Patent Publication Number: US-2020291892-A1

Title: Blocker door assembly having a thermoplastic blocker door for use in a turbine engine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/250,253 filed on Aug. 29, 2016, and which is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Exemplary embodiments disclosed herein relate generally to engine assemblies, and more particularly to a thermoplastic blocker door that may be utilized with an engine assembly. 
     Engine assemblies may include a fan assembly, a core gas turbine engine enclosed in an annular core cowl, and a fan nacelle that surrounds a portion of the core gas turbine engine. The fan nacelle is generally spaced radially outward from the annular core cowl such that the core cowl and the fan nacelle form a fan duct terminating in a fan exit nozzle. At least some engine assemblies include a thrust reverser assembly. The thrust reverser assembly may include a first fixed cowl and a second cowl that is axially translatable with respect to the first cowl. At least some thrust reverser assemblies include blocker doors or panels that are actively moved into the bypass duct as the thrust reverser is deployed through drag links or other mechanical means to block or impede the flow of bypass air through the fan exit nozzle. The bypass fan air may be diverted to provide reverse thrust for example through a series of turning vanes disposed in a cascade box. 
     At least some known blocker doors are fabricated from upper and lower skins that surround an aluminum honeycomb core coupled to the skins by an adhesive. The honeycomb core may include a denser portion for structural reasons and a less dense portion subject to less structural loads. Additionally, the denser honeycomb core portion may be filled in with a potting compound to enable the honeycomb core to sustain higher loads. However, in addition to increasing the weight of the blocker door, the potting compound has an undesirable effect on the sound attenuation characteristics of the honeycomb core. 
     BRIEF DESCRIPTION 
     In one aspect, a blocker door assembly for use in a gas turbine engine is provided. The blocker door assembly includes a panel, a core integrally formed with the panel, and a plurality of mounting structures extending from at least one of the panel and the core. The plurality of mounting structures are integrally formed with the core and the panel such that the panel, the core, and the mounting structures are co-molded from a thermoplastic material. 
     In another aspect, a blocker door assembly for use in a gas turbine engine is provided. The blocker door assembly includes a panel, at least one stiffening rib integrally formed with the panel, and a plurality of mounting structures extending from at least one of the panel and the at least one stiffening rib. The plurality of mounting structures are integrally formed with the at least one stiffening rib and the panel such that the panel, the at least one stiffening rib, and the mounting structures are co-molded from a thermoplastic material. 
     In yet another aspect, a method of manufacturing a blocker door for use in a gas turbine engine is provided. The method includes forming a panel from a thermoplastic material and integrally forming a core with the panel from the thermoplastic material. The method also includes co-molding a plurality of mounting structures with the panel and the core from the thermoplastic material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an exemplary engine assembly. 
         FIG. 2  is an exploded view of a portion of the engine assembly shown in  FIG. 1   
         FIG. 3  is a side schematic view showing an exemplary thrust reverser assembly in a stowed disposition. 
         FIG. 4  is a side schematic view showing the thrust reverser assembly shown in  FIG. 3  in a fully deployed disposition. 
         FIG. 5  is a perspective view of an exemplary blocker door assembly for use with the thrust reverser assembly shown in  FIG. 3 . 
         FIG. 6  is a top perspective view of one implementation of a blocker door body portion for use with the blocker door assembly shown in  FIG. 5 . 
         FIG. 7  is a bottom perspective view of the blocker door body portion shown in  FIG. 6 . 
         FIG. 8  is an exploded cross-sectional side view of another implementation of a blocker door for use with the blocker door assembly shown in  FIG. 5   
         FIG. 9  is an exploded top view of the blocker door shown in  FIG. 8 . 
         FIG. 10  is a flow chart illustrating an exemplary method of manufacturing the blocker door shown in  FIG. 5 . 
         FIG. 11  is a perspective view of a compression molding assembly that may be used to mold the blocker door body portion shown in  FIG. 6 . 
         FIG. 12  is a side view of the compression molding assembly prior to molding of the blocker door body portion. 
         FIG. 13  is a side view of the compression molding assembly after molding of the blocker door body portion. 
         FIG. 14  is a perspective bottom view of a ram assembly that may be used with the compression molding assembly. 
         FIG. 15  is a perspective cross-sectional view of a portion of the compression molding assembly illustrating a ram plate and a plurality of core inserts. 
         FIG. 16  is a perspective cross-sectional view of a portion of the compression molding assembly illustrating the ram plate and the plurality of core inserts. 
         FIG. 17  is a perspective view of an ejector assembly that may be used with the compression molding assembly. 
         FIG. 18  is a perspective view of a lower forming assembly that may be used with the compression molding assembly. 
         FIG. 19  is a bottom perspective view of the lower forming assembly shown in  FIG. 18  illustrating a plurality of removable mounting structure inserts. 
         FIG. 20  is a flow chart illustrating an exemplary method of manufacturing the blocker door using the compression molding assembly. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments herein describe a blocker door assembly for use in a gas turbine engine. The blocker door assembly includes a blocker door including plurality of a mounting structures and a body portion integrally formed with the mounting structures. Furthermore, the body portion is formed from a thermoplastic material using a thermoplastic forming process, such as, but not limited to, injection molding and compression molding. The blocker door also includes a facesheet coupled to the body portion, wherein the facesheet is also formed from a thermoplastic material. As such, the body portion and facesheet are able to be thermally or adhesively bonded together to form an integrated, single-piece component. 
     As described herein, the integrally formed thermoplastic blocker door has a number of advantages over conventional blocker doors made from different materials that are coupled together. For example, conventional blocker doors are fabricated from upper and lower skins that surround an aluminum honeycomb core coupled to the skins by an adhesive. The aluminum honeycomb core often includes standardized cell height and wall thickness. A portion of the honeycomb core may be filled in with a potting compound to enable the honeycomb core to sustain higher loads if the standardized sizes do not meet specifications. However, in addition to increasing the weight of the blocker door, the potting compound has an undesirable effect on the sound attenuation characteristics of the aluminum honeycomb core. The use of thermoplastic materials avoids the constraints of utilizing standard sized honeycomb and also avoids the use of the potting material filling of the honeycomb because the cell height and wall thickness can be customized to meet desired specification. Furthermore, different portions of the honeycomb body portion may have different cell sizes to account for different loading or noise attenuation requirements. Such customization of the honeycomb cell size enables increased noise attenuation. Additionally, the use of thermoplastic materials to replace aluminum skin and honeycomb results in both a reduced weight of the blocker door and lower cost due to reduced material and labor costs. 
     The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. 
     Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, “approximately”, and “substantially”, are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged; such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. 
     As used herein, the terms “first”, “second”, and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The term “low coefficient of thermal expansion material” refers to a material which grows relatively less as the temperature increases. 
     As used herein, the terms “axial” and “axially” refer to directions and orientations that extends substantially parallel to a centerline of the turbine engine. The term “forward” used in conjunction with “axial” or “axially” refers to moving in a direction toward the engine inlet, or a component being relatively closer to the engine inlet as compared to another component. The term “aft” used in conjunction with “axial” or “axially” refers to moving in a direction toward the engine outlet, or a component being relatively closer to the engine outlet as compared to another component. Moreover, the terms “radial” and “radially” refer to directions and orientations that extends substantially perpendicular to the centerline of the turbine engine. 
     All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise) are only used for identification purposes to aid the reader&#39;s understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary. 
     Referring initially to  FIG. 1 , a schematic side section view of a gas turbine engine  10  is shown. The function of the gas turbine engine is to extract energy from high pressure and temperature combustion gases and convert the energy into mechanical energy for work. The gas turbine engine  10  has an engine inlet end  12  wherein air enters a core engine  13  after passing through a fan section  18 . An engine nacelle  19  surrounds core engine  13  and fan section  18  such that a bypass duct  22  is defined between an outer wall  23  of core engine  13  and nacelle  19 . Core engine  13  is defined generally by a compressor  14 , a combustor  16 , a multistage high pressure turbine (HPT)  20 , and a separate low pressure turbine (LPT)  21 . Collectively, the core engine  13  provides thrust or power during operation. The gas turbine engine  10  may be used for aviation, power generation, industrial, marine or the like. 
     In operation, air enters through the air inlet end  12  of the engine  10  and moves through at least one stage of compression where the air pressure is increased and directed to the combustor  16 . The compressed air is mixed with fuel and burned providing the hot combustion gas which exits the combustor  16  toward the high pressure turbine  20 . At the high pressure turbine  20 , energy is extracted from the hot combustion gas causing rotation of turbine blades which in turn cause rotation of a first shaft  24  about engine axis  26 . The shaft  24  passes toward the front of the engine to continue rotation of the one or more compressor stages  14 , a fan section  18  or inlet fan blades, depending on the turbine design. The fan section  18  is connected by a second shaft  28  to LPT  21  and creates thrust for the turbine engine  10  by exhausting air through an outlet end  15  of engine  10 . LPT  21  may also be utilized to extract further energy and power additional compressor stages. 
     With reference to  FIGS. 2-4 , in an exemplary embodiment, engine  10  includes a thrust reverser assembly  100  includes a translatable cowl member  102  that defines a portion of nacelle  19 .  FIG. 2  is an exploded view of thrust reverser assembly  100 .  FIG. 3  is a side schematic view of thrust reverser assembly  100  illustrating translatable cowl member  102  and a blocker door assembly  104  a first operational position (i.e., a stowed position).  FIG. 4  is a side schematic view of thrust reverser assembly  100  illustrating translatable cowl member  102  and blocker door assembly  104  a second operational position (i.e., fully translated). When the translatable cowl member  102  is fully translated, blocker door assembly  104  passively extends radially into bypass duct  22  to block or impede fan air from flowing through outlet end  15  (shown in  FIG. 1 ) so that fan air is directed through thrust reverser assembly  100  to provide reverse thrust (i.e., full deployment of thrust reverser assembly). 
     In an exemplary embodiment, translatable cowl member  102  includes a radially inner panel  106  and a radially outer panel  108  being arranged and configured to define a space  110  therebetween. Thrust reverser assembly  100  includes an actuator assembly  112  coupled to translatable cowl member  102  and positioned at least partially within space  110  to selectively translate cowl member  102  in a generally axial direction. In the exemplary embodiment, actuator assembly  112  may be electrically, pneumatically, or hydraulically powered in order to translate cowl member  102  between the operational positions. A torque box  114  is coupled to actuator assembly  112  proximate a forward end  116  of translatable cowl member  102  and facilitates operation of actuator assembly  112 . 
     The exemplary embodiment also includes a plurality of thrust reverser members  118  positioned within space  110  between the radially inner and outer panels  106  and  108 , respectively, so as to be selectively covered and uncovered by translatable cowl member  102 . Thus, when translatable cowl member  102  is disposed in the stowed operational position, thrust reverser member  118  is covered, and when translatable cowl member  102  is in the fully translated operational position, thrust reverser member  118  is uncovered. Appropriate flow directing members and seals are utilized in the exemplary embodiments to provide a sealing (e.g., air tight) engagement among components. In an exemplary embodiment, thrust reverser members  118  are fixed cascade structures including a plurality of cascade turning vanes  120 . Furthermore, a support ring  122  is coupled to the aft ends of thrust reverser members  118  to provide support to members  118 . 
     In operation, when the translatable cowl member  102  is in the stowed operational position ( FIG. 3 ), air in bypass duct  22  is generally directed out outlet end  15  in a forward thrust operation. To provide reverse thrust, the translatable cowl member  102  is moved into the fully translated operational position ( FIG. 4 ) whereby thrust reverser members  118  are uncovered and airflow is directed through turning vanes  120 . 
     With particular reference to  FIGS. 3 and 4 , blocker door assembly  104  includes a base  124  coupled to outer wall  23  and a drag link  126  coupled to base  124  and extending through bypass duct  22 . In the exemplary embodiment, blocker door assembly  104  also includes a blocker door  128  pivotally coupled to both drag link  126  and inner panel  106  of cowl member  102 . Blocker door  128  is operable to move radially by turning about a hinge  129  when acted upon by sufficient air load when thrust reverser assembly  100  is fully deployed and the engine power and airflow is increased. As illustrated in  FIG. 4  in an exemplary manner, blocker door  128  cooperates with outer wall  23  to block or impede airflow through bypass duct  22 , and instead the airflow is directed through the thrust reverser assembly  100  and is turned by turning vanes  120  to provide reverse thrust. Thus, blocker door  128  is passively activated (e.g., by airflow) rather than being actively rotated by a mechanical actuator or other mechanism. Alternatively, blocker door  128  is actively controlled by a mechanical actuator or other mechanism. 
       FIG. 5  is a perspective view of blocker door assembly  104  for use with the thrust reverser assembly shown in  FIG. 3 ,  FIG. 6  is a top view of a body portion  130  of blocker door  128 , and  FIG. 7  is a bottom view of body portion  130 . . In the exemplary implementation, blocker door  128  includes a body portion  130 , a plurality of mounting structures  132 , and a facesheet  134 . More specifically, body portion  130  is molded from a thermoplastic material such that body portion  130  is integrally formed with mounting structures  132 . Molding of the thermoplastic material may be done by either injection molding or compression molding. In another implementation, any thermoplastic material molding process may be used to integrally form body portion  130  and mounting structures  132 . In the exemplary implementation, the thermoplastic material includes at least one of polyetherether ketone, polyether sulfone, polyetherkeytone keytone, polyphenylsulfone, polyphenylene sulfide and polyetherimide. In another implementation, the thermoplastic material includes any high temperature tolerant and chemically tolerant resin. 
     In the exemplary implementation, body portion  130  includes a backsheet  136  that is integrally formed, or co-molded, with a honeycomb core  137  from the thermoplastic material. More specifically, thermoplastic material is injection molded or compression molded to form backsheet  136  and honeycomb core  137 . As described in further detail below, the use of thermoplastic materials allows both the cell wall height and thickness of honeycomb core  137  to be customized to meet desired specification. Furthermore, different portions of the honeycomb body portion may have different cell sizes to account for different loading or noise attenuation requirements. Such customization of the honeycomb cell size enables increased noise attenuation. Accordingly, mounting structures  132 , backsheet  136 , and honeycomb core  137  are all concurrently and integrally molded from the thermoplastic material. 
     As shown in  FIG. 7 , body portion  130  includes backsheet  136  integrally formed with honeycomb core  137 . In the exemplary implementation, core  137  includes a plurality of cells  170  that include a plurality of walls  172  to form each cell  170 . As described above, core  137  is customizable such that the thickness and height of walls  172  changes based on their location on body  130 . More specifically, each set of cells  170  is defined by walls  172  having a predetermined thickness that is different from a wall thickness of every other set of cells. 
     In the exemplary implementation, plurality of cells  170  includes a first set of cells  174  that are defined by a first set of walls  176 , a second set of cells  178  that are defined by a second set of walls  180 , a third set of cells  182  that are defined by a third set of walls  184 , and a fourth set of cells  186  that are defined by a fourth set of walls  188 . More specifically, walls  176  of first set  174  include a first thickness T 1  that is larger than a thickness T 2  of walls  180  of second set  178 . Similarly, walls  184  of third set  182  include a third thickness T 3  that is smaller than thicknesses T 1  and T 2 , but larger than a thickness T 4  of walls  188  of fourth set  186 . Although body portion  130  is shown as having four sets of cells  170  and walls  172 , body portion  130  may have greater or fewer sets of cells  170  and walls  172 . Generally, body portion  130  includes any number of sets of cells  170  and corresponding walls  172  as desired to facilitate operation of body portion  130  as described herein. 
     Body portion  130  also includes a plurality of stiffening ribs  190  that are integrally formed, or co-molded, with honeycomb core  137  and backsheet  136  to provide additional strength to body portion  130 . Ribs  190  extend from backsheet  136  towards a distal end of walls  172 . More specifically, ribs  190  extend a first distance from backsheet  136  and walls  172  extend a second distance that is larger than the first distance such that cells  170  are taller than ribs  190 . In one implementation, ribs  190  includes a pair of ribs  190  that extend from a center area  192  of core  137  toward a corner of body portion  130 . The pair of ribs  190  is parallel to one another to further strengthen body portion  130 . Furthermore, ribs  190  extend adjacent to cell sets  174  and  178  having the thickest walls  176  and  180  such that the close positional relationship of ribs  190  and thick walls  176  and  180  provide a concentrated area of strength to body portion  130 . 
       FIG. 8  is a cross-sectional side view of blocker door  128  for use with blocker door assembly  104 , and  FIG. 9  is an exploded view of blocker door  128 . In another implementation, backsheet  136  is a solid laminate structure over which thermoplastic material is injection molded or compression molded to form mounting structures  132  and body portion  130  around laminate backsheet  136 . As such, mounting structures  132  are co-molded with body portion  130  such that mounting structures  132  and body portion  130  are integrally formed. In another implementation, mounting structures  132  are coupled to thermoplastic body portion  130  after formation of body portion  130 . Additionally, machining of integrally-formed mounting structures  132 , such as drilling of at least one through-hole  138 , may be completed after forming body portion  130  about mounting structures  132 . 
     In the exemplary implementation, facesheet  134  is coupled to an inner surface  140  of body portion  130  such that facesheet  134  is exposed to bypass duct  22  (shown in  FIG. 4 ). In the exemplary implementation, facesheet  134  is formed from the same thermoplastic material as body portion  130 . In another implementation, facesheet  134  is formed from a thermoplastic material different from the thermoplastic material that forms body portion  130 . In yet another implementation, facesheet  134  is formed from a plurality of plies  142  of material. More specifically, facesheet  134  is formed from between approximately 3 and approximately 20 plies  142  that are compression molded together. The plurality of plies  142  may be thermoplastic material or may be a composite thermoplastic material, such as, but not limited to carbon fiber, or may be a thermoset material. 
     Furthermore, in the exemplary implementation, facesheet  134  includes a plurality of openings  144  (as shown in  FIG. 9 ) formed therethrough. Openings  144  facilitate attenuating noise generated within engine  10  to reduce the amount of noise that escapes engine  10 . In the exemplary implementation, each opening  144  includes a dimension of between approximately 0.02 inches (in.) and 0.06 in. More specifically, each opening  144  includes a dimension of approximately 0.04 in. In another embodiment, openings  144  include any dimension size that facilitates operation of blocker door  128  of blocker door assembly  104  as described herein. Additionally, openings  144  may be any shape, such as but not limited to, circular, elliptical, or rectangular that facilitates operation of blocker door  128  of blocker door assembly  104  as described herein. In the exemplary implementation, openings  144  are either co-formed with facesheet  134  via hot needle perforation or drilled (via gang-drilling or punch drilling) after formation of facesheet  134 . 
     As described herein, in the exemplary implementation, facesheet  134  is coupled to body portion  130  using a thermal bonding process. Such thermal bonding thermally welds body portion  130  to facesheet  134  such that body portion  130  and facesheet  134  form an integral, single-piece component. In another implementation, facesheet  134  is coupled to body portion  130  using adhesive bonding. In yet another implementation, blocker door  128  includes a plurality of mechanical fasteners  146  that facilitate coupling facesheet  134  to body portion  130 . Any combination of thermal bonding, adhesive bonding, and fasteners  146  may be used to couple facesheet  134  to body portion  130 . 
     In one implementation, body portion  130  includes a first portion  148  and a second portion  150 . In such configurations, blocker door  128  includes an intermediate sheet  152  coupled between first portion  148  and second portion  150 . In the exemplary implementation, intermediate sheet  152  is formed from the same thermoplastic material as body portion  130 . In another implementation, intermediate sheet  152  is formed from a thermoplastic material different from the thermoplastic material that forms body portion  130 . In another implementation, intermediate sheet  152  is formed from a thin sheet of fabric. Intermediate sheet  152  includes a plurality of raised protrusions  154  that correspond to a plurality of recess  156  formed in body portion  130 . Protrusions  154  of intermediate sheet  152 , when combined with recesses  156  of body portions  148  and  150 , facilitate attenuating noise generated within engine  10  to reduce the amount of noise that escapes engine  10 . In another implementation, intermediate sheet  152  does not include protrusion  154  and is substantially flat. In the exemplary implementation, intermediate sheet  152  includes a thickness of between approximately 0.002 in. and 0.008 in. More specifically, intermediate sheet  152  includes a thickness of approximately 0.005 in. In another embodiment, intermediate sheet  152  includes any thickness that facilitates operation of blocker door  128  of blocker door assembly  104  as described herein. 
     As described above with respect to facesheet  134  and body portion  130 , intermediate sheet  152  is coupled between first and second portions  148  and  150  of body portion  130  using a thermal bonding process. Such thermal bonding thermally welds intermediate sheet  152  between first and second portions  148  and  150  such that first and second portions  148  and  150 , intermediate sheet  152 , and facesheet  134  form an integral, single-piece component. In another implementation, intermediate sheet  152  is coupled between first and second portions  148  and  150  using adhesive bonding. In yet another implementation, mechanical fasteners  146  facilitate coupling intermediate sheet  152  between first and second portions  148  and  150 . Any combination of thermal bonding, adhesive bonding, and fasteners  146  may be used to couple intermediate sheet  152  between first and second portions  148  and  150  of body portion  130 . 
     In one implementation, blocker door  128  also includes a sealing element  158  (shown in  FIG. 5 ) coupled about at least a portion of a perimeter of body portion  130 . Sealing element  158  forms a seal between blocker door  128  and at least one of inner panel  106  of translating cowl assembly  102  (both shown in  FIG. 3 ) and an inner panel  160  of torque box  114  (both shown in  FIG. 3 ). As such, sealing element  158  prevents, or reduces, air from flowing from bypass duct  22  through translating cowl assembly  102  when blocker door assembly  104  is not deployed, as shown in  FIG. 3 . 
       FIG. 10  is a flow chart illustrating an exemplary method  300  of manufacturing blocker door  128 . Method  300  includes forming  302  a facesheet, such as facesheet  134 , from at least one of a thermoplastic material and a composite material and  15 - 1039 -US-CNT ( 24691 - 1088 ) forming  304  a body portion, such as body portion  130 , from a thermoplastic material using one of injection molding, compression molding, or another thermoplastic molding process. In one implementation, forming  304  includes forming integrally forming a honeycomb core, such as core  137 , and a backsheet, such as backsheet  136  from the thermoplastic material. Method  300  further includes coupling  308  the facesheet to the body portion using at least one of thermal bonding, adhesive bonding, and a plurality of mechanical fasteners. 
       FIG. 11  is a perspective view of a compression molding assembly  200  that may be used to compression mold body portion  130  (shown in  FIGS. 6 and 7 ) of blocker door  128  (shown in  FIG. 5 ). More specifically, assembly  200  is used to integrally form backsheet  136  and honeycomb core  137 . In the exemplary implementation, assembly  200  includes a ram assembly  202  and a lower forming assembly  204  that combine to compression mold body portion  130  from thermoplastic material in a single piece. 
       FIG. 12  is a side view of compression molding assembly  200  prior to molding of blocker door body portion  130 , and  FIG. 13  is a side view of compression molding assembly  200  after molding of blocker door body portion  130 . As shown in  FIGS. 12 and 13 , ram assembly  202  includes a ram plate  206  including a lower surface  208  that defines the profile of body portion  130 . Ram plate  206  also includes a plurality of heating channels  210  and a plurality of cooling channels  212  alternatingly-spaced across ram plate  206 . Channels  210  and  212  are configured to either bring heat to or remove heat from a thermoplastic material  214  during molding to facilitate melting material  214  for molding or curing material  214  after molding. A plurality of thermocouples  216  are also housed within ram plate  206  to measure the temperature of ram plate  206  and/or material  214 . 
     In the exemplary implementation, ram plate  206  also includes a plurality of openings  218  defined therethrough. Openings  218  are defined in surface  208  and extend through ram plate  206  perpendicular to channels  210  and  212 . Ram assembly  202  further includes a plurality of core inserts  220  removably coupled to ram plate  206  such that each opening  218  receives a respective one of core inserts  220 . As described herein, core inserts  220  are removably coupled with a respective opening  218  of the plurality of openings  218  and facilitate forming honeycomb core  137  of the blocker door body portion  130 . More specifically, each core insert  220  forms a respective cell  170  (shown in  FIG. 7 ) of plurality of cells  170  and the gap (not shown in  FIG. 12 or 13 ) between adjacent core inserts  220  form a respective wall  172  (shown in  FIG. 7 ) of plurality of walls  172 . 
     Ram assembly  202  also includes a plurality of guide posts  222  that guide ram plate  206  towards lower forming assembly  204  during molding. As described in further detail herein, lower forming assembly  204  includes a plurality of sidewalls  224  and a forming plate  226  that combine to define a cavity (not shown in  FIG. 12 or 13 ) in which material  214  is loaded for molding. Forming plate  226  also includes a plurality of heating channels  228  and a plurality of alternatingly-spaced cooling channels  230 . As in ram plate  206 , channels  228  and  230  are configured to either bring heat to or remove heat from a thermoplastic material  214  during molding to facilitate melting material  214  for molding or curing material  214  after molding. A plurality of thermocouples  232  are also housed within forming plate  226  to measure the temperature of forming plate  226  and/or material  214 . 
       FIG. 14  is a perspective bottom view of ram assembly  202  illustrating ram plate  206  and core inserts  220 .  FIGS. 15 and 16  are perspective cross-sectional views ramp plate  206 , core inserts  220 , and forming plate  226 . In the exemplary implementation, core inserts  220  includes a plurality of sets of core inserts, wherein each set of core inserts  220  is a different size than every other set of core inserts  220 . More specifically, as shown in  FIG. 14 , ram assembly  202  includes a first set  234  of inserts  220 , a second set  236  of inserts  220 , a third set  238  of inserts  220 , and a fourth set  240  of inserts  220 . Each set  234 ,  236 ,  238 , and  240  is different in size than every other set  234 ,  236 ,  238 , and  240 . For example, first set  234  includes a first size of inserts  220  and second set  236  includes a second size of inserts  220  that is different than the first size. Although ram assembly  202  is shown as having four sets of inserts  220 , ram assembly  202  may have greater or fewer sets of inserts  220 . Generally, ram assembly  202  includes any number of sets of inserts  220  as desired to facilitate operation of ram assembly  202  as described herein. 
     In the exemplary implementation, each insert  220  is removable coupled to ram plate  206  such that each insert is interchangeable to facilitate tailoring the size of cells  170  in body portion  130  to meet desired strength requirements of body portion  130 . More specifically, smaller inserts  220  may be coupled to ram plate  206  in an area where increased strength is desired in body portion  130 . Because gaps between adjacent inserts  220  define a thickness of walls  172  of honeycomb core cells  170 , the smaller the inserts  220 , the larger the wall thickness, and thus the increase in strength in that region of body portion  130 . Similarly, in areas where an increased strength is not required, larger inserts  220  can be used to decrease the wall thickness and, thus, decrease the weight of body portion  130 . As such, the wall thickness of each cell  170  of honeycomb core  137  is able to be tailored based on the size of the insert  220  used for that cell  170 , wherein the size of insert  220  is based on a desired load capacity at the location of that cell  170  in core  137 . 
     As shown in  FIGS. 15 and 16 , each core inserts  220  is coupled to ram plate  206  using one of a plurality of removable fasteners  242 . In the exemplary implementation, fasteners  242  are inserted through opening  218  and into an opening  244  defined in core insert  220 . Opening  244  and a portion of fastener  242  are threaded to facilitate coupling. An optional indexing pin  246  is coupled between each core insert  220  and ram plate  206  to facilitate insertion of core insert in the proper orientation. Additionally, opening  244  includes a keyhole  248  configured to receive a key  250  to prevent rotation of core insert  220 . 
       FIG. 17  is a perspective view of an ejector assembly  252  that may be used with compression molding assembly  200  to eject molded blocker door body portion  130  from ram assembly  202 . In the exemplary implementation, ejector assembly  252  includes an ejector plate  254  and an ejector retainer plate  256  coupled to both ejector plate  254  and to ram plate  206 . A plurality of ejector control plates  258  are coupled to ejector plate  254  and facilitate movement of ejector assembly  252  and ram assembly  202  toward lower forming assembly  204 . Ejector assembly  252  also includes a plurality of ejector pins  260  that extend through a plurality of pin openings  262  (shown in  FIG. 14 ) formed in ram plate  206 . In operation, as ram assembly  202  is moved away from lower forming assembly  204 , fully formed body portion  130  is also lifted therewith. Ejector assembly  252  may either then be lowered toward ram assembly  202  or held stationary and ram assembly  202  moved toward ejector assembly  252  to eject body portion  130  from ram assembly  202 . Plates  254  and  256  include guide post openings  264  to allow ejector assembly  252  to move along guide posts  222 . As ram assembly  202  and ejector assembly  252  come together, ejector pins  260  extend through pin openings  262  in ram plate  206  and detach body portion  130  from ram plate  206 . 
       FIG. 18  is a perspective view of lower forming assembly  204  illustrating sidewalls  224  coupled to forming plate  226 . In the exemplary implementation, sidewalls  224  and forming plate  226  form a cavity  266  in which thermoplastic material  214  is loaded to mold blocker door body potion  130 . Sidewalls  224  form the perimeter of body portion  130  and are removable and interchangeable to enable different sidewalls  224  to be used based on a desired property of body portion  130 . For example, if a specific feature is desired along a portion of the perimeter of body portion  130 , then a sidewall  224  having the desired feature may be positioned in lower forming assembly  204 . Then, when the feature is no longer desired, the original sidewall  224  may be positioned in assembly  204 . Alternatively, the desired featured may be machined into one or more sidewalls  224  and not into the remaining sidewalls  224 , then the machined sidewall  224  may be returned to assembly  204 . 
       FIG. 19  is a bottom perspective view of lower forming assembly  204  illustrating a plurality of removable mounting structure inserts  268 . Each mounting structure insert  268  forms a mounting structure  132  on body portion  130  and is inserted through a corresponding opening  270  in forming plate  226 . Mounting structure inserts  268  form at least one of a hinge structure or a draglink structure on body portion  130 . Alternatively, a mounting structure  268  may be used that doesn&#39;t form a structure on body portion  130 . Similar to sidewalls  224 , mounting structure inserts  268  are removable and interchangeable to enable different mounting structure inserts  268  to be used based on a desired mounting structure of body portion  130 . Furthermore, mounting structure inserts  268  are modular to enable each insert  268  to change shape to form a different mounting structure  132  based on a predetermined desired mounting structure  132  without having to change other components of compression molding assembly  200 . 
       FIG. 20  is a flow chart illustrating an exemplary method  400  of forming body portion  130  of blocker door  128  using compression molding assembly  200 . As described above, body portion  130  includes honeycomb core  137  including plurality of cells  170  defined by a plurality of walls  172 . Method  400  includes coupling  402  the plurality of removable core inserts  220  to ram plate  206  of compression molding assembly  200 . More specifically, coupling  402  core inserts  220  includes coupling  402  the plurality of sets  234 ,  236 ,  238 , and  240  of core inserts  220 , wherein each set of core inserts is a different size than every other set of core inserts. For example, the coupling  402  step includes coupling a first set  234  of core inserts to ram plate  206 , wherein first set  234  of core inserts are a first size, and coupling  402  a second set  236  of core inserts to ram plate  206 , wherein second set  236  of core inserts are a second size that is different from the first size. 
     Method  400  also includes loading  404  thermoplastic material  214  into compression molding assembly  200 . More specifically, material  214  is loaded  404  into cavity  266  formed by sidewalls  224  and forming plate  226  of lower forming assembly  204 . Ram plate  206  is then compressed  404  toward forming assembly  204  into the thermoplastic material  214 , and the plurality of cells  170  of honeycomb core  137  are then formed  408  using the plurality of core inserts  220 . Forming  408  the plurality of  15 - 1039 -US-CNT ( 24691 - 1088 ) cells  170  includes forming a first set of cells  174  with a first set  234  of core inserts  220  of the plurality of core inserts and forming a second set  178  of cells with a second set  236  of core inserts  220  of the plurality of core inserts. 
     The embodiments herein describe a blocker door assembly for use in a gas turbine engine. The blocker door assembly includes a facesheet including a plurality of openings to facilitate noise attenuation and a body portion coupled to the facesheet. The body portion includes a backsheet integrally formed with a honeycomb core, wherein the body portion is molded from a thermoplastic material using one of injection molding, compression molding, or another thermoplastic molding process. Also described herein is a compression molding assembly for molding the honeycomb core of the blocker door, wherein the honeycomb core includes a plurality of cells defined by a plurality of walls. The compression molding assembly includes a ram plate including a plurality of openings defined therethrough and a plurality of core inserts coupled to the ram plate. The core inserts are configured to form the honeycomb core of the blocker door. Each core insert is removably coupled with a respective opening of the plurality of openings in the ram plate such that each core insert is configured to form a respective cell of the plurality of cells. 
     As described herein, the integrally formed thermoplastic blocker door has a number of advantages over conventional blocker doors made from different materials that are coupled together. For example, conventional blocker doors are fabricated from upper and lower skins that surround an aluminum honeycomb core coupled to the skins by an adhesive. The aluminum honeycomb core often includes standardized cell height and wall thickness. A portion of the honeycomb core may be filled in with a potting compound to enable the honeycomb core to sustain higher loads if the standardized sizes do not meet specifications. However, in addition to increasing the weight of the blocker door, the potting compound has an undesirable effect on the sound attenuation characteristics of the aluminum honeycomb core. The use of molded thermoplastic avoids the constraints of utilizing standard sized honeycomb and also avoids the use of the potting material filling of the honeycomb because the cell height and wall thickness can be customized to meet desired specification. 
     Furthermore, the removable individual core inserts enable different portions of the honeycomb body portion to have different cell sizes to account for different loading or noise attenuation requirements. Such customization of the honeycomb cell size allows for increased loading on body portion. Additionally, the use of thermoplastic materials to replace aluminum skin and honeycomb results in both a reduced weight of the blocker door and lower cost due to reduced material and labor costs. 
     Furthermore, each core insert is removably coupled to the ram plate such that each core insert is interchangeable to facilitate tailoring the size of honeycomb cells in the body portion to meet desired strength requirements. More specifically, smaller core insert may be coupled to the ram plate in an area where an increased strength is desired in the body portion. Because gaps between adjacent core insert define a wall thickness of honeycomb core cells, a smaller core insert leads to a larger wall thickness, which increases strength in that region of the body portion. Similarly, in areas where an increased strength is not required, a larger core insert can be used to decrease the wall thickness and, thus, decrease the weight of the body portion. As such, the wall thickness of each cell of the honeycomb core is able to be tailored based on the size of the core insert used for that cell, wherein the size of core insert is based on a desired load capacity at the location of the cell in the honeycomb core. 
     This written description uses examples to disclose various implementations, including the best mode, and also to enable any person skilled in the art to practice the various implementations, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.