and features to improve the functionality of, and/or to reduce noise associated with, the compression device. 
         FIGS. 2B and 2C  are cross-sectional views taken at lines  2 B- 2 B and  2 C- 2 C respectively in  FIG. 2A . 
         FIG. 3A  is a perspective view of an example inlet duct that may be used to direct an inlet flow to a compressor, such as, for example, the compressor illustrated in  FIG. 1 or 2A . 
         FIG. 3B  is a cross-sectional view taken at the line  3 B- 3 B in  FIG. 3A . 
         FIG. 4  is a perspective view of another example inlet duct that may be used to direct an inlet flow to a compressor, such as, for example, the compressor illustrated in  FIG. 1 or 2A . 
         FIG. 5A  is a perspective view of another example inlet duct that may be used to direct an inlet flow to a compressor, such as, for example, the compressor illustrated in  FIG. 1 or 2A . 
         FIG. 5B  is an end view of the example inlet duct shown in  FIG. 5A , as viewed from a direction shown with arrow  5 B in  FIG. 5A . 
         FIG. 5C  is a cross-sectional view taken at the line  5 C- 5 C in  FIG. 5B . 
     
    
    
       FIGS. 3-5  are drawn to scale, although the relative dimensions may be varied from those illustrated, if desired. 
     DETAILED DESCRIPTION 
       FIG. 1  is a schematic diagram showing one cylinder of multi-cylinder engine  10 , which may be included in a propulsion system of an automobile. Engine  10  may be controlled at least partially by a control system including controller  12 , and by input from a vehicle operator  132  via an input device  130 . In this example, input device  130  includes an accelerator pedal and a pedal position sensor  134  for generating a proportional pedal position signal PP. Combustion chamber (i.e., cylinder)  30  of engine  10  may include combustion chamber walls  32  with piston  36  positioned therein. Piston  36  may be coupled to crankshaft  40  so that reciprocating motion of the piston is translated into rotational motion of the crankshaft. Crankshaft  40  may be coupled to at least one drive wheel of a vehicle via an intermediate transmission system. Further, a starter motor may be coupled to crankshaft  40  via a flywheel to enable a starting operation of engine  10 . 
     Combustion chamber  30  may receive intake air from intake manifold  44  via intake passage  42  and may exhaust combustion gases via exhaust passage  48 . Intake manifold  44  and exhaust passage  48  can selectively communicate with combustion chamber  30  via respective intake valve  52  and exhaust valve  54 . In some embodiments, combustion chamber  30  may include two or more intake valves and/or two or more exhaust valves. 
     In this example, intake valve  52  and exhaust valves  54  may be controlled by cam actuation via respective cam actuation systems  51  and  53 . Cam actuation systems  51  and  53  may each include one or more cams and may utilize one or more of cam profile switching (CPS), variable cam timing (VCT), variable valve timing (VVT) and/or variable valve lift (VVL) systems that may be operated by controller  12  to vary valve operation. The position of intake valve  52  and exhaust valve  54  may be determined by position sensors  55  and  57 , respectively. In alternative embodiments, intake valve  52  and/or exhaust valve  54  may be controlled by electric valve actuation. For example, cylinder  30  may alternatively include an intake valve controlled via electric valve actuation and an exhaust valve controlled via cam actuation including CPS and/or VCT systems. 
     Fuel injector  66  is shown coupled directly to combustion chamber  30  for injecting fuel directly therein in proportion to the pulse width of signal FPW received from controller  12  via electronic driver  68 . In this manner, fuel injector  66  provides what is known as direct injection of fuel into combustion chamber  30 . The fuel injector may be mounted in the side of the combustion chamber or in the top of the combustion chamber, for example. Fuel may be delivered to fuel injector  66  by a fuel system (not shown) including a fuel tank, a fuel pump, and a fuel rail. In some embodiments, combustion chamber  30  may alternatively or additionally include a fuel injector arranged in intake passage  44  in a configuration that provides what is known as port injection of fuel into the intake port upstream of combustion chamber  30 . 
     Intake passage  42  may include a throttle  62  having a throttle plate  64 . In this particular example, the position of throttle plate  64  may be varied by controller  12  via a signal provided to an electric motor or actuator included with throttle  62 , a configuration that is commonly referred to as electronic throttle control (ETC). In this manner, throttle  62  may be operated to vary the intake air provided to combustion chamber  30  among other engine cylinders. The position of throttle plate  64  may be provided to controller  12  by throttle position signal TP. Intake passage  42  may include a mass air flow sensor  120  and a manifold air pressure sensor  122  for providing respective signals MAF and MAP to controller  12 . 
     Ignition system  88  can provide an ignition spark to combustion chamber  30  via spark plug  92  in response to spark advance signal SA from controller  12 , under select operating modes. Though spark ignition components are shown, in some embodiments, combustion chamber  30  or one or more other combustion chambers of engine  10  may be operated in a compression ignition mode, with or without an ignition spark. 
     Exhaust gas sensor  126  is shown coupled to exhaust passage  48  upstream of emission control device  70 . Sensor  126  may be any suitable sensor for providing an indication of exhaust gas air/fuel ratio such as a linear oxygen sensor or UEGO (universal or wide-range exhaust gas oxygen), a two-state oxygen sensor or EGO, a HEGO (heated EGO), a NOx, HC, or CO sensor. Emission control device  70  is shown arranged along exhaust passage  48  downstream of exhaust gas sensor  126 . Device  70  may be a three way catalyst (TWC), NOx trap, various other emission control devices, or combinations thereof. In some embodiments, during operation of engine  10 , emission control device  70  may be periodically reset by operating at least one cylinder of the engine within a particular air/fuel ratio. 
     Controller  12  is shown in  FIG. 1  as a microcomputer, including microprocessor unit  102 , input/output ports  104 , an electronic storage medium for executable programs and calibration values shown as read only memory chip  106  in this particular example, random access memory  108 , keep alive memory  110 , and a data bus. Controller  12  may receive various signals from sensors coupled to engine  10 , in addition to those signals previously discussed, including measurement of inducted mass air flow (MAF) from mass air flow sensor  120 ; engine coolant temperature (ECT) from temperature sensor  112  coupled to cooling sleeve  114 ; a profile ignition pickup signal (PIP) from Hall effect sensor  118  (or other type) coupled to crankshaft  40 ; throttle position (TP) from a throttle position sensor; and absolute manifold pressure signal, MAP, from sensor  122 . Engine speed signal, RPM, may be generated by controller  12  from signal PIP. Manifold pressure signal MAP from a manifold pressure sensor may be used to provide an indication of vacuum, or pressure, in the intake manifold. Note that various combinations of the above sensors may be used, such as a MAF sensor without a MAP sensor, or vice versa. During stoichiometric operation, the MAP sensor can give an indication of engine torque. Further, this sensor, along with the detected engine speed, can provide an estimate of charge (including air) inducted into the cylinder. In one example, sensor  118 , which is also used as an engine speed sensor, may produce a predetermined number of equally spaced pulses every revolution of the crankshaft. In some examples, storage medium read-only memory  106  may be programmed with computer readable data representing instructions executable by processor  102  for performing the methods described below as well as other variants that are anticipated but not specifically listed. 
     Engine  10  may further include a compression device such as a turbocharger or supercharger including at least a compressor  162  arranged along intake manifold  44 . For a turbocharger, compressor  162  may be at least partially driven by a turbine  164 , via, for example a shaft  166 . The turbine  164  may be arranged along exhaust passage  48 . For a supercharger, compressor  162  may be at least partially driven by the engine and/or an electric machine, and may not include a turbine. Thus, the amount of compression provided to one or more cylinders of the engine via a turbocharger or supercharger may be varied by controller  12 . 
     As described above,  FIG. 1  shows only one cylinder of a multi-cylinder engine, and that each cylinder may similarly include its own set of intake/exhaust valves, fuel injector, spark plug, etc. 
       FIG. 2A  is a schematic view illustrating an example engine configuration showing four cylinders, and including many features similar to the example illustrated in  FIG. 1 . The figures also illustrate some example differences that may be possible in accordance with present disclosure. For example,  FIG. 1  illustrates throttle  62  located downstream from the compressor  162 , while  FIG. 2A  illustrates throttle  62  located upstream from the compressor  162 . 
     Referring now to  FIG. 1  and to  FIG. 2A , wherein as illustrated, an inlet duct  202  may be shaped to direct an inlet flow  204  into an inlet compressor  162  coupled to the internal combustion engine  10 . The inlet duct  202  may include one or more relief features  206  on an inner surface  208  thereof. The one or more relief features  206  may be made integral with the compressor inlet duct  202 , or otherwise coupled to the compressor inlet duct  202 . The one or more relief features  206  may be disposed to protrude into the inlet flow  204  to cause the inlet flow  204  to swirl, or be given a pre-whirl, before reaching the inlet compressor  162 . As a result, the surge margin may be improved which may result in noise reduction. In this way, the noise from the compressor  162  may be reduced. For example, noise from a so called “tip-in whoosh” may be reduced. Also, or in some cases instead, mass flow into the compressor may be increased which may result in a more ideal operating point within the compressor map thereby improving thermodynamic efficiency. 
     The one or more relief features  206  may be fluid directing means. The fluid directing means may be, for example, elongate ridges extending into a path, or inlet flow  204 , of the induction fluid.  FIGS. 2B and 2C  are cross-sectional views taken at lines  2 B- 2 B and  2 C- 2 C respectively in  FIG. 2A .  FIG. 2B  illustrates the elongate ridges extending into the path of the inlet flow at a first circumferential location  215 , and  FIG. 2C  illustrates the elongate ridges extending into the path of the inlet flow at a second circumferential location  216 , downstream of the first circumferential location  215 . In this example as the elongate ridges extend through the inlet duct  202  from an upstream position shown in  FIG. 2B , to a downstream position shown in  FIG. 2C , the circumferential position has changed. In this example, the circumferential position of each of the elongate ridges has rotated in a counterclockwise direction as the elongate ridges extend longitudinally in the direction of the flow  204 , where the compressor also rotates in a counterclockwise direction. 
     In some examples, the inlet compressor  162  may spin in a first direction  218 , and the relief features may be elongate ridges that extend in a spiral fashion along the inner surface  208  of the inlet duct  202 . The elongate ridges may have a circumferential component and a longitudinal component as described. The circumferential component may be in the first direction, e.g. in the same direction as the spin direction of the inlet compressor. The relief features may then cause the inlet flow to swirl in the first direction  220 . 
     The relief features  206  may be formed from recesses, or troughs  210 , formed on an outside surface  212  of the inlet duct  202 . As stated, in some examples, the relief features  206  may be made integrally with inlet duct. In some examples the inlet duct  202  may be formed using at least one of an injection molding operation, and a blow molding operation. In this way costs may be contained while advantageous functionality may also be achieved. Also, in this way, the structural integrity of the combination of inlet duct  202  with features in accordance with the present disclosure, for example features to reduce noise, may be increased in that they may not move relative to one another. Further, the rigidity and/or stiffness of the ducts themselves may be increased, thus enabling thinner walled, lower weight, inlet ducts. 
     In some examples, the number of relief features  206 , for example, the number of elongate ridges, provided may be three. The inventors herein have recognized that using three elongate ridges may be particularly effective to provide a negative swirl of particular advantage, while still avoiding significant pressure drop. For example, in some examples, the inventors have been able to achieve a negative pre-whirl of approximately 1.05% while only causing a pressure drop of approximately 0.5 kpa. Thus, while in some examples more or less ridges may be used, in the particular example illustrated herein with three ridges, where the angle/pitch of the ridges is as shown in the figures, the unexpected result is achieved that substantially the desired amount of flow rotation is achieved, while minimally impacting flow resistance, as compared with two or four ridges, and/or ridges at other angles/pitches. 
     Other features, and numbered elements, illustrated in  FIGS. 1 and 2 , will be made apparent from the following discussion, and the other figures included in the present disclosure. 
       FIG. 3A  is a perspective view illustrating another example inlet duct  302  according to the current disclosure. This example illustrates one or more, for example three, recessed features located on an outside surface  312  of the inlet duct  302 . The recessed features may extend into the inlet duct  302 , thereby forming one or more relief features  306  located on the inside of the inlet duct  302 . The one or more relief features  306  may include three elongate ridges formed from three elongate troughs  310  formed on the outside surface  312  of the inlet duct  302 . The three ridges may be substantially parallel to one another, and may be arranged at an angle  314  with a plane  316  normal to a central axis  318  of the inlet duct  302 . 
       FIG. 3B  is a cross-sectional view taken at the line  3 B- 3 B in  FIG. 3A . As mentioned, forming the troughs  310  may be equivalent to forming the relief features  306 , in this example, the ridges. The relief features  306  may have a relief feature wall thickness  330 , and the inlet duct  302  may have an inlet duct wall thickness  332 . In some examples, the relief feature wall thickness  330  may be approximately equal to the inlet duct wall thickness  332 . In other examples, the relief feature wall thickness  330  may be different from the inlet duct wall thickness  332 . As with some other examples, the inlet duct  302  may be made in a single operation to include the relief features. Example operations may include, but may not be limited to blow molding, injection molding, and the like. 
     Some examples may provide an inlet duct having relief features which protrude into the inlet flow, but that may not include a corresponding recess formed on the outside surface of the inlet duct. In some cases, relief features formed as such may be made integrally with the inlet duct. In other cases the relief features may be added to the inlet duct, with an attachment operation. 
       FIG. 4  is a perspective view illustrating another example inlet duct  402  according to the current disclosure. In this example, one or more relief features  406  may include, for example, three ridges forming substantially helical protrusions  406  along an inner surface  408  of the inlet duct  402 . In some examples, the one or more relief features  406  may be respectively substantially equally spaced on the inner surface  408 . In some examples, the helical protrusions  406  may be formed by providing troughs  410  formed into an outside surface  412  of the inlet duct  402 . The relief features  406  may be made integral with the inlet duct  402 . In some cases the inlet duct  402  may be made in a single operation. The relief features  406  may be made integrally with the inlet duct  402  using various operations, including, but not limited to blow molding, or injection molding. 
     The example illustrated shows the helically arranged protrusions  406  on a curved portion of the inlet duct  402 . In other examples a straight, or significantly straight, portion of an inlet duct may include helically arranged protrusions. In either case the protrusions may, or may not, include corresponding recesses formed in the outside surface of the inlet duct. 
     In some examples, the one or more relief features may form a rifling pattern. The rifling pattern may include, various numbers of protrusions extending into the inlet flow. 
       FIG. 5A  is a perspective view illustrating another example embodiment in accordance with the current disclosure showing a portion of an intake duct  502 , and  FIG. 5B  is an end view of the inlet duct  502  shown in  FIG. 5A , as viewed from a direction shown with arrow  5 B in  FIG. 5A . The inlet duct  502  illustrated may include guide vanes  556  extending from an inside surface  508  of the inlet duct  502 . The guide vanes  556  may protrude only partway inward, for example toward a central axis  518  of the inlet duct  502 , to leave an unobstructed central area  560  in the inlet duct  502 . The unobstructed central area  560  may be located between opposite blade tips  566  of the guide vanes  556 . 
     In some examples, the number of guide vanes  556  may be four. The guide vanes  556  may be substantially equally spaced within the inlet duct  502 . 
     As described earlier, the inlet compressor may spin in a first direction. In some examples, the guide vanes  556  may be arranged in the inlet duct  502  to have a circumferential component and a longitudinal component. The circumferential component may also be in the first direction. The guide vanes may cause the inlet flow to swirl, also, in the first direction. 
     In some examples, the guide vanes  556  may each extend toward the central axis  518  of the inlet duct  502  a predetermined amount  562  relative to a diameter  564  of the inlet duct  502 . The inventors herein have recognized that by providing an unobstructed central area  560  having a particular predetermined size relative to a total cross-sectional area of the inlet duct  502  may be particularly effective to provide a negative pre-whirl of particular advantage, while still avoiding significant pressure drop. For example, in some embodiments, the inventors have been able to achieve a negative pre-whirl of 52.3% while only causing a 1.6 kpa pressure drop. In some examples, the distance between the opposite blade tips  566  may be approximately equal to between one half and three fourths of the diameter  564  of the inlet duct  502 . Included among such examples, the distance between opposite blade tips  566  may be approximately equal to two thirds of the diameter  564  of the inlet duct  502 . In other words, in some cases, the guide vanes  556  may each extend toward the central axis  518  a distance  562  of approximately one sixth of the diameter  564  of the inlet duct  502 . 
     The guide vanes  556  may be included in an inlet duct that may also include fluid directing means that may be the same, or similar to, the relief features described herein. The guide vanes  556 , and the relief features, may be shaped and positioned to work cooperatively to advantageous effect, such as to provide improved pre-swirl, and/or reduced pressure drop. In some examples, the guide vanes  556  may be located upstream from the one or more relief features. In other examples, the guide vanes  556  may be located downstream from the one or more relief features. 
     In some examples, the guide vanes  556  may be used in an inlet duct without the fluid directing, or relief features such as those illustrated herein. Further, in some cases, the relief features discussed herein may be included in an inlet duct without guide vanes such as those illustrated herein. 
     In some cases, the fluid directing, or relief, features may be configured similar to the guide vanes  556  illustrated herein. The guide vanes  556  may be formed integrally with the inlet duct  502 . In addition, the guide vanes  556 , when included with relief features, may both be formed integrally with the inlet duct  502 . Integral formation, of various combinations of the elements described herein may, in some cases, be achieved using a blow molding operation, an injection molding operation, a casting operation, a hydro-forming operation, or the like. 
       FIG. 5C , illustrates a cross-sectional view taken at the line  5 C- 5 C in  FIG. 5B . One or more of the guide vanes  556  may be formed on an inside surface  508  of the inlet duct  502  by forming troughs  510  on an outside surface  512  of the inlet duct  502 . Each guide vane  556  may have opposing walls  528  on either side of the guide vane trough  510 . A trough bottom  534  may close the trough  510 . One or both of the opposing walls  528  may have a trough wall thickness  530 , and the inlet duct may have a duct wall thickness  532 . In some cases, the trough wall thickness  532  may be approximately equal to the duct wall thickness  530 . In other cases, the trough wall thickness  530 , and the duct wall thickness  532 , may be different. 
     In some cases, one or more of the example inlet ducts disclosed herein may be all or part of a primary compressor inlet duct. In some examples, one or more of the example inlet ducts may be used as all of, or part of, or with a primary turbo runner. In addition, or instead, one or more of the example inlet ducts may be used as all of, or part of, a secondary turbo runner. 
     Returning again to  FIGS. 1 and 2 , various example embodiments are illustrated that may include an induction system  100  for use in an internal combustion engine  10 . The induction system  100  may provide an inlet compressor  162  configured to compress an induction fluid, and to pass the induction fluid to a combustion chamber  30 . An inlet duct  202  may be provided for directing the induction fluid toward the inlet compressor  162 . Relief features  206  may be formed as part of the inlet duct  202 . The relief features  206  may be sized and shaped to cause the induction fluid to swirl before reaching the inlet compressor  162 . 
     Also illustrated is an example system  200  for directing an inlet flow toward an inlet compressor  162  for use in an internal combustion engine  10 . The system  200  may include three elongate protrusions  206  integrally formed in relief on an inside surface  208  of an inlet duct  202  by three corresponding troughs  210  formed on an outside surface  212  of the inlet duct  202 . The protrusions  206  may extend into the inlet duct  202  to cause the inlet flow  204  to swirl. The number of geometric features may be application dependent, and may be best defined by CFD analysis in conjunction with dynamometer confirmation. 
     Some other examples may include insertion of scrolls, springs, or a separate vane assembly into an inlet duct. 
     It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein. 
     The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.