Field of the Invention
The present invention relates generally to the field of aircraft and more particularly to an auxiliary inlet for a jet engine.
Background of the Invention
Auxiliary inlets for jet engines are used to increase the air flow capture area of the inlet at high angles of attack and low air speed situations. Present auxiliary inlets are usually trap doors that have hinges that create turbulence, limiting aircraft performance. In addition, present auxiliary inlets are open on the sides which allows air to spill out the sides. This limits the effectiveness of the auxiliary inlet.
Thus there exists a need for an auxiliary inlet that does not have a hinge that creates turbulence and which does not have open sides.
Summary of the Invention
An auxiliary inlet for a jet engine that overcomes these and other problems has a first rod block attached to a first side of a hole in a skin of an inlet of the jet engine. A second rod block is attached to an opposing side of the hole in the skin of the inlet of the jet engine. A first reinforced elastomer section is attached to the first rod block. A center beam has a first side attached to the first reinforced elastomer section. A second reinforced elastomer section is attached to the second rod block and attached to the center beam. An actuation system is connected to an intake end of the center beam. The actuation system moves the center beam from a first in-moldline position to a second out-of-moldline position.
Brief Description of the Drawings
FIG. 1 is a partial perspective view of an aircraft having an auxiliary inlet for a jet engine in accordance with one embodiment of the invention;
FIG. 2 is a schematic diagram of an auxiliary inlet for a jet engine in accordance with one embodiment of the invention;
FIG. 3 is a schematic diagram of an auxiliary inlet for a jet engine in accordance with one embodiment of the invention;
FIG. 4 is a cross sectional view of an auxiliary inlet for a jet engine in accordance with one embodiment of the invention;
FIG. 5 is a top view of an auxiliary inlet for a jet engine in accordance with one embodiment of the invention;
FIG. 6 is a cross sectional view of an auxiliary inlet for a jet engine in accordance with one embodiment of the invention;
FIG. 7 is a partial top view of an auxiliary inlet of FIG. 6; and
FIG. 8 is a perspective view of a reinforced elastomer panel.
Detailed Description of the Drawings
FIG. 1 is a partial perspective view of an aircraft 20 having an auxiliary inlet 22 for a jet engine in accordance with one embodiment of the invention. The auxiliary inlet 22 is mounted on the inlet 24 and together they form an intake system for the jet engine. The auxiliary inlet is shown in an expanded position (out-of-moldline position). The inlet 24 has an outer skin 26 and is attached to an intake side of the jet engine. The auxiliary inlet 22 increases the quantity of air captured at high angles of attack and/or at slow speeds.
FIG. 2 is a schematic diagram of an auxiliary inlet 40 for a jet engine in accordance with one embodiment of the invention. In this embodiment the auxiliary inlet 40 extends outside the inlet's 42 moldline. Additional air is scooped into the inlet 42 by this embodiment of the auxiliary inlet 40. FIG. 3 is a is a schematic diagram of an auxiliary inlet 50 for a jet engine in accordance with one embodiment of the invention. In this embodiment the auxiliary inlet 50 extends inside of the inlet's 52 moldline. Each inlet design has its advantages and disadvantages.
FIG. 4 is a cross sectional view of an auxiliary inlet 60 for a jet engine in accordance with one embodiment of the invention. The auxiliary inlet 60 has a first rod block 62 attached to a first side of a hole 66 in a skin 68 of the inlet of the jet engine. A first reinforced elastomer section 70 is attached to the first rod block 62 and a first center rod block 72. The function and operation of the rod blocks 62, 72 and the reinforced elastomer section 70 will be described in more detail with respect to FIG. 8. A center beam 74 is attached to the first center rod block 72 and attached to a second center rod block 76. A second reinforced elastomer section 78 is attached to the second center rod block 76 and the second rod block 80. The second rod block 80 is connected to an opposing side 82 of the hole 66. A pair of six bar hinges 84, 86 connect the center beam 74 to the inlet. The first one of the pair of six bar hinges 84 is connected between the first side (one side) 64 of the perimeter of the hole 66 and the center beam 74 or first center rod block 72. The second one of the pair of six bar hinges 86 is connected between the opposing side 82 of the hole 66 and the center beam 74 or the second center rod block 76. An actuation system 88, 90 moves the auxiliary inlet 60 from a first in-moldline position to a second out-of-moldline position. The reinforced elastomer sections 70, 78 form smooth curvilinear surfaces throughout the operating range of the auxiliary inlet 60. This provides closed side surfaces for the auxiliary inlet 60 that do not allow the air to spill out the sides and provides a smooth surface to reduce turbulence.
FIG. 5 is a top view of an auxiliary inlet 60 for a jet engine in accordance with one embodiment of the invention. This view shows an intake side 100 of the auxiliary inlet 60 and the closed side 102 of the auxiliary inlet 60. A third rod block 104 is attached to the closed side 102 of the auxiliary inlet 60. A third reinforced elastomer section is attached to the third rod block 104 and attached to a closed end of the second reinforced elastomer section. The third reinforced elastomer section includes a first subsection 106 having a plurality of crossed reinforcing rods. A first strut 108 is connected between the first rod block 62 and the center beam 74 and adjacent to a first side of the first subsection 106. The strut 108 is a flexible material such as a composite, but is more rigid than the elastomer. The first strut 108 provides stability at the junction between the first reinforced elastomer section 70 and the first subsection 106. A second strut 110 is connected between the third rod block 104 and the center beam 74. The second strut 110 is adjacent to a second side of the first subsection 106. A middle subsection 112 has a plurality of parallel reinforcing rods running between the center beam 74 and the third rod block 104. A third strut 114 is attached between the third rod block 104 and the center beam 74. The third strut 114 is attached to a second side of the middle subsection 112. A fourth strut 116 is attached between the second rod block 80 and the center beam 74. A second subsection 118 has a plurality of crossed reinforcing rods. The second subsection 118 is attached to the third strut 114 and the fourth strut 116. The third elastomer section provides a smooth curvilinear transition from the closed end 102 to the center beam 74. This requires the first and second subsections 106, 118 to bend and twist. As a result, these sections have the crossed reinforcing rods. This results in the auxiliary inlet not having any hinges that create turbulence.
FIG. 6 is a cross sectional view of an auxiliary inlet 120 for a jet engine in accordance with one embodiment of the invention. This view shows a center beam 122 attached to a pair of reinforced elastomer sections 124, 126. The reinforced elastomer sections 124, 126 are attached to rod blocks 128, 130. A linear actuator 132 is connected to the center beam 122. FIG. 7 is a partial top view of the auxiliary inlet 120 of FIG. 6.
FIG. 8 is a perspective view of a reinforced elastomer panel 150. The elastomer panel 150 has a rod block 152 attached along one edge to an elastomer skin 154. The elastomer skin 154 is capable of stretching to 100% of its unstressed length. In addition, the elastomer skin 154 is capable of twisting. A plurality of rods 156 are attached to the rod block 152 and are allowed to slide freely inside the elastomer skin 154. The rods 156 are made from quartz, epoxy or composites and flex without breaking. The stiffness of these reinforcements is designed to yield a specific expanded shape. The rods 156 slide freely inside a second rod block 158. The rods 156 provide the elastomer skin (elastomer sheet) 154 with a smooth curvilinear shape when the elastomer panel 150 is elongated, deflected or twisted. This curvilinear shape provides a good aerodynamic shape without any discontinuities that cause turbulence and drag. A plurality of attachment provisions 160 are used to attach the elastomer panel 150 to the aircraft. In the first subsection 106 and second subsection 118 the reinforcing rods run both lengthwise and widthwise. Both sets of reinforcing rods are attached at one end and slide freely through the other side. Whether the rods slide through the rod block 104 (108) or the struts 108 (110), is a design choice.
Thus there has been described an auxiliary inlet for an aircraft that does not have a hinge that creates turbulence and which does not have open sides.
While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alterations, modifications, and variations in the appended claims.