Abstract:
An exhaust manifold of a turbocharged engine includes a collar coolant jacket to maintain component temperatures within acceptable limits. The collar coolant jacket is specifically located around the exhaust outlet of the manifold.

Description:
TECHNICAL FIELD 
     The present application relates to exhaust manifold systems and methods of heating engine systems and more particularly to cast exhaust manifolds including a collar coolant jacket. 
     BACKGROUND AND SUMMARY 
     An exhaust manifold of a turbocharged engine is exposed to thermal loads not present in a typical cast iron or stainless steel exhaust manifold of a naturally aspirated engine. One approach to compensate for increased temperature loads and reduce manifold degradation includes a ferritic or austenitic stainless steel cast exhaust manifold. Such steel materials may reduce the thermal expansion of the manifold, increase the thermal insulation of the manifold and protect the manifold from creep degradation, for example. A further approach involves cooling via a coolant jacket encompassing a major portion of the exhaust manifold. 
     The inventors herein have recognized issues with the above described approaches. The inclusion of ferritic or austenitic stainless steel materials in an exhaust manifold may significantly increase manifold cost in comparison to manifolds without such materials. Further, cooling the exhaust manifold via encompassing a majority or more of an exhaust manifold removes thermal energy that would otherwise improve both turbocharger and catalyst function and performance. 
     Accordingly, as a brief summary, devices, systems and methods are disclosed for a coolant jacket included in an exhaust manifold. In one example an exhaust manifold system includes a plurality of inlets to runners extending perpendicular a longitudinal manifold axis, an outlet passage distal from the runners, the outlet passage terminating with a manifold flange, and a coolant jacket including a coolant inlet and outlet both for coupling to a coolant system, and a collar fluidically coupling the coolant inlet and outlet, the collar adjacent the outlet passage and the manifold flange and decoupled from the runners. 
     In a further example a method of heating engine systems, the method includes combusting fuel in a cylinder of an engine, adsorbing heat from combusted fuel exhaust into a coolant via a coolant jacket, the coolant jacket including a collar, the collar only surrounding the circumference of an exhaust passage outlet adjacent an exhaust manifold flange, the outlet asymmetrically positioned at a first manifold end, distal from a plurality of exhaust runners, the outlet passage extending out away from a plane including the totality of runners and the outlet passage extending parallel from the runners away from inlets included in the runners, and the outlet passage terminating with a manifold flange, flowing heated coolant from an outlet of the coolant jacket to a heating circuit, the heating circuit including a heating element for at least one of a cabin heater, a catalyst, an injector, an intake air heater, and a positive crankcase ventilation system, and flowing combusted fuel exhaust to a turbine of a turbocharger, an amount of retained heat of combusted fuel exhaust greater than an amount of coolant adsorbed heat. 
     By including the collar water jacket surrounding the outlet passage, the exhaust manifold system may include lower-cost materials (e.g., a silicon molybdenum) while removing less thermal energy—thermal energy that can be used to increase turbocharger and catalyst performance. Another advantage is that the collar coolant jacket is a heat source (for example during engine warm up) for a heating element, such as in a cabin heater, a catalyst, an injector, an intake air heater, and/or a positive crankcase ventilation system. 
     It will 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, which follows. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined by the claims that follow the detailed description. Further, 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 DRAWINGS 
         FIG. 1  shows an engine including an exhaust manifold system. 
         FIG. 2  shows a first semi-transparent view of an example exhaust manifold including a collar coolant jacket. 
         FIG. 3  shows a second semi-transparent view of the example exhaust manifold of  FIG. 2 . 
         FIG. 4  shows an opaque view of the example exhaust manifold of  FIG. 2 . 
         FIG. 5  shows a first cut-away view of the example exhaust manifold of  FIG. 2 . 
         FIG. 6  shows a second cut-away view of the example exhaust manifold of  FIG. 2 . 
         FIG. 7  shows a third cut-away view of a first end of the example exhaust manifold of  FIG. 2 . 
         FIG. 8  shows a first view of the coolant and exhaust passages of the example manifold of  FIG. 2 . 
         FIG. 9  shows a second view of the coolant and exhaust passages of the example manifold of  FIG. 2 . 
         FIG. 10  illustrates an example method for heating engine systems. 
     
    
    
     DETAILED DESCRIPTION 
     First an engine and related exhaust systems are discussed with reference to  FIG. 1 . Next an example exhaust manifold shown in  FIGS. 2-9  is discussed. Then, an example method for heating engine systems with the exhaust manifold system described in  FIGS. 1-9  is discussed with respect to  FIG. 10 . 
     Turning first to  FIG. 1 , aspects of an example engine  10  are shown. Multi-cylinder engine  10  may be included in a propulsion system of an automobile. In the present example, engine  10  is shown in a V6 configuration, however further examples may include V8, V12, I4, I6, boxer, and additional engine configurations. Engine  10  may be a spark ignition engine or compression ignition engine. 
     Engine  10  may be controlled at least partially by a control system  12  including controller  14  and by input from sensors  16  and/or a vehicle operator  18  via an input device  20 . In this example, input device  20  includes an accelerator pedal and a pedal position sensor  22  for generating a proportional pedal position signal PP. Controller  14  outputs signals and commands to actuators  24  to control the operation of engine  10  and related systems. 
     A plurality of combustion chambers (cylinders)  26  is included in engine  10 , each including combustion chamber walls with a piston positioned therein. Engine  10  includes an engine block  28  coupled to cylinder heads  30 , the combustion chamber walls defined by the engine block  28 , first cylinder head  30 , and second cylinder head  32 . Each piston may be coupled to crankshaft  34  so that reciprocating motion of each piston is translated into rotational motion of the crankshaft. Crankshaft  34  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  34  via a flywheel to enable a starting operation of engine  10 . 
     Each combustion chamber  26  may receive intake air from an intake manifold via an intake passage (not shown) and may exhaust combustion gases via an exhaust manifold  36 . The intake manifold and exhaust manifold  36  can selectively communicate with combustion chambers  26  via respective intake valves and exhaust valves (not shown). In some embodiments, one or more of the combustion chambers  26  may include two or more intake valves and/or two or more exhaust valves. Engine intake valves and engine exhaust valves may be mechanically actuated (e.g., by an over head cam), electro-magnetically actuated (e.g., EVA) or some combination of the two. Further, engine  10  may include port injection or direct injection in one or more of the plurality of combustion chambers  26 . 
     In the present example, exhaust manifold  36  is only coupled to a first cylinder bank of first cylinder head  30 . A second exhaust manifold (e.g., coupled to a second cylinder bank included in second cylinder head  32 ) is not shown for the sake of simplicity. However, a second exhaust manifold in a “V” configuration engine may be provided. Further, in the present example, exhaust manifold  36  is included as part of exhaust manifold system  38  that also includes turbocharger  40 , exhaust aftertreatment system  42 , and coolant system circuit  44 . 
     Furthermore, exhaust manifold  36  includes a cast housing. The housing may include an alloy of iron (e.g., nodular, ductile, etc), carbon, and a number of additives such as Si, Cr, Mo, Ni and Sn. Exhaust manifold  36  includes a plurality of inlets  46  at the end of a plurality of runners  48 , the inlets coupled to the cylinder head  30  via the cylinder head gasket  50 . The plurality of inlets  46  to runners  48  extend perpendicular a longitudinal manifold axis  52 , the longitudinal axis extending in a longitudinal direction along the cylinder head from each combustion chamber  26  in the first cylinder head  30 . 
     Manifold  36  further includes an outlet passage  54  distal from the runners  48 . In the present example, outlet passage  54  is shown reflected across longitudinal axis  52  from the runners  48 . Additionally, the outlet passage  54  terminates with a manifold flange  56 . In the present example, a turbocharger casing flange  41  of turbocharger  40  is coupled to the manifold flange  56  to receive exhaust gas from the exhaust manifold  36 . 
     Manifold  36  further includes a coolant jacket  58 . Included in coolant jacket  58  are a collar  60 , a coolant inlet  62  and a coolant outlet  64 . The collar  60  fluidically couples the coolant inlet  62  and outlet  64  and the collar  60  includes a first flow path  66  and a second flow path  68 , discussed in more detail below with respect to  FIG. 8 . Further, the collar  60  is adjacent the outlet passage  54  and the manifold flange  56 . The collar  60  may be positioned to lessen overall thermal energy transfer between the manifold  36  and the coolant jacket  58 . Further, the collar  60  may increase thermal energy transfer at locations that are vulnerable to high thermal loads (e.g., the manifold flange  56  and outlet passage  54 ). Specifically, the collar  60  is decoupled from (e.g., not directly coupled to, and not adjacent to) the runners  48  and may further be decoupled from the majority of manifold  36  housing surface area. 
     In the present example, exhaust manifold system  38  further includes a coolant system circuit  44 . Both the coolant inlet  62  and coolant outlet  64  of coolant jacket  58  are coupled to the coolant system circuit  44 . In the present example, quick connect tubes  70  couple the inlet  62  and outlet  64  to the coolant system circuit  44 . Each quick connect tube  70  includes an annular elastomeric seal and a snap ring at an end of the tube. The snap ring secures each tube  70  in place via a straight line axial movement of the tube over the outlet  64  or inlet  62  so that the secured tube  70  forms a dynamic seal. 
     The coolant system circuit  44  includes a heating element  72 . Heating element  72  may be included in at least one of a cabin heater, a catalyst, an injector, an intake air heater, and a positive crankcase ventilation system. In further examples, coolant jacket  58  includes a plurality of inlets receiving coolant and/or outlets returning coolant from two or more coolant circuits of a coolant system, including a plurality of heating elements. Coolant system circuit  44  may be coupled to further coolant and heating system components, such as a radiator, heater core, and the like. 
     In the present example, turbocharger  40  is coupled to the exhaust manifold  36  at manifold flange  56 . In additional examples, two exhaust manifolds are each coupled to two turbochargers, one turbocharger coupled to each exhaust manifold (e.g., a twin turbocharger configuration). Further still, turbocharger  40  may be coupled to two exhaust manifolds. Turbocharger  40  includes a compressor (not shown) arranged along the intake passage and which may be at least partially driven by a turbine  74  (e.g., via a shaft) arranged in exhaust passage  76 . The compressor may also be at least partially driven by the engine (e.g., via crankshaft  34 ) and/or an electric machine. Turbocharger  40  includes a bypass passage  78  coupled intermediate the manifold  36  and the turbine  74  as well as intermediate the turbine  74  and exhaust aftertreatment system  42 , a waste gate  80  disposed within the bypass passage  78 . The amount of compression provided to one or more cylinders  26  of the engine via turbocharger  40  may be varied by controller  14  through, for example, control of waste gate  80 . 
     In the present example, exhaust gas that passes through bypass passage  78  or turbine  74  flows to exhaust aftertreatment system  42 . Exhaust aftertreatment system  42  is disposed in exhaust passage  76  and may include a three-way catalyst (TWC), diesel oxidation catalyst, diesel particulate filter (DPF), selective catalytic reduction (SCR) catalyst, or combinations thereof. In the present example, aftertreatment system  42  is shown coupled to the coolant system circuit  44  at  82  and  84 . In further examples, heating element  72  is coupled to, or included in, aftertreatment system  42 . Further examples of engine  10  may include one or both of a low pressure (LP) and a high pressure (HP) exhaust gas recirculation (EGR) loop, along with corresponding valves and sensors. 
       FIGS. 2-9  show scale drawings of an embodiment of an exhaust manifold  200 . Manifold  200  is a sand cast manifold forming a plurality of inlets  202 ,  204  and  206  to runners  208 ,  210 , and  212  an outlet passage  214 , and coolant jacket  216 , and is one example of manifold  36  described above. In the present example there are three runners coupled to three cylinders of an example engine, but in further examples there may be less than or greater than three runners depending on the number of cylinders in the example engine. Also in the present example, manifold  200  includes a silicon molybdenum alloy (e.g., HiSiMo); further examples may include additional and alternative materials. 
       FIG. 2  shows a first view of manifold  200 . Manifold  200  is shown semi-transparent with dotted shading indicating an interior passage  218  defined by an interior of manifold housing  220 . During casting, the interior passage  218  is filled by a main manifold core (discussed in more detail below with respect to  FIGS. 8 and 9 ). Interior passage  218  extends from a first inlet  202  to a last inlet  206  along longitudinal axis  222  (discussed in more detail below with respect to  FIGS. 3-5  and  9 ). Manifold  200  is longer along the longitudinal axis  222  than in a second direction extending away from the example engine. Further manifold  200  is longer along longitudinal axis  222  than in a third direction perpendicular to the longitudinal direction and the second direction. 
     Manifold  200  includes example coolant jacket  216  also defined by the manifold housing  220 . The coolant jacket  216  includes an example collar  224 , fluidically coupling a coolant inlet  226  and outlet  228 . Coolant outlet  228  extends parallel the longitudinal axis  222 . The collar  224  is adjacent outlet passage  214 , the outlet passage  214  shown as a section of the interior passage  218  leading to an example turbocharger (discussed in more detail above with respect to  FIG. 1 ). The collar  220  is also adjacent example manifold flange  230  (which includes a plurality of flange bolt eyelets, described in more detail below with respect to  FIG. 3 ). In the present example, collar  224  includes a longitudinal section  232  of the jacket  216  extending parallel the longitudinal axis  222 . The longitudinal section  232  is directly coupled, via casting, to the collar  224  and the coolant inlet  226 . 
     Additionally, the position of the collar  224  is decoupled from the runners  208 ,  210  (shown in  FIG. 4) and 212 . Because the coolant jacket  216  is not adjacent to any of the runners, exhaust gases flowing from the inlets through the exhaust manifold  200  retain more thermal energy than exhaust in a manifold including an encompassing coolant jacket. In this way, the amount of thermal energy sent to the example turbocharger coupled to the exhaust manifold  200  is increased. Further, because manifold  200  includes coolant jacket  216 , thermal stress to the adjacent manifold flange  230  and outlet passage  214  is reduced. Consequently, exhaust manifold housing  220  may be made of a material other than ferritic or austenitic steel. 
     Additionally, in the present example, the exhaust manifold housing  220  includes a plurality of engine bolt eyelets  234  (which may or may not be threaded) for coupling the manifold  200  to the example engine via an example cylinder head gasket (as described in more detail above, with respect to  FIG. 1 ). 
     Turning next to  FIG. 3 , a second semi-transparent view of exhaust manifold  200 , and more particularly a first end  236 , is shown. In the present example, outlet passage  214  terminates at manifold flange  230 . Manifold flange  230  includes a plurality of flange bolt eyelets  241 . Furthermore, in the present example, longitudinal section  232  is not penetrated or interrupted by any of the flange bolt eyelets  241 . 
     In the present example, both the collar  224  and a manifold flange face  240  are in a first plane and the coolant inlet  226  and coolant outlet  228  extending out in a second plane not parallel to the first plane. In further examples, the coolant inlet  226 , coolant outlet  228 , collar  224  and flange face  240  all lie in planes parallel to each other. In additional examples, a plane parallel to the directions in which coolant inlet  226  and coolant outlet  228  extend is skew to a plane including at least one of the collar  224  and a manifold flange face  240 . 
     A third plane  242  is perpendicular to the view of  FIG. 3 . In the present example, longitudinal axis, shown at  222  in  FIGS. 1-2 ,  4 - 5 ,  7  and  9 , lies in plane  242 . Further, plane  242  is defined as a plane that intersects the totality of the runners, (of which, runner  208  and runner  212  are shown in  FIG. 3 ). 
     Outlet passage  214  is shown distal from the runners and is asymmetrically positioned at the first end  236 . The first end  236  is extended down the longitudinal axis, opposite from the second end  238  of the manifold. Further, the outlet passage  214  extends out away from the plane  242 , in an upward direction indicated at arrow  244 . The upward direction indicated at  244  is opposite the direction coolant inlet  226  extends. Additionally, outlet passage  214  extends in a direction, indicated at arrow  246 , away from the inlets (for example, inlet  206 ) and parallel with the runners (for example, runner  212 ). Further, collar  224  and coolant outlet  228  are positioned above the plane  242 . 
     Turning next to  FIG. 4 , manifold  200  is shown in an opaque view looking towards inlets  202 ,  204  and  206  away from where an example engine would couple to manifold  200 . Plane  242  cuts across the current view and, as discussed above, the plurality of inlets  202 ,  204  and  206  to runners  208 ,  210  and  212 , included in plane  242 , extend out away the viewer into the page. The plurality of engine bolt eyelets  234  are arranged around the plurality of inlets  202 ,  204  and  206  to distribute a bolt load when the runners  208 ,  210  and  212  are coupled to an example cylinder head gasket. Further,  FIG. 4  shows the coolant inlet  226  extending in a direction perpendicular to the plane  242 . As discussed above (with respect to  FIG. 3 ) coolant outlet  228  is positioned vertically above plane  242 . Similarly outlet passage  214  extends above plane  242 . 
       FIG. 5  is a first cut away view of exhaust manifold  200 , looking towards where an example engine would be positioned. Inlets  202 ,  204  and  206  are shown leading to interior passage  218 . In the present example, manifold housing  220  defines the interior passage  218  which includes a bend  248 . In the present example, bend  248  does not extend in the direction of the longitudinal axis beyond inlet  204 . The bend  248  continues in the opposite direction toward inlet  206 . Turning quickly to  FIG. 6 , exhaust manifold  200  is shown in a second cut away view, looking away from a position of an example engine.  FIG. 6  also shows bend  248  formed in interior passage  218 , defined by housing  220 . Bend  248  extends further along longitudinal axis  222  than coolant inlet  226  or longitudinal section  232  in a direction away from outlet passage  214 . Further, bend  248  is included in the present example to improve and enable the combination of flow from the first inlet  202 , second inlet  204  and third inlet  206 . Additionally bend  248  is included in the present example to improve and enable the direction of flow toward outlet passage  214  (as described elsewhere, for example with respect to  FIGS. 2-4 ). 
     Returning to  FIG. 5 , coolant outlet  228  is shown extending out parallel to the longitudinal axis  222  of the manifold. Further, coolant inlet  226  extends downward substantially perpendicular to both the runners and the coolant outlet  228 . Further, collar  224  includes diverter rib  250 . Diverter rib  250  is defined by the shape of housing  220  on an interior of the coolant jacket  216  and on a circumference of the outlet passage  214 . 
     Returning to  FIG. 6 , the diverter rib  250  included in collar  224  is shown in relation to the coolant outlet  228  and the outlet passage  214 . Further, diverter rib  250  extends into an interior of the coolant jacket collar  224 . In the present example, the inclusion of diverter rib into manifold  200  creates more surface area over which coolant inside coolant jacket  216  may flow, thus increasing heat transfer efficiency between the outlet passage  214  and the coolant jacket  216 . Further, the diverter rib  250  extends toward the coolant outlet  228 , and is positioned where an example first flow path  254  and an example second flow path  256  meet. The positioning of the diverter rib  250  in the present example may direct flow of coolant from each of the flow paths  252  and  254 , so that when the first and second flow paths  252  and  254  combine, an amount of turbulence in coolant flow is decreased. 
     Turning now to  FIG. 7 , a further cut away view of exhaust manifold  200  at the first end  236  is shown. Longitudinal section  232  includes a longitudinal flow path  256  in the present example. The longitudinal flow path  256  directs coolant flow from the coolant inlet  226  to collar  224 . Collar  224  splits the longitudinal flow path  256  into only first flow path  254  and second flow path  256  defined. The two flow paths  254  and  256  collectively surrounding the circumference of the outlet passage  214 . Further, coolant within the collar  224  thermally communicates with the outlet passage  214  via the housing  220  (e.g., a cast metal wall). 
     The first flow path  254  includes a first collar profile and the second flow path  256  includes a second collar profile. In the present example, each collar profile is the shape of the interior of the collar, which is important in defining coolant flow direction, velocity and pressure, in each flow path respectively. Further, in the present example collar  224  has a smooth surfaced interior. Additionally, each flow path may define a cross-sectional area through which coolant may flow. In some examples the cross-sectional area may be perpendicular to a direction of flow. What is more, the coolant inlet  226  has an inlet profile and in the present example, the cross-sectional areas of both the first and second collar profiles are less than a cross-sectional area of the coolant inlet profile. In further examples, only one of the first and second collar profiles has a cross-sectional area less than the cross-sectional area of the coolant inlet profile. 
     Next,  FIG. 8  shows a first view of the exhaust and coolant passages of exhaust manifold  200 . Interior passage  218 , outlet passage  214  and coolant jacket  216  are shown without an example manifold housing (described above with respect to  FIGS. 2-7 ). In one example, interior passage  218  and outlet passage  214  define a main exhaust core, and coolant jacket  216  defines a coolant core. Both the main exhaust core and coolant core are casting cores in such an example. These casting cores are positioned as shown and would be placed together into an exterior mold during a casting process. Metal poured into the mold may then take the shape of the molds, hardening and forming the housing of example manifold  200 . Such a casting process is well known in the art. 
       FIG. 9  shows a second view of the exhaust passages and coolant passages of manifold  200  looking downward toward to a top of interior passage  218  and coolant jacket  216 . Outlet passage  214  is shown distal from the runners and asymmetrically positioned at first end  236  of manifold  200 . Outlet passage  214  is reflected across longitudinal axis  222  from runners,  208 ,  210  and  212 . In this way outlet passage  214  may be distal from the runners. In the present example runner  210  is approximately a longitudinal middle of the manifold  200 , and the first manifold end  236  is a region of the manifold extending from runner  210  toward runner  212  along the longitudinal axis  222  and second manifold end  238  is a region extending along manifold  200  in an opposite direction. In this way the outlet passage  214  may be asymmetrically positioned. 
     Further, one example of how far longitudinal section  232  extends parallel to longitudinal axis  222  is shown in  FIG. 9 . In the present example, a length of longitudinal section  232  is less than a distance between successive exhaust runners (e.g., runners  210  and  212 ). Furthermore, in general, a length of the longitudinal section  232  may be equal to, or less than, half the longitudinal length of the interior passage  218 . 
     Finally, turning to  FIG. 10 , an example method  1000  for heating engine systems is illustrated. In the present example, method  1000  may include the use of an example control system and/or exhaust manifold system including an example exhaust manifold with collar coolant jacket, example turbocharger, example exhaust aftertreatment system, and example coolant system circuit. 
     Example method  1000  starts to  1010  by combusting fuel in a cylinder of an engine. After fuel has been combusted in a cylinder of the engine, the exhaust gases may be vented from the cylinder to an example exhaust manifold with coolant jacket, the coolant jacket including a collar. As hot exhaust gases enter the manifold, the method may optionally include at  1012 , flowing coolant through a coolant inlet fluidically coupled to the collar. 
     After  1012 , the method may optionally continue to  1014  which includes splitting coolant flow into a first flow path and a second flow path in the collar, the first flow path including a first collar profile, the second flow path including a second collar profile and the coolant inlet having an inlet profile, a cross-sectional area of at least one of the first and second collar profiles less than a cross-sectional area of the inlet profile. Further, the collar may include only the first and second flow paths and the collar may include a smooth interior surface to encourage laminar flow. The interior of the collar defines the flow paths and the flow paths collectively surround a circumference of an example outlet passage. 
     Next, the method includes adsorbing heat from combusted fuel exhaust into a coolant via the coolant jacket, the coolant jacket including the collar, the collar only surrounding the circumference of an exhaust outlet passage adjacent a manifold flange, the outlet passage terminating with the manifold flange at  1016 . Furthermore, the outlet passage may be asymmetrically positioned at a first manifold end, distal from a plurality of exhaust runners. Additionally, the outlet passage extends in two directions. First, the outlet passage extends out away from a plane including the totality of runners. Second, the outlet passage extends parallel from the runners, away from inlets included in the runners. 
     Next, method  1000  optionally includes recombining heated coolant of the first and second flow paths within the collar while flowing the heated coolant to the coolant outlet at  1018 . It should be appreciates recombining heated coolant at  1018  may only be included in examples method  1000  that further include processes that split coolant flow into two or more flow paths (e.g., as at  1014 ). 
     After either completing  1016  or  1018 , the method continues to  1020  which includes flowing heated coolant from an outlet of the coolant jacket to a heating circuit, the heating circuit including a heating element for at least one of a cabin heater, a catalyst, an injector, an intake air heater, and a positive crankcase ventilation system. The method may then continue to  1022  to flow combusted fuel exhaust to a turbine of a turbocharger, an amount of retained heat of combusted fuel exhaust greater than an amount of coolant adsorbed heat. After  1022 , the method  1000  may end. 
     Finally, it will be understood that the articles, systems and methods described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are contemplated. Accordingly, the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and methods disclosed herein, as well as any and all equivalents thereof.