fig2 illustrates an example fluidic oscillator 100 . example fluidic oscillator 100 comprises a housing 200 that encloses at least one insert 300 . insert 300 contains flowpath 302 , which generates the oscillation effect that drives the fluid pulses . fig2 displays a partially cutaway view of housing 200 to better display insert 300 and flowpath 302 . the example housing shown in fig2 is cylindrical , with a circular cross - section ; housing 200 may alternatively take other forms , including , but not limited to , a bar - shaped form with a rectangular cross - section . alternatively , housing 200 may include multiple inserts , as discussed in more detail later in this disclosure . a fluid flowline 400 supplies fluid to fluidic oscillator 100 . fluid flowline 400 may fit inside housing 100 or alternatively connect to fluidic oscillator 100 via a transitional piece ( not shown in fig2 ). housing 200 and insert 300 may be formed of any material capable of withstanding the environment in which fluidic oscillator 100 will be used . if , for example , fluidic oscillator 100 will be used to clean a flowline or well bore containing formation fluids , housing 200 and insert 300 may be formed of metal . alternatively , housing 200 and insert 300 may be formed of a phenolic plastic capable of withstanding a downhole environment . fluidic oscillator 100 &# 39 ; s design allows the user to replace insert 300 without replacing fluidic oscillator 100 entirely . that is , if flowpath 302 erodes after heavy use , insert 300 may be replaced and housing 200 may be reused . the use of an insert 300 also permits customization of the flowpath in the field . fig3 and 4 illustrate an example insert 300 . as shown in fig3 , insert 300 has flowpath 302 cut into its upper surface 301 ; flowpath 302 may be created through traditional machining processes , such as milling , casting , or molding or may be generated through an electrical discharge machining ( edm ) process . for ease of illustration , fig4 illustrates a plan view of flowpath 302 in upper surface 301 . fluid supplied by fluid flowline 400 enters into flowpath 302 via interior flowline 303 and passes through inlet 304 . interior flowline 303 may decrease in width as it approaches inlet 304 to form a focused jet as it enters inlet 304 . the fluid passes through inlet 304 into chamber 305 . chamber 305 is defined by two outwardly projecting sidewalls 306 and 307 and has an upstream end 308 and a downstream end 309 . a feedback cavity 310 is disposed at downstream end 309 . flowpath 302 may have the configuration of the flowpath described and depicted in the application for united states patent entitled “ apparatus and method for creating pulsating fluid flow , and method of manufacture for the apparatus ,” ser . no . 10 / 808 , 986 filed on mar . 25 , 2004 , assigned to the assignee of this disclosure . the fluid forms a jet as it streams from inlet 304 into chamber 305 in example insert 300 . as the jet leaves inlet 304 , the fluid tends to cling to one of the two outwardly projecting sidewalls 306 or 307 . this tendency is a result of the well - documented phenomenon known as the “ coanda effect .” when the fluid exits inlet 304 as a jet into chamber 305 , it draws any fluid between the jet and one of the two outwardly projecting sidewalls 306 or 307 into the jet . for example , the jet may first draw fluid between the jet and outwardly projecting sidewall 306 into the jet . the temporary absence of fluid between the jet and outwardly projecting sidewall 306 creates a low - pressure region . before the ambient pressure in chamber 305 can restore pressure to this region , the jet is drawn to outwardly projecting sidewall 306 and clings to its surface . the result of this coanda effect is that the fluid enters chamber 305 along one of the outwardly projecting sidewalls 306 or 307 , rather than through the center of chamber 305 . the pulsating action of the fluid flow generated by exemplary fluidic oscillator 100 arises from switches in the fluid flow from along outwardly projecting sidewall 306 to along outwardly projecting sidewall 307 , and vice versa . at least two feedback passages 311 and 312 are disposed on opposite sides of chamber 305 to help achieve these switches . two opposed entrances 313 and 314 leave from downstream end 309 of chamber 305 . two opposed exits 315 and 316 to feedback passages 311 and 312 join upstream end 308 of chamber 305 . to continue with the example of the previous paragraph , a portion of the fluid traveling alongside outwardly projecting sidewall 306 will reach opposed entrance 313 and be diverted into feedback passage 311 . most of the fluid that enters feedback passage 311 will exit insert 300 through exit flowline 317 , as discussed later in this disclosure in more detail . the remaining fluid that enters feedback passage 311 , however , will return to chamber 305 through opposed exit 315 . the entry of this fluid into chamber 305 disturbs the path of the jet of fluid issuing from inlet 304 such that the jet no longer adheres to outwardly projecting sidewall 306 . the jet of fluid instead will adhere to outwardly projecting sidewall 307 in the same manner as it adhered to outwardly projecting sidewall 306 . the jet of fluid will then travel along outwardly projecting sidewall 307 , and a portion of the fluid will enter feedback passage 312 through opposed entrance 314 . most of the fluid will exit insert 300 through exit flowline 318 , as discussed in detail later in this disclosure . the remaining fluid in feedback passage 312 will continue to opposed exit 316 and return to chamber 305 . as with the fluid entering chamber 305 from opposed exit 315 , the fluid passing through opposed exit 316 will disturb the flow of fluid along the surface of outwardly projecting sidewall 307 . the fluid will then switch from traveling alongside outwardly projecting sidewall 307 to traveling alongside outwardly projecting sidewall 306 , and the cycle will repeat . at any time when fluid flows along outwardly projecting sidewall 306 and through feedback passage 311 , no fluid flows along outwardly projecting sidewall 307 or through feedback passage 312 . the converse is also true : no fluid flows along outwardly projecting sidewall 306 or through feedback passage 311 while fluid flows along outwardly projecting sidewall 307 and through feedback passage 312 . this oscillation of fluid from one half of insert 300 to the other helps create the desired pulsating fluid flow . in particular , as fluid travels through either feedback passage 311 or 312 , exit flowline 317 or 318 , respectively , will draw off a portion of the passing fluid . fluid entering exit flowline 317 or 318 will exit insert 300 . the effect of the oscillation of the fluid between outwardly projecting sidewall 306 and outwardly projecting sidewall 307 is that fluid will exit through only one exit flowline 317 or 318 at a time . thus insert 300 will emit pulses of fluid from one side to the other , in succession . exit flowlines 317 and 318 in this example insert 300 are perpendicular to feedback passages 311 and 312 , respectively . exit flowlines 317 and 318 may , however , take any number of different paths , as described in the application for united states patent entitled “ apparatus and method for creating pulsating fluid flow , and method of manufacture for the apparatus ,” ser . no . 10 / 808 , 986 filed on mar . 25 , 2004 , assigned to the assignee of this disclosure . for example , fluidic oscillator 100 might be used to clean the interior walls of a fluid flowline or a well bore . if exit flowlines 317 and 318 are perpendicular to feedback passages 311 and 312 , the pulses of fluid emitted from insert 300 could jet from the sides of fluidic oscillator 100 ( as discussed below ) onto the interior walls of the well bore , cleaning their surfaces of collected debris and scale . the best path for the exit flowlines will depend upon how the apparatus will be used , as will be readily apparent to a person of ordinary skill in the art having the benefit of this disclosure . feedback cavity 310 , disposed at downstream end 309 of chamber 305 , further promotes the oscillation of fluid flow in insert 300 . while a portion of the fluid traveling along outwardly projecting sidewalls 306 and 307 is directed into opposed entrances 313 and 314 , the remainder of the fluid exits chamber 305 into feedback cavity 310 . if the fluid enters feedback cavity 310 after traveling along outwardly projecting sidewall 306 , the fluid will follow a clockwise path around feedback cavity sidewall 319 and return to chamber 305 near outwardly projecting sidewall 307 . this fluid flow will destabilize the fluid flow near outwardly projecting sidewall 307 . the added instability amplifies the oscillation effect produced by feedback passage 311 by drawing fluid to outwardly projecting sidewall 307 from outwardly projecting sidewall 306 . the cycle then reverses , with fluid entering from outwardly projecting sidewall 307 and following a counterclockwise path in feedback cavity 310 to near outwardly projecting sidewall 306 . example feedback cavity 310 has a rounded shape . any volume that extends beyond opposed entrances 313 and 314 may serve as a feedback cavity 310 , regardless of the shape the volume assumes . at least one forward jet 320 may be present at feedback cavity sidewall 319 . forward jet 320 may be useful for the well bore and fluid flowline cleaning applications discussed previously in this disclosure . for example , if fluidic oscillator 100 travels within a fluid flowline with forward jet 320 at the leading edge , forward jet 320 will jet fluid ahead of fluidic oscillator 100 and could thus clear debris from the path of fluidic oscillator 100 . forward jet 320 should have a smaller cross - section than feedback passages 311 and 312 , to prevent disturbances to the pulsating action . insert 300 is wedge - shaped , as illustrated in fig3 . upper surface 301 , a corresponding lower surface 330 ( not shown in fig3 ), and two side surfaces 331 and 332 ( not shown ). each side slopes such that insert 300 is narrower at its downstream end 333 than at its upstream end 334 . the angle of the slope may vary between approximately 0 degrees to approximately 15 degrees . for certain flowline cleaning jobs , a 1 . 5 degree downward slope from upstream end 334 to downstream end 333 may be desirable . the slope of upper surface 301 and lower surface 330 is made obvious in fig5 , which illustrates a side view of insert 300 . the tapered wedge shape of insert 300 has the benefit of allowing flowpath 302 to maintain a substantially constant depth inside insert 300 with only a gradual slope downstream in the height of the walls that form flowpath 302 . the walls maintain a substantially constant height across the width of the insert at any one location along the fluid flowpath . rather , the height of the walls will only gradually decrease toward the downstream end of the insert . in contrast , if insert 300 assumed a cylindrical form , the height of the walls that form flowpath 302 would be much shorter near feedback outlets 317 and 318 than near chamber 305 . moreover , the wedge shape for the insert provides a substantially flat surface for flowpath 302 . this configuration enhances the performance of fluidic oscillator 100 , as compared to , for example , a cylindrical insert which would have a curved surface for the flowpath . the wedge shape is also more conducive to precision edm processes and field customization than a cylindrical form would be . inserts may be customized for particular jobs ; a given fluidic oscillator may include multiple inserts that may be switched before use , even on site , depending on the job . the wedge shape of insert 300 also permits a tight , fluid - impermeable fit directly between housing 200 and insert 300 . that is , insert 300 may be designed to fit inside housing 200 such that all the outside surfaces of insert 300 directly contact the interior of housing 200 and create a fluid - tight seal that prevents any fluid from escaping from flowpath 302 . the direct housing - to - insert seal eliminates the need for any additional sealing structure and thus eliminates a manufacturing and operational variable . the insert may also assume alternate forms . for example , the insert may be a rectangular block , rather than a wedge . fig6 illustrates a top view of a rectangular insert 340 . a tab 341 may be provided to lock insert 340 into housing 200 , which is discussed in greater detail later in this disclosure . the rectangular profile of insert 340 is evident in fig7 , which illustrates a side view of insert 340 . a second tab 342 may also be provided on lower surface 343 of insert 340 . fig8 displays another sample insert 350 . insert 350 provides enough material to support walls 351 to surround flowpath 302 , but not very much more . thus , rather than assuming a wedge or rectangular shape , the insert assumes a shape that models flowpath 302 . interior flowline 353 and two exit flowlines 354 and 355 may attach to specially - adapted notches in housing 200 , which is discussed in greater detail later in this disclosure . fluidic oscillator 100 also comprises a housing 200 . examples of housing 200 are illustrated in fig9 , 10 , 11 and 12 . fig9 illustrates an outside view of a housing 200 . port 201 is positioned to allow fluid exiting from exit flowline 317 in insert 300 to escape housing 200 . although not visible in fig9 , a corresponding port 202 is located on the opposite side of housing 200 ( 180 degrees from port 201 ). port 202 allows fluid exiting from exit flowline 318 in insert 300 to escape housing 200 . slot 203 in end 204 of housing 200 , fits directly around downstream end 333 of insert 300 . fig1 illustrates longitudinal cross - sectional views of housing 200 , with ports 201 and 202 at the top and bottom , respectively . to achieve the fluid - tight seal , housing 200 may include a recess 205 that is shaped to receive and directly engage the insert . the insert fits inside recess 205 , sliding in through entrance 206 and slot 203 until the insert mates with the housing . if the insert is tapered , like insert 300 , recess 205 must be tapered to fit closely over the insert . surfaces 301 , 330 , 331 and 332 of insert 300 , shown in fig3 , 4 , and 5 , for example , may create a fluid - tight seal with an inside surface 210 of housing 200 . this fluid - tight seal eliminates the need for any intervening sealing mechanism . just inside entrance 206 , a series of threads 208 is provided to engage a fluid flowline 400 ; the threads may be either male or female or otherwise customized to accommodate a specific fluid flowline 400 . fig1 illustrates an additional cross - sectional view of housing 200 in which housing 200 has been rotated about a central longitudinal axis from the view in fig1 . if the insert is not tapered , but instead is rectangular , the recess may also be rectangular . the recess may also be rectangular , or otherwise shaped , to accept an insert that is formed only of the walls of the flowpath , such as insert 350 . another example housing 250 for insert 350 is shown in fig1 ; recess 251 is rectangular . housing 200 may then have slots 252 and 253 that are specially adapted to accommodate and retain exit flowlines 354 and 355 . alternatively , a fluidic oscillator may include a housing designed to accommodate multiple inserts . such a fluidic oscillator may allow for a higher volume of fluid to pass through this example fluidic oscillator than fluidic oscillators including only one insert , thereby increasing , for example , the potential cleaning performance of the fluidic oscillator . fig1 illustrates an example housing 260 with four recesses 261 , 262 , 263 , and 264 spaced substantially evenly about a central longitudinal axis of housing 260 , or approximately 60 degrees apart . support 265 of housing 260 maintains the spacing between each insert and provides the structure for recesses 261 , 262 , 263 , and 264 . each recess 261 , 262 , 263 , or 264 may enclose one insert , similar to the recesses described previously in this disclosure . alternatively , housing 260 may include recesses large enough to accommodate more than one insert . as one of ordinary skill in the art having the benefit of this disclosure will realize , housing 260 may enclose any number of inserts spaced at any interval ; the housing 260 shown in fig1 is merely an example . the inserts will contain flowpaths that generate fluid pulses in the manner described earlier in this disclosure . housing 260 also provides at least one port , not shown in fig1 , to allow fluid to escape from each insert , similar to ports 201 and 202 . a single high - volume port may be provided . however , multiple ports for the example fluidic oscillator may be aligned such that fluid jets from housing 260 in multiple directions at the same time . for instance , housing 260 may have multiple ports for each insert , allowing the fluidic oscillator to jet fluid in substantially 360 degrees . such a configuration would allow , for example , the fluidic oscillator to clear debris from nearly the entire inner circumferences of a flowline and potentially reduce the need for multiple cleaning passes by the fluidic oscillator through the flowline . the present invention is well - adapted to carry out the objects and attain the ends and advantages mentioned , as well as those that are inherent therein . while the invention has been depicted , described , and is defined by reference to the exemplary embodiments of the invention , such a reference does not imply a limitation on the invention , and no such limitation is to be inferred . the invention is capable of considerable modification , alteration , and equivalents in form and function , as will occur to those ordinarily skilled in the pertinent arts and having the benefit of this disclosure . the depicted and described embodiments of the invention are exemplary only and are not exhaustive of the invention . consequently , the invention is intended to be limited only by the spirit and scope of the appended claims , giving full cognizance to equivalents in all respects .