Patent Publication Number: US-8978705-B2

Title: Apparatus for reducing turbulence in a fluid stream

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 12/478,015, filed on Jun. 4, 2009, entitled “Apparatus For Reducing Turbulence In A Fluid Stream”, the disclosure of which is incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND 
     The disclosure relates generally to apparatus for reducing turbulence in a fluid stream and damping pressure pulsations propagated by the fluid. More particularly, the disclosure relates to a flow straightening device that reduces turbulence in moving fluid. Still more particularly, it relates to a flow straightener that reduces turbulence of drilling fluid passing through a mud pump and that dampens pressure pulsations propagated by the drilling fluid. 
     To form an oil or gas well, a bottom hole assembly (BHA), including a drill bit, is coupled to a length of drill pipe to form a drill string. Instrumentation for performing various downhole measurements and communication devices are commonly mounted within the drill string. The drill string is then inserted downhole, where drilling commences. During drilling, fluid, or “drilling mud,” is circulated down through the drill string to lubricate and cool the drill bit as well as to provide a vehicle for removal of drill cuttings from the borehole. 
     Mud pumps are commonly used to deliver drilling mud to the drill string during drilling operations. Many conventional mud pumps include a piston-cylinder assembly hydraulically coupled to a compression chamber disposed between a suction module and a discharge module. The suction module is coupled to a suction manifold through which drilling mud is supplied to the mud pump, and the discharge module is coupled to a discharge manifold into which pressurized drilling mud is exhausted from the mud pump. The suction module includes a valve which is operable to allow or prevent the flow of drilling mud from the suction manifold into the compression chamber. Similarly, the discharge module includes a valve which is operable to allow or prevent the flow of pressurized drilling mud from the compression chamber into the discharge manifold. Each valve has a closure member or poppet that is urged into sealing engagement with a sealing member or seat by a biasing member, such as a spring. 
     During operation of the mud pump, the piston reciprocates within its associated cylinder. As the piston moves to expand the volume within the cylinder, the discharge valve closes, and suction valve opens. Drilling mud is drawn from the suction manifold through the suction valve into the compression chamber. When the piston reverses direction, decreasing the volume within the cylinder and increasing the pressure of drilling mud contained with the compression chamber, the suction valve closes, and the discharge valve opens to allow pressurized drilling mud from the compression chamber into the discharge manifold. While the mud pump is operational, this cycle repeats, often at a high cyclic rate, and pressurized drilling mud is continuously fed to the drill string. 
     Due to the reciprocating motion of the mud pump piston, cyclic loads are transferred to the suction module by virtue of its coupling to the mud pump. The transferred loads cause cyclic deformation of the suction module. Consequently, pressure pulsations are created within and propagated by the drilling mud passing therethrough. 
     Additionally, because the suction module typically includes piping elbows, bends, and “Ts,” drilling mud flowing from the suction manifold into the suction module, upstream of the suction valve, is often highly turbulent. When the suction valve opens, the turbulent drilling mud flows rapidly into the compression chamber. Due to the turbulent nature of the drilling fluid, bubbles form within the compression chamber as the drilling fluid flows rapidly around the suction valve poppet. When the piston subsequently compresses the drilling mud within the compression chamber, these bubbles burst, creating additional pressure pulsations within the drilling mud. 
     The formation of bubbles within the compression chamber due to the turbulent nature of drilling mud passing around the suction valve poppet reduces the efficiency of the mud pump. Moreover, pressure pulsations created within and carried by the drilling mud disturb downhole communication devices and instrumentation, and potentially degrade the accuracy of measurements taken by the instrumentation. Over time, the pressure pulsations may also cause fatigue damage to the drill string pipe. 
     Accordingly, there is a need for apparatus that reduces turbulence within drilling mud systems and that dampens pressure pulsations caused by the reciprocating motion of mud pumps coupled thereto. 
     SUMMARY OF THE DISCLOSURE 
     A flow straightener includes a conduit segment and a plurality of elongate vanes. The conduit segment has an inner surface and an interior volume for conveying the fluid in a predetermined direction of flow. The elongate vanes are disposed within the interior volume. Each of the vanes has a radially innermost edge and a radially outermost edge. The innermost edges of the vanes are spaced apart from one another so as to provide a core portion of the interior volume that is generally free of obstruction. 
     In some embodiments, the flow straightener includes the conduit section and a plurality of pins that support the vanes within the interior volume. The pins are flexibly coupled to the inner surface of the conduit segment. Likewise, in certain embodiments, the flexible coupling includes an elastomeric insert having tapered sides that engage correspondingly tapered sides of a recess formed in the conduit section. The cross-sectional shape of the pins may be noncircular in various embodiments. 
     Thus, embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, and by referring to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a detailed description of the disclosed embodiments, reference will now be made to the accompanying drawings in which: 
         FIG. 1  is a cross-sectional view of a drilling fluid system including a fluid flow straightener in accordance with the principles disclosed herein; 
         FIG. 2  is a perspective view of the flow straightener of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of the flow straightener of  FIG. 2 ; 
         FIG. 4  is a perspective view of an insert of the flow straightener of  FIG. 2 ; 
         FIG. 5  is a perspective view of a vane-supporting pin of the flow straightener of  FIG. 2 ; 
         FIG. 6  is a perspective view of a vane of the flow straightener of  FIG. 2  supported by the pin of  FIG. 5 ; 
         FIGS. 7A and 7B  are perspective views of the flow straightener of  FIG. 2  as viewed generally from the downstream and upstream directions, respectively; 
         FIGS. 8A and 8B  are perspective and side views, respectively, of the flow straightener of  FIG. 2 ; and 
         FIGS. 9A and 9B  are an end view and an enlarged portion of the end view, respectively, of the flow straightener of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS 
     The following description is directed to an exemplary embodiment of a drilling fluid system including a fluid flow straightener. The embodiment disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. One skilled in the art will understand that the following description has broad application, and that the discussion is meant only to be exemplary of the described embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment. For example, the apparatus described herein may be employed in any fluid conveyance system where it is desirable to reduce the turbulence of fluid contained within or moving through the system. 
     Certain terms are used throughout the following description and the claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features and components described herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in interest of clarity and conciseness. 
     In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. Further, the terms “axial” and “axially” generally mean along or parallel to a central or longitudinal axis. The terms “radial” and “radially” generally mean perpendicular to the central or longitudinal axis, while the terms “azimuth” and “azimuthally” generally mean perpendicular to both the central or longitudinal axis and a radial axis normal to the central longitudinal axis. As used herein, these terms are consistent with their commonly understood meanings with regard to a cylindrical coordinate system. 
     Referring now to  FIG. 1 , there is shown a drilling fluid system  100  configured to pressurize drilling fluid, or drilling mud. Drilling fluid system  100  includes a pump assembly  105  coupled between a suction manifold  110  and a discharge manifold  115 . Suction manifold  110  is coupled to a fluid source (not shown), for example, a storage tank commonly found at many drilling sites. Discharge manifold  115  is coupled to a fluid destination (not shown), such as but not limited to a drill string. A flow straightener  200  in accordance with the principles disclosed herein and a flexible connection  195  are coupled between suction manifold  110  and pump assembly  105 . 
     Pump assembly  105  includes a pump  125  and a valve assembly  120 . Pump  125  is a reciprocating pump, having a piston  185  slidingly disposed within a cylinder  190 . Valve assembly  120  includes a suction module  130 , a discharge module  135 , and a fluid conduit or compression chamber  140  disposed therebetween. Pump  125 , suction manifold  110 , and discharge manifold  115  are each hydraulically or fluidicly coupled to compression chamber  140 . Suction module  130  includes a valve  145  that is operable to allow or prevent the flow of fluid from suction manifold  110  into compression chamber  140 . Suction valve  145  has a closure member or poppet  155  that is urged into sealing engagement with a sealing member or seat  160  by a biasing member  165 , such as a spring. Similarly, discharge module  135  includes a valve  150  that is operable to allow or prevent the flow of pressurized fluid from compression chamber  140  into discharge manifold  115 . Discharge valve  150  also has a closure member or poppet  170  that is urged into sealing engagement with a sealing member or seat  175  by a biasing member  180 , such as a spring. 
     Flexible connection  195  is configured to reduce the transfer of cyclic loads produced by the reciprocating motion of pump  125  from pump assembly  105  to suction manifold  110 . Such loads cause cyclic deformation of suction manifold  110 , which, in turn, produces pressure pulsations within fluid passing through suction manifold  110 . As previously described, pressure pulsations may disturb downstream instrumentation and communication devices, and/or cause fatigue damage to downstream piping. 
     In the embodiment shown in  FIG. 1 , flexible connection  195  includes a spherically-shaped, elastomeric chamber or body  197  with a flowbore  198  extending therethrough. Flowbore  198  is hydraulically coupled between compression chamber  140  within pump assembly  105  and suction manifold  110 . As such, compression chamber  140 , flowbore  198 , and suction manifold  110  may be said to be in fluid communication with one another. Thus, flowbore  198  enables the flow of fluid from suction manifold  110  to pump assembly  105 . During operation of pump  125 , elastomeric body  197  flexes, twists, and otherwise deforms in response to movement of pump assembly  105 . However, due to the flexible nature of body  197 , structural loads to suction manifold  110  due to movement of pump assembly  105  are reduced, in comparison to that which would otherwise be experienced in the absence of a flexible coupling between pump assembly  105  and suction manifold  110 . As a result, cyclic deformation of suction manifold  110  due to the reciprocating motion of pump  125  and pressure pulsations resulting therefrom are also reduced. 
     Turning now to  FIG. 2 , flow straightener  200  includes a conduit segment  205  having a flowbore  210  extending therethrough and generally defined by the conduit segment&#39;s generally cylindrical inner surface  250 . Flowbore  210  enables fluid communication between suction manifold  110  ( FIG. 1 ) and flowbore  198  ( FIG. 1 ) of flexible connector  195 . Flow straightener  200  further includes a plurality of pins  260  extending substantially radially from segment  205  into flowbore  210 . In the embodiment shown, each pin  260  is coupled to segment  205  by a flexible insert  265 , and supports a vane  270 . Vanes  270  essentially subdivide flowbore  210  into an equal number of flow channels  425  through which fluid passes. Flow straightener  200  preferably includes more than two vanes  270  positioned circumferentially within flowbore  210  an equal distance apart. In this embodiment, flow straightener  200  has four equally spaced vanes  270 . 
     Conduit segment  205  further includes a plurality of axially extending throughbores  215  circumferentially spaced about segment  205  near its perhiphery. Throughbores  215  enable coupling of flow straightener  200  between flexible connection  195  and suction manifold  110 . To couple flow straightener  200  between flexible connection  195  and suction manifold  110 , as shown in  FIG. 1 , a bolt  220  is inserted through each throughbore  215  and adjacent, aligned bores in flexible connector  195  and suction manifold  110 , and secured in position with a threaded nut  225 . Referring again to  FIG. 2 , in this embodiment, flow straightener  200  includes eight throughbores  215  equally spaced about the periphery of segment  205 . However, in other embodiments, flow straightener  200  may include fewer or more throughbores  215 . Moreover, in such embodiments, throughbores  215  may be nonuniformly spaced about segment  205 . 
     Conduit segment  205  further includes a plurality of throughbores  230 , each throughbore  230  extending radially between a generally cylindrical outer surface  235  of segment  205  and flowbore  210 . As shown in  FIG. 3 , which is a radial cross-section of segment  205  taken along a plane that bisects throughbores  230 , each throughbore  230  includes a radially inner portion  240  and a radially outer portion  245  extending therefrom and generally coaxially aligned. Inner portion  240  extends radially outward from an azimuthally, extending inner surface  250  bounding flowbore  210  to outer portion  245 , and is configured to receive an insert  265 . In this embodiment, inner portion  240  is tapered, such that the diameter of inner portion  240  at surface  250  is greater than the diameter of inner portion at its base  255 , which is connected to outer portion  245  of throughbore  230 . Outer portion  245  of throughbore  230  extends radially outward from inner portion  240  to outer surface  235 . In cross-section, the diameter of outer portion  245  may be uniform, as illustrated, or it may be nonuniform. Regardless, in the embodiment shown, outer portion  245  has a diameter that is smaller than the diameter of inner portion  240  at its base  255 . 
     Each flexible insert  265  is generally cup-shaped and is insertable within an inner portion  240  of one throughbore  230 . In this embodiment, flexible inserts  265  are formed of elastomeric material. As best viewed in  FIG. 4 , each flexible insert  265  has a base  275 , a top  280 , a central bore or recess  290 , and an outer surface  285  extending longitudinally between base  275  and top  280 . In this embodiment, insert  265  is generally frustoconical, having a greater diameter at top  280  than at base  275 . So configured, outer surface  285  is tapered to enable insert  265  to be received within inner portion  240  of throughbore  230  such that base  275  of insert  265  is proximate, or abuts, base  255  of inner portion  240 , and top  280  of insert  265  is exposed to flowbore  210 , as shown in  FIG. 3 . 
     Referring still to  FIG. 4 , insert  265  further includes a recess  290  extending longitudinally inward from top  280  toward base  275 . Recess  290  is configured to receive a pin  260 , described in detail below. Further, recess  290  is bounded by an inner surface  295  that is shaped to prevent rotation of pin  260  relative to insert  265  when pin  260  is inserted within recess  290 , as shown in  FIG. 3 . Preferably, recess  290  has a cross-section that is non-circular, such as polygonal, elliptical, or oval in shape. In this embodiment, recess  290  has a hexagonal cross-section. 
     Each pin  260  is configured to be insertable within a recess  290  of an insert  265 . Pin  260  is preferably made from stainless steel for its ability to resist corrosion when exposed to the drilling fluid, but may also be made of other steel alloys or reinforced composite materials. As best viewed in  FIG. 5 , each pin  260  includes a cylindrical portion  300  and a base  305  coupled thereto. A vane  270  is coupled to or formed integrally with cylindrical portion of pin  260 , such that pin  260  supports vane  270 . In this embodiment, vane  270  is coupled to cylindrical portion  300  of pin  260  by means of slot  310  that extends radially through cylindrical portion  300  of pin  260  and substantially bisects pin  260 . Slot  310  is configured to receive vane  270 . In this embodiment, slot  310  is rectangular in cross-section and has a width  315 . Vane  270  is fastened within slot  310  using any suitable attachment means, such as, but not limited to, brazing, gluing, riveting, welding, and/or the use of an epoxy. 
     Base  305  of pin  260  is configured to be received within recess  290  of insert  265 , as shown in  FIG. 3 . In some embodiments, base  305  of pin  260  is vulcanized to insert  265 . Referring still to  FIG. 5 , base  305  of pin  260  has a longitudinally-extending outer surface  320  that is shaped to prevent rotation of base  305  of pin  260  relative to insert  265  when inserted within recess  290 . Preferably, base  305  has a cross-section which is similar in shape to that of recess  290 . In this embodiment, base  305 , like recess  290 , has a hexagonal cross-section. 
     Turning now to  FIG. 6 , each vane  270  has a thickness  325  selected to enable insertion of vane  270  into and through slot  310  of pin  260 , as shown. Where drilling fluid is being conveyed through flow straightener  200 , the material selected for vanes  270  should preferably be made of a corrosion-resistant material. 
     Each vane  270  further includes a tapered nose portion  330  and tail portion  335  extending therefrom. In this embodiment, nose portion  330  has a linear, leading surface  340 , and tail portion  335  that is rectangular in shape. In other embodiments, leading surface  340  may be nonlinear or curved. The taper of nose portion  330  is characterized by a nose angle  365  formed between leading surface  340  and a longitudinally extending outer surface  360  of vane  270 . In the embodiment shown, nose angle  365  is approximately equal to 45 degrees. In other embodiments, however, nose angle  365  may be greater or less than 45 degrees. Nose angle  365  is generally within the range of 30 to 60 degrees, and preferable within the range 30 to 45 degrees. Further, in some embodiments, a leading edge of nose portion  330  is hammed, meaning a small width of the leading edge is folded over itself such that it forms a rigid and slightly rounded leading edge. This results in increased stiffness of the leading edge, and thus nose portion  330 . 
     Further, vane  270  has a length  350 , measured from a tip  355  of nose portion  330  along outer surface  360 , and a width  345 , measured from an end  370  of tail portion  335  along an outer surface  375  normal to surface  360 . In some embodiments, the ratio of length  350  to a diameter  212  ( FIG. 3 ) of flowbore  210  is within the range 1.4 to 1.7. Also, length  350  is preferably at least four times width  345 . Width  345  of vanes  270  is selected such that when assembled within segment  205 , as shown in  FIG. 2 , vanes  270  do not extend into or across a central, core region  440  of flowbore  210 . In some embodiments, the ratio of width  345  to diameter  212  of flowbore  210  is within the range 0.3 to 0.45, and, in the embodiment shown, is about 0.4. Also, the ratio of the diameter of core region  440  to that of flowbore  210  is approximately 0.125 in the example shown. Providing a core region  440  that is free of or unobstructed by vanes  270  is desirable for at least a couple of reasons. First, fluid passing through core region  440  is less turbulent than fluid passing through flowbore  210  outside core region  440 . Thus, there is comparatively less need to reduce fluid turbulence within region  440 , and providing core  440  unobstructed by vanes  270  minimizes the resistance to fluid flow therethrough. 
     Second, because vanes  270  extend longitudinally along flowbore  210 , vanes  270  provide some resistance to fluid flow through drilling fluid system  100 . The capacity of pump  125  must be sufficient to overcome the flow resistance through drilling fluid system  100 , including that resistance created by vanes  270 , in order to deliver pressurized fluid to discharge manifold  115  at a desired rate. Increasing width  345  of vanes  270  beyond that which is needed to reduce fluid turbulence, including by extending vanes  270  fully across flowbore  210 , for example, would further obstruct fluid flow through system  100  and increase the flow resistance which pump  125  must overcome. A consequence of obstructing fluid flow through flowbore  210  too much is that insufficient fluid is provided to pump  125 , which may result in cavitation. 
     Each vane  270  is not entirely rigid, but may flex and elastically bend to some degree as it resists turbulent fluid flow and provides a fluid-straightening effect. This flexure is a result both of the vane&#39;s dimensions, including its substantial length relative to its width, and the substantial narrowness of its thickness in relation to length and width. Such flexure is also provided by attaching vane  270  to pin  260  relatively close to one end, for instance nose  330 , and relatively far from the second end, for instance tail  335 . Still further flexure is provided by employing the resilient insert  265  used in securing pin  260  to conduit segment  205 . 
     Notwithstanding the description above regarding the capabilities of vanes  270  to flex when used in the embodiment described with reference to  FIG. 6 , it should be understood that in other applications, vanes  270  may be positioned so as to be substantially rigid with respect to fluid flow. For example, the materials and dimensions of vanes  270  may be selected to provide substantial rigidity and resist bending and flex under load from turbulent fluid passing through flow straightener  200 . Further, vanes  270  may be rigidly attached to pins  260  and pins  260 , in turn, rigidly secured to conduit segment  205  and in the absence of, for example, resilient members, such as inserts  265  described above. 
     Referring next to  FIGS. 7A and 7B , fluid passes from suction manifold  110  ( FIG. 1 ) through flowbore  210  of flow straightener  200  in a direction indicated by arrow  380 . When inserted and secured within a slot  310  of a pin  260 , each vane  270  is oriented such that vane  270  extends longitudinally in a direction  390  which is substantially parallel to the fluid flow direction  380  with nose portion  330  positioned upstream of tail portion  335 . Moreover, each vane  270  is also oriented such that tip  355  of nose portion  330  is proximate inner surface  250  of conduit segment  205 , rather than proximate core region  440 , as best shown in  FIG. 7B . In other words, each vane  270  is positioned such that surface  360 , having the longest edges  362 , is the radially outermost surface and the opposing surface  364 , having edges  366  that are shorter than edges  362 , is the radially innermost surface. 
     Although each vane  270  extends longitudinally in direction  390  generally parallel to the flow direction  380 , direction  390  need not be perfectly parallel to the flow direction  380 . Rather, in some embodiments, illustrated by  FIGS. 8A and 8B  (the latter figure showing only a single vane  270  for clarity), direction  390  is angularly offset relative to the flow direction  380 . As shown, each vane  270  extends in direction  390 , which is angularly offset from flow direction  380  by an angle  395 . This arrangement in which vane  270  is positioned so as to deviate at an angle  395  relative to the intended flow direction  380  or a longitudinal axis of conduit segment  205  may be best described as one in which vane  270  is longitudinally skewed relative to the intended flow direction  380  or the longitudinal axis of conduit segment  205 . In such embodiments, angle  395  is generally less than 20 degrees, and is preferably within the range 5 to 15 degrees. In other embodiments, however, vanes  270  may in fact be oriented, longitudinally speaking, parallel to the flow direction  380 . In such cases, angle  395  is equal to zero. Furthermore, in some embodiments, angle  395  may vary from one vane  270  to the next. 
     Furthermore, the width  345  ( FIG. 6 ) of each vane  270  also extends radially within flowbore  210  in a direction  400  that is generally normal to surface  250  of conduit segment  205 . However, direction  400  need not be perfectly normal to surface  250 . Rather, in some embodiments, as illustrated by  FIGS. 9A and 9B , each vane  270  is retained in pin  260  in a skewed relationship to a plane  405  that is normal to surface  250  such the generally planar side  368  of vane  270  forms an angle  410  with plane  405 . This arrangement is one in which vane  270  is retained in conduit segment  205  in a position such that, when viewed from either the upstream or the downstream end, the cross-section of vane  270  taken where it is retained by pin  260  is not radially aligned with plane  405  (meaning does not extend along plane  405 ), but is at an angle  410  to plane  405 . This arrangement may be referred to herein as a condition in which the vane is radially skewed relative to plane  405 . Since a plane  405  that is normal to surface  250  contains or is coincident to a radius of conduit segment  205 , this arrangement also is described as one in which vane  270  is retained in conduit segment  205  in a position such that, when viewed from either the upstream or the downstream end, the cross-section of vane  270  taken where it is retained by pin  260  is not radially aligned with a radius of conduit segment  205  (meaning does not extend along the radius), but is at an angle  410  to the radius, and may be referred to herein as a condition in which the vane is radially skewed relative to the radius of conduit segment  205 . In other embodiments, however, vanes  270  may in fact be oriented, radially speaking, normally to surface  250 . In such cases, angle  410  is equal to zero. 
     Referring again to  FIG. 1 , during operation of pump  125 , piston  185  reciprocates within cylinder  190 . When piston  185  moves to expand the volume within cylinder  190 , fluid pressure behind poppet  155  decreases. In response, discharge valve  150  closes, meaning biasing member  180  and the fluid decrease behind poppet  155  cause poppet  170  to seat against sealing member  175 . At the same time, the pressure of fluid from suction manifold  110  causes poppet  155  to compress biasing member  165  and unseat from sealing member  160 . Once poppet  155  disengages sealing member  160 , suction valve  145  is open, and fluid from suction manifold  110  enters compression chamber  140 . When piston  185  reverses direction, decreasing the volume within cylinder  190  and increasing the pressure of fluid contained with compression chamber  140 , suction valve  145  closes, and discharge valve  150  opens to allow pressurized fluid from compression chamber  140  into discharge manifold  115 . While pump  125  is operational, this cycle repeats, often at a high cyclic rate, and pressurized fluid is continuously fed to the fluid destination. 
     Drilling fluid system  100  includes flow straightener  200  which is configured to reduce the turbulence of fluid passing from suction manifold  110 . Vanes  270  of flow straightener  200  subdivide turbulent fluid from suction manifold  110  between channels  425  through which the fluid passes. In doing so, vanes  270  redirect or straighten the fluid flow such that it is more uniform, and therefore less turbulent. 
     Further, vanes  270  are configured to minimize the disruption to the fluid flow caused by the initial contact of the fluid with vanes  270 . Fluid passing from suction manifold  110  into flow straightener  200  initially contacts vanes  270  over leading surfaces  340  of nose portions  330 . Due to the taper of nose portions  330 , meaning the angular orientation of leading surfaces  340  relative to the fluid flow direction  380 , contact between the fluid and vanes  270  gradually increases over the length of leading surfaces  340 . Were nose portions  330  not tapered and leading surfaces  340  normal to the fluid flow direction  380 , contact between the fluid and vanes  270  would not be a gradual, but a blunt interaction that creates additional turbulence in the fluid. Thus, the taper of nose portion  330  reduces this undesirable effect. 
     Moreover, vanes  270  are oriented to further minimize the disruption to the fluid flow. Fluid passing from suction manifold  110  into flow straightener  200  is typically more turbulent in a near-wall region  435  ( FIG. 7A ) proximate inner surface  250  of segment  205  than it is within core region  440  ( FIG. 7B ) of flowbore  210 . Because vanes  270  are also oriented such that tips  355  of nose portions  330  are within turbulent near-wall region  435  proximate inner surface  250  of segment  205 , the more turbulent fluid passing through near-wall region  435  initially contacts vanes  270  over a relatively small area, specifically, tips  355 . Contact between the turbulent fluid and vanes  270  then gradually increases as the fluid engages and passes over at least a portion of tapered leading surfaces  340  of vanes  270 . Enabling the turbulent fluid to gradually engage vanes  270  in this manner reduces the tendency for initial contact between the turbulent fluid and vane surfaces  340  to create additional turbulence within the fluid. 
     Still further, the shape of pins  260  may be selected to minimize the resistance of pins  260  to, and therefore the pressure decrease of, fluid flow passing through flowbore  210  of flow straightener  200 . Fluid passing from suction manifold  110  into flow straightener  200  initially contacts each tapered nose  330  of vanes  270  and is divided or separated into two fluid streams. Each stream then flows along opposite sides of vane  270  toward cylindrical portion  300  of pin  260  supporting vane  270 . When each stream contacts portion  300 , it flows around portion  300 . Because portion  300  is cylindrical in shape, a low pressure region is created proximate the apex zone  262  of pin  260 . Fluid is drawn into this low pressure region, and assumes the velocity of fluid near the surface of pin  260 . After flowing around pin  260 , each fluid stream continues along length  350  of vane  270  toward tail  335  where both streams reunite. Length  350  of vane  270  may be selected such that both streams have substantially the same velocity when they reunite at tail  335  of vane  270 . The effect of cylindrically-shaped portion  300  of pin  260  enables a lower pressure drop across pin  260  than would otherwise be obtained with a pin having a different shape. 
     As fluid passes through flow straightener  200 , the size of the radial cross-section of each outer portion  245  of throughbores  230  in conduit segment  205  relative to that of the radial cross-section of each inner portion  240  in which inserts  265  are disposed enable pins  260  to maintain the position of vanes  270 . Fluid passing through flowbore  210  of flow straightener  200  exerts pressure loads on tops  280  of inserts  265 . Because the diameter of outer portions  245  of throughbores  230  is smaller than that of inner portions  240  at their bases  255 , inserts  265  are prevented from disengaging throughbores  230  by extruding through outer portions  245  in response to the pressure load. Instead, flexible inserts  265  are simply compressed by the pressure loads within inner portions  240  of throughbores  230 , and the pre-selected positions of vanes  270  are maintained. 
     Also, as fluid passes through flow straightener  200 , the cross-sectional shapes of recesses  290  of inserts  265  and bases  305  of pins  260  disposed therein enable pins  260  to maintain the orientation of vanes  270 . Fluid passing through flowbore  210  of flow straightener  200  contacts vanes  270  and imparts loads thereto. Even so, vanes  270  are prevented from rotating in response to the loads due to the interaction between recesses  290  of inserts  265  and bases  305  of pins  260 . As described above, the shape of surfaces  295 , which bound recesses  290  in which bases  305  of pins  260  are disposed, and the shape of surfaces  320  of bases  305  are configured to prevent rotation of pins  260  relative to inserts  265 . 
     As described, flow straightener  200  includes a number of features, each of which enables the reduction of the turbulence within fluid passing from suction manifold  110 . Consequently, fluid entering valve assembly  120  contacts poppet  155  of suction valve  145  more uniformly, reducing the tendency for poppet  155  to flutter, or act unstably. Moreover, fewer bubbles are created as the comparatively less turbulent fluid passes around poppet  155  into compression chamber  145 . Reduced fluttering of poppet  155  and fewer bubbles within compression chamber  145  enable increased efficiency of pump  125 . Also, fewer pressure pulsations are created within the fluid during the compression cycle of pump  125 . 
     Furthermore, flow straightener  200  is configured to dampen pressure pulsations created within fluid upstream of flow straightener  200 , such as those created by cyclic deformation of suction manifold  110 . Pressure pulsations created in fluid upstream of flow straightener  200  are carried by the fluid as the fluid flows toward and into flow straightener  200 . When the fluid contacts vanes  270  of flow straightener  200 , pressure forces, or loads, are imparted to vanes  270  by the fluid. The imparted loads are then transferred through vanes  270  and pins  260  coupled thereto to flexible inserts  265 , where the pressure loads are absorbed. 
     The above-described embodiment is directed to a drilling fluid system  100  for pressurizing drilling mud. Drilling fluid system  100  includes a flow straightener  200  in accordance with the principles disclosed herein. Flow straightener  200  is positioned downstream of suction manifold  110 , and is configured to reduce the turbulence of and pressure pulsations propagated by drilling fluid passing therethrough. Reductions in flow turbulence enable increased efficiency of pump  125 . Moreover, reductions in pressure pulsations propagated by the drilling fluid decrease disturbances to downhole instrumentation and lessen the likelihood of fatigue damage to downstream piping. 
     One of ordinary skill in the art will readily appreciate the applicability of the flow straightener in other positions within drilling fluid system  100 . For example, a flow straightener may be positioned on the discharge side of pump assembly  105 . In such embodiments, it is sometimes desirable for fluid flow on the discharge side to have a higher level of turbulence, as compared to that of fluid entering the suction side of pump assembly  105 . Consequently, angle  395  and/or angle  410  may be selectably adjusted to increase the turbulence of fluid passing through the flow straightener. 
     Also, one of ordinary skill in the art will readily appreciate the applicability of a flow straightener in accordance with the principles disclosed herein within other types of fluid conveyance systems wherein it is desired to reduce fluid turbulence and/or dampen pressure pulsations propagated by a fluid. Thus, the flow straightener disclosed herein is not limited to the context of a drilling fluid system. 
     While various embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings herein. The embodiments herein are exemplary only, and are not limiting. Many variations and modifications of the apparatus disclosed herein are possible and within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.