Carrier having body with nose section

Abstract

A vehicle has a body extending between a nose section and a tail section. The nose section terminates in a tip. The body has a centerline axis extending from the tip. The nose section has an outer wall terminating in a tip. The outer wall includes an outer wall centerline axis, an inner surface, and an outer surface.

Description

[0001] Government funded research

[0002] The project leading to this application has received funding from the Defense Advanced Research Projects Agency under Grant Contract No. FA8650-20-C-7011. Technical Field

[0003] The present invention generally relates to a vehicle having a body with a nose section, and more particularly to the geometry of the nose section. Background Art

[0004] Some vehicles (e.g., aircraft) include a body extending between a nose and a tail, and at least two wings extending from the body. The aircraft may include one or more engines mounted to the wings or fuselage to generate thrust. During operation of the aircraft, a streamlined airflow flows around the nose, over the wings, and eventually through the tail. In some cases, the streamlined airflow at the nose may be compressed, causing a layer of air between the nose and the streamlined airflow to be heated. In order to cope with this heating, the aircraft may utilize a cooling circuit (particularly evaporative cooling) to cool the nose. Evaporative cooling is accomplished by supplying a cooling fluid to an inner portion of the nose and discharging the cooling fluid to an outer portion of the nose through a porous material disposed along the nose. The cooling fluid on the outside of the nose then follows the streamlined airflow along the body, thereby forming a cooling fluid film on a portion of the body. The cooling fluid film effectively isolates the nose from other parts of the body, preventing thermal contact with the streamlined airflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A full and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0006] Figure 1 is a schematic perspective view of a vehicle comprising a body extending between a nose section and a tail section; and

[0007] Figure 2 is from Figure 1 Schematic cross-sectional view of a nose segment as seen along section line II-II, the nose segment terminating in a tip and comprising an outer wall having a thickness defining a flared cross-section from the tip and in a rearward direction.

[0008]

[0009] Aspects disclosed herein relate to a vehicle having a body extending between a nose section and a tail section. The nose section terminates at a tip and has an outer wall. The outer wall has a thickness that moves in a rearward direction from the tip flaring. The flared region of the nose section may also include a porous material that allows transfer of cooling fluid through the other wall of the nose section.

[0010] As used herein, the thickness or flared structure of the nose section will be referred to as the geometry of the nose section, and the inclusion of porous material will be referred to as the composition of the nose section.The geometry and composition of the nose section allow for increased efficiency when cooling the nose section by evaporative cooling.

[0011] For the purpose of illustration, the present disclosure will be described with respect to the nose section of a vehicle, particularly a supersonic vehicle or a hypersonic vehicle. As used herein, the term "supersonic", "supersonic aircraft" or its iterations refers to an aircraft that can fly at a speed exceeding or equal to the speed of sound (e.g., greater than or equal to Mach 1). As used herein, the term "hypersonic", "hypersonic aircraft" or its iterations refers to a supersonic vehicle that travels much faster than the speed of sound (particularly greater than or equal to Mach 5). However, it should be understood that the aspects of the present disclosure described herein are not limited thereto and may have general applicability in any suitable vehicle. For example, the present disclosure may be applicable to the nose section in an aircraft. For example, the present disclosure may be used to provide benefits in industrial, commercial, and residential applications.

[0012] As used herein, the term "upstream" refers to the direction opposite to the direction of fluid flow, while the term "downstream" refers to the direction in the same direction as the direction of fluid flow. The terms "forward" or "front" mean in front of something, and "rearward" or "rear" mean behind something.

[0013] Additionally, as used herein, the term "radial" or "radially" refers to directions away from a common center. For example, in the overall context of a turbine engine, radial refers to directions along a ray extending between a central longitudinal axis of the engine and an outer periphery of the engine.

[0014] As used herein, the term "set" or "a group of" elements may be any number of elements, including only one.

[0015] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, rearward, etc.) are used only for identification purposes to assist the reader in understanding the present disclosure and do not create limitations, especially with respect to the position, orientation, or use of the aspects of the disclosure described herein.

[0016] Unless otherwise indicated, connection references (e.g., attach, couple, secure, fasten, connect, and join) are to be interpreted broadly and may include intermediate members between a collection of elements and relative movement between elements. Thus, connection references do not necessarily mean that two elements are directly connected and fixed relative to each other. The exemplary drawings are for illustrative purposes only, and the sizes, positions, orders, and relative sizes reflected in the attached drawings may vary.

[0017] In certain exemplary embodiments of the present disclosure, a vehicle having a nose section is provided. During operation of the vehicle, a streamlined airflow may flow against a portion of the nose section of the vehicle. The streamlined airflow flowing against the nose section may have kinetic energy. The kinetic energy is converted into internal energy in the form of heat and transferred to the nose section. The faster the vehicle travels, the higher the kinetic energy, and the higher the internal energy or heat transferred to the nose section. A vehicle flying at supersonic speeds will experience greater heating of the nose section than a vehicle flying at subsonic speeds.

[0018] To counteract the heating of the nose section, the vehicle comprises a cooling circuit for supplying a cooling fluid through a portion of the nose section to form a cooling fluid film along the nose section. The cooling fluid film insulates the nose section from the heat of the streamlined airflow. Compared to a supersonic vehicle travelling at less than Mach 5, a hypersonic vehicle will experience higher heating along the nose section.

[0019] The following describes the geometry and composition of the nose section, which is designed for higher speeds at higher temperatures of compressed streamlined airflow. The geometry and composition cool the nose section or isolate the nose section from the streamlined airflow. The geometry and composition can effectively reduce the amount of space and weight of the cooling circuit required to cool the nose section.

[0020] Figure 1 1 is a schematic perspective view of a vehicle 10 including a body 12 . The vehicle 10 may be any suitable vehicle, such as, but not limited to, an aircraft. The vehicle 10 may include a center of gravity 44 .

[0021] The body 12 extends between the nose section 14 and the tail section 16. The nose section 14 terminates at the tip 40. The body 12 includes a centerline axis 70 extending from the tip 40 of the nose section 14 to the tail section 16. The tip 40 defines the axially forward portion of the body 12 along the centerline axis 70. The centerline axis 70 may intersect or offset the center of gravity 44. The centerline axis 70 may be used to create an XYZ coordinate system, wherein the x-axis is parallel to the centerline axis 70. A set of wings 18 is disposed along the body 12. The set of wings 18 may be formed as part of the body 12 (e.g., the body 12 may be shaped so that the body 12 defines the set of wings 18), or the set of wings 18 may form a discrete body extending radially from the body 12. There may be any number of one or more wings in the set of wings 18. The vehicle 10 may include a set of engines 20. As shown, the set of engines 20 may be a set of turbine engines, however, any suitable engine may be envisioned. There may be any number of one or more engines in the group of engines 20 .

[0022] During operation of the vehicle 10, the set of engines 20 generates thrust to propel the vehicle 10. The set of wings 18 may include one or more additional components (eg, ailerons, rudders, elevators, etc.), not shown, to move the vehicle 10.

[0023] Figure 2 It is along Figure 1 Schematic cross-sectional view of the nose segment 14 as seen along the section line II-II of FIG. The nose segment 14 includes an outer wall 22. The outer wall 22 includes an inner surface 24 and an outer surface 26. The outer surface 26 defines the exterior surface of the nose segment 14. The outer wall 22 includes an outer wall centerline axis 96 equidistant between the inner surface 24 and the outer surface 26.

[0024] The nose interior 28 of the nose segment 14 may be at least partially defined by the inner surface 24 of the outer wall 22. As shown, the nose interior 28 may be defined by a completely hollow portion of the nose segment 14 as shown or a partially hollow portion of the nose segment 14.

[0025] The nose section 14 may include various sections defined by the material of the nose section 14. The nose section 14 may include a porous material 30. As used herein, the term "porous material" may refer to any material having a sufficiently high permeability to allow a fluid (such as, but not limited to, air, CO2, N2, steam, liquid H2O (or other liquids), lithium (or other liquid metals), or any combination thereof) to pass through the porous material 30. The porous material 30 may have any suitable porosity, such as, but not limited to, greater than or equal to 10% and less than or equal to 50%. As a non-limiting example, the porous material 30 may be, but not limited to, a high temperature metal, a high temperature ceramic, or a combination thereof. As a non-limiting example, a high temperature ceramic may include, but is not limited to, a refractory high entropy alloy, a nickel-based superalloy, TZM, C103, and the like. As a non-limiting example, a high temperature ceramic may include, but is not limited to, carbon-carbon, CMC, ultra-high temperature ceramics, and the like. The porous material 30 may be disposed along any suitable portion of the outer wall 22.

[0026] The nose section 14 may also include a non-porous material 32. The non-porous material 32 may be any suitable material that does not allow a fluid, such as air, to pass through the non-porous material 32. Conversely, the porous material 30 may allow a fluid, such as air, to pass through it. The porous material 30 may transition to the non-porous material 32 at a transition point 42. It should be understood that the porous material 30 may be disposed continuously or discontinuously within the scope of the nose section 14. As a non-limiting example, the nose section 14 may include at least a portion of the non-porous material 32 within the illustrated portion of the porous material 30.

[0027] The outer wall 22 may include a set of local positions 98 disposed along the inner surface 24. The set of local positions 98 are axially spaced apart along the inner surface 24 relative to the outer wall centerline axis 96. A straight line 90 may be drawn from a corresponding local position in the set of local positions 98 and intersect the centerline axis 70 at an angle 92. Each straight line 90 extends perpendicularly from the inner surface 24, where the local position is disposed along the inner surface 24. For purposes of illustration, three angles 92 and three straight lines 90 are shown, however, it should be understood that there may be any number of one or more angles 92 and accompanying straight lines 90. It is contemplated that the angles 92 may be used to identify the location where the local position is disposed. For example, it is contemplated that all angles 92 axially rearward of the inner surface 24 at the tip 40 may be non-zero, or otherwise include an absolute value greater than zero. In other words, the only angle 92 that is zero is the location where the inner surface 24 is located at the tip 40. It is contemplated that the angle 92 may increase axially from the tip 40 constantly or non-constantly along the outer wall centerline axis 96.

[0028] The set of local locations 98 defined by angle 92 and line 90 is used to define locations along outer wall 22 and the composition and geometry of the locations. For example, each local location defines a location along outer wall 22 having a corresponding thickness and a corresponding permeability.

[0029] As a non-limiting example, the inner surface 24 at the tip 40 has a nose thickness (t nose ) and nasal permeability (K nose ) local position. Nose thickness (t nose ) is defined as the straight-line distance between the inner surface 24 at the tip 40 and the outer surface 26 at the tip 40, wherein the straight-line distance is parallel to a straight line 90 that intersects the local position of the inner surface 24 at the tip 40.

[0030] As a non-limiting example, the outer wall 22 may include a local thickness (t local ) and local permeability (K local ). Local thickness (t local ) is defined as the straight-line distance between the inner surface 24 and the outer surface 26 at the corresponding local position, wherein the straight-line distance is parallel to the straight line 90 intersecting the corresponding local position of the inner surface 24. The local thickness (t local ) is offset from the tip 40 along the outer wall centerline axis 96.

[0031] Nose thickness (t nose ) is the minimum thickness of the nose section 14, and the local thickness (t local ) is greater than the nose thickness (t nose ). As the local thickness (t local ) is located along the outer wall centerline axis 96 toward the tip 40 (nose thickness (t nose )) moves backward or downstream, the local thickness (t local The increase in thickness behind the tip 40 along the outer wall centerline axis 96 defines the flared cross section of the outer wall 22.

[0032] Local thickness (t local ) increases linearly or non-linearly from the tip 40 along the outer wall centerline axis 96. However, it should be understood that the thickness of at least a portion of the outer wall 22 behind the tip 40 may decrease to define features along the outer wall 22, such as, but not limited to, ridges, depressions, dimples, or combinations thereof. Since the thickness of a portion of the nose segment 14 may decrease, but the thickness of the nose segment 14 still increases from the tip 40 to the rearward position of the porous material 30, it can be said that the size of the nose segment 14 increases approximately from the nose thickness (t nose ) to multiple local thicknesses (t local ) increases axially rearwardly to define a flared cross-section.

[0033] It should be appreciated that the nose section 14 may be symmetrical or asymmetrical about the centerline axis 70. As a non-limiting example, the porous material 30 may be symmetrical or asymmetrical about the centerline axis 70.

[0034] The vehicle 10 may include a cooling circuit 34 having a cooling fluid source 36 and a fluid conduit 38. The cooling fluid source 36 may be any suitable cooling fluid source, such as, but not limited to, a reservoir (e.g., a reservoir having a compressed cooling fluid), a bleed air reservoir as part of the group of engines 20, or a cooling fluid conduit 38. Figure 1 ), or any combination thereof. The cooling fluid source 36 may be disposed within any suitable portion of the vehicle 10. The fluid conduit 38 is fluidly coupled to a portion of the nose section 14. As a non-limiting example, the fluid conduit 38 is fluidly coupled directly to the nose interior 28.

[0035] During operation of the vehicle 10, a streamlined airflow (Fs) flows against the nose section 14. The streamlined airflow (Fs) includes kinetic energy as it flows against the nose section 14, which is a function of the speed of the vehicle 10. The kinetic energy of the streamlined airflow (Fs) is converted into internal energy, which is transferred to the nose section 14 in the form of heat. The conversion of the kinetic energy of the streamlined airflow (Fs) into internal energy in the form of heat will hereinafter be referred to as heating of the nose section 14. The heat transferred to the vehicle 10 is greatest at the tip 40 of the nose section 14. As the vehicle 10 moves faster, the streamlined airflow (Fs) includes more kinetic energy, and more heat is transferred to the nose section 14.

[0036] The cooling circuit 34 can selectively supply cooling fluid (Fc) from a cooling fluid source 36 to the nose segment 14 through a fluid conduit 38. The cooling fluid (Fc) flows through the nose interior 28 and impinges on corresponding portions of the inner surface 24 of the outer wall 22. The cooling fluid (Fc) flows through the porous material 30 of the outer wall 22 and flows to the outer surface 26. Once on the outer surface 26, the cooling fluid (Fc) moves with the streamlined airflow (Fs) and forms a cooling fluid (Fc) film between the streamlined airflow (Fs) and the outer surface 26 of the nose segment 14. The cooling fluid (Fc) film isolates the nose segment 14 from the streamlined airflow (Fs), ensuring that the streamlined airflow (Fs) does not overheat the nose segment 14. This movement of the cooling fluid (Fc) through the porous material 30 is a form of evaporative cooling.

[0037] As the vehicle 10 moves faster, more cooling is generally required. In the case where the vehicle 10 is a supersonic vehicle traveling at supersonic speeds, the heat generated can cause damage to the vehicle 10. In the case where the vehicle 10 is a hypersonic vehicle traveling at hypersonic speeds, the heat generated at the nose section 14 is generally greater than the heat generated at the nose section 14 of a supersonic vehicle traveling at supersonic speeds. The heat generated at the nose section 14 of a subsonic vehicle is generally negligible, and cooling may not be required.

[0038] The heating of the nose section 14 of a conventional vehicle can be characterized by a number of heat fluxes. Each section of the nose section 14 can be defined by a corresponding heat flux. The heat flux is defined as the predicted, measured, or otherwise expected flow of energy (e.g., heat) between the streamlined airflow (Fs) and the corresponding portion of the nose section 14. The nose heat flux (q nose ), and behind the tip can experience a local heat flux (q local In some cases, the nasal heat flux (q nose ) or local heat flux (q local ) may be high enough to cause damage to corresponding portions of the nose section 14 of a conventional vehicle.

[0039] In a conventional carrier (e.g., one without a flared nose section 14 or a constant permeability carrier), a thermal gradient is created between the tip 40 and locations offset from the tip 40, with the temperature being highest at the tip 40. A uniform distribution of cooling fluid does not conform to the temperature gradient. The cooling fluid distribution may adequately cool the tip 40, but locations in the nose section 14 behind the tip 40 will receive more cooling fluid than is required to adequately cool the nose section 14. The nose section 14 will be overcooled, and cooling fluid is wasted. Inefficient cooling systems typically require cooling circuits with a greater amount of space and more weight.

[0040] Due to at least one of the geometry and composition of the nose section 14, Figure 2 The cooling system effectively distributes the cooling fluid to the nose section 14. At least one of the geometry and composition of the nose section 14 can be based on the calculated, measured or modeled nose heat flux (q nose ) and local heat flux (q local ) to determine.

[0041] The geometry of the nose section 14 (eg, nose thickness (T nose ) and local thickness (t local )) and / or the composition of the nose section 14 (e.g., the nose permeability (K) of the porous material 30 nose ) and local permeability (K local)) can be changed to effectively cool the nose section 14. A cooling circuit 34 with less weight and less space can be used with an improved geometry and / or composition of the nose section 14.

[0042] Nose thickness (t nose ) and local thickness (t local ) can be calculated according to the following relationship with respect to the nose heat flux (q nose ) and local heat flux (q local ) to determine:

[0043]

[0044] Nasal permeability (K nose ) and local permeability (K local ) can be calculated according to the following relationship with respect to the nose heat flux (q nose ) and local heat flux (q local ) to determine:

[0045]

[0046] Nose heat flux (q nose ) and local heat flux (q local ) can be determined by testing, measurement, modeling, computational fluid dynamics simulation, etc. Similarly, the nose thickness (t nose ) and nasal permeability (K nose ) can be determined by modeling, simulation, real-world testing, measurement, or computational fluid dynamics simulation. As a non-limiting example, nose thickness (t nose ) and nasal permeability (K nose ) can be based on the expected nasal heat flux (q nose ) to determine.

[0047] According to the thickness of the nose (t nose ), nose heat flux (q nose ) and local heat flux (q local ) can be determined by the following relationship: local ):

[0048]

[0049] According to the nasal permeability (K nose ), nose heat flux (q nose ) and local heat flux (q local ) can be determined by the following relationship: local ):

[0050]

[0051] Further imagine that the set of local thicknesses (t local ), nose thickness (t nose ), nasal permeability (K nose ), nose heat flux (q nose ) and local heat flux (q local ) to calculate the local permeability (K local ):

[0052]

[0053] Further, it is assumed that the local permeability (K local ), nasal permeability (K nose ), nose thickness (t nose ), nose heat flux (q nose ) and local heat flux (q local ) to calculate the local thickness (t local ):

[0054]

[0055] The use of the fifth relationship (5) or the sixth relationship (6) as opposed to the fourth relationship (4) or the third relationship (3) has been found to be advantageous because the fifth relationship (5) and the sixth relationship (6) allow the local permeability (K local ) or local thickness (t local ) depends directly on the local thickness of the group (t local ) and nose thickness (t nose ), and local permeability (K local ) and nasal permeability (K nose In other words, the local permeability (K local ) can be calculated as a function of thickness, while the local thickness (t local ) can be calculated as a function of permeability. Use of relationships (5) and (6) rather than relationships (4) or (3) can further be used to illustrate the relationship between the thickness and permeability of respective portions of the nose segment 14. In other words, relationships (5) and (6) can be used to illustrate how the permeability or thickness of the nose segment 14 varies with or is otherwise dependent on the other of the permeability or thickness of the nose segment 14.

[0056] By using relationships (3), (4), (5) and (6), it has been found that selecting the geometry and composition of the nose segment 14 increases the mass flow rate of the cooling fluid (Fc) to specific locations of the nose segment 14 so that the locations of the nose segment 14 do not receive too much or too little cooling fluid (Fc).

[0057] By using relationships (3), (4), (5), and (6), it is further discovered that adjusting the geometry and composition of the nose segment 14 so that the permeability decreases while the thickness increases from the tip 40 to the rear of the tip 40 (e.g., flare), results in the maximum amount of cooling fluid (Fc) being supplied to the tip 40 where heating of the nose segment 14 is greatest, and the minimum amount of cooling fluid (Fc) being supplied to the rear of the nose segment 14 where heating is lowest.

[0058] By using the expression to select the composition and geometry of the nose section 14, it has been found that a nose section 14 with uniform cooling can be obtained. In other words, the nose section 14 has a uniform temperature during operation. In other words, during cooling, no thermal gradient is experienced across the nose section 14. Due to the uniform distribution of the cooling fluid, some parts of the nose section cool more than other sections, so conventional vehicles still experience such thermal gradients across the nose section. As described herein, eliminating thermal gradients in the nose section 14, in turn, reduces or otherwise eliminates the thermal gradients experienced across the nose section 14, which ultimately results in reduced thermal stresses across the nose section 14 compared to conventional vehicles.

[0059] It is further found that the use of the above expression to select the geometry and composition of the nose section 14 can be used to ensure optimal cooling of the nose section 14 of a supersonic vehicle (and more specifically, a hypersonic vehicle). As discussed herein, the faster the vehicle travels, the higher the heating along the nose section 14, and therefore the higher the amount of cooling required to effectively shield the heating. The expression described herein can be used to design the nose section 14 for the vehicle 10 at all suitable speeds, including supersonic and hypersonic vehicles. In other words, the expression described herein can be used to ensure that the nose section 14 of a supersonic or hypersonic vehicle is not overheated during operation of the supersonic or hypersonic vehicle. As discussed herein, the cooling of the nose section 14 of a hypersonic vehicle is particularly important compared to the cooling of the nose section of a supersonic vehicle or subsonic vehicle traveling below Mach 5, because the hypersonic vehicle will experience higher heating along the nose section 14.

[0060] To the extent not yet described, the different features and structures of the various embodiments may be used in combination or in place of one another as desired. The fact that a feature is not shown in all embodiments does not mean that it cannot be shown as such, but is done so for the sake of brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are explicitly described. All combinations or permutations of the features described herein are covered by the present disclosure.

[0061] This written description uses examples to describe the aspects of the disclosure described herein, including the best mode, and also to enable any person skilled in the art to practice aspects of the disclosure, including making and using any device or system and performing any combined methods. The patentable scope of the various aspects of the disclosure is defined by the claims, and may include other examples that occur to one skilled in the art. These other examples are intended to fall 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 that do not differ substantially from the literal language of the claims.

[0062] Further aspects are provided by the subject matter of the following clauses:

[0063] A vehicle comprising a body extending between a nose section and a tail section, the nose section terminating in a tip and the body being defined by a centerline axis extending from the tip, the nose section comprising an outer wall terminating in the tip, the tip defining an axially forward-most portion of the nose section relative to the centerline axis, the outer wall comprising an outer wall centerline axis, an inner surface and an outer surface, the outer wall having a thickness between the inner surface and the outer surface when viewed in a horizontal plane extending along the centerline axis, wherein a nose thickness (t nose ) at the tip, and the local thickness (t local ) is offset from the tip along the centerline axis of the outer wall, the local thickness (t local ) is greater than the nose thickness (t nose ).

[0064] A vehicle comprising a body extending between a nose section and a tail section, the nose section terminating in a tip and the body being defined by a centerline axis extending from the tip, the nose section comprising: an outer wall terminating in the tip, the tip defining an axially forward-most portion of the nose section relative to the centerline axis, the outer wall comprising an outer wall centerline axis, an inner surface and an outer surface, the outer wall having a thickness between the inner surface and the outer surface when viewed in a horizontal plane extending along the centerline axis; and a porous material disposed along at least a portion of the outer wall; wherein a nose permeability (K nose ) is defined by the permeability of the outer wall at the tip, and the local permeability (K local ) is defined by the permeability of the corresponding portion of the outer wall axially rearward of the tip relative to the centerline axis, the local permeability (K local ) is not equal to the nasal permeability (K nose ).

[0065] A vehicle as claimed in any preceding clause wherein the nose section comprises a flared cross section rearwardly of the tip along the outer wall centreline axis.

[0066] A vehicle according to any preceding clause, wherein the nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local thickness (t local ) is defined by the following relationship:

[0067] A carrier according to any preceding clause, wherein the local thickness (t local ) in the posterior direction from the nose thickness (t nose ) increases linearly.

[0068] A vehicle as claimed in any preceding clause, wherein the nose section further comprises a porous material disposed between the inner surface and the outer surface.

[0069] A vehicle according to any preceding clause, wherein the nose section comprises a porous material having: a nose permeability (K nose ), the nasal permeability (K nose ) is defined by the permeability of the outer wall at the tip; and the local permeability (K local ), the local permeability (K local ) is defined by the permeability of the corresponding portion of the outer wall axially rearward of the tip.

[0070] A vehicle according to any preceding clause, wherein the nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local permeability (K local ) is defined by the following relationship:

[0071] A vehicle according to any preceding clause, wherein the nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local thickness (t local ) is defined by the following relationship:

[0072] A vehicle according to any preceding clause, wherein the nose permeability (K nose ) is greater than the local permeability (K local ).

[0073] A vehicle as claimed in any preceding clause, wherein the nose section comprises a plurality of local permeabilities which are equal or unequal to one another.

[0074] A vehicle as claimed in any preceding clause wherein the outer wall defines a nose interior and the vehicle further comprises a cooling circuit at least partially defined by the nose interior and discharging through the porous material to the outer surface.

[0075] A vehicle according to any preceding clause, wherein the vehicle is a hypersonic vehicle.

[0076] A vehicle as described in any preceding clause, wherein the vehicle is a supersonic vehicle.

[0077] A vehicle according to any preceding clause, wherein the nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local permeability (K local ) is defined by the following relationship:

[0078] A vehicle according to any preceding clause, wherein the nose permeability (K nose ) is greater than the local permeability (K local ).

[0079] A vehicle according to any preceding clause, wherein the nose section comprises a thickness between the inner surface and the outer surface when viewed in the horizontal plane, and the nose section comprises: a nose thickness (t nose ), the nose thickness (t nose ) at the tip; and the local thickness (t local ), the local thickness (t local ) is axially rearward of the tip, the local thickness (t local ) is greater than the nose thickness (t nose ) such that the nose section includes a flared cross-section along the centerline axis of the outer wall.

[0080] A vehicle according to any preceding clause, wherein the nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local permeability (K local ) is defined by the following relationship:

[0081] A vehicle according to any preceding clause, wherein the vehicle is a hypersonic vehicle.

[0082] A vehicle as claimed in any preceding clause wherein the outer wall defines a nose interior and the vehicle further comprises a cooling circuit at least partially defined by the nose interior and discharging through the porous material to the outer surface.

Claims

1. A carrier, characterized in that: include: a body extending between a nose section and a tail section, the nose section terminating in a tip and defined by a centerline axis extending from the tip, the nose section comprising: an outer wall terminating at the tip, the tip defining an axially forward-most portion of the nose segment relative to the centerline axis, the outer wall comprising an outer wall centerline axis, an inner surface, and an outer surface, the outer wall having a thickness between the inner surface and the outer surface when viewed in a horizontal plane extending along the centerline axis; in: Nose thickness (t nose ) at the tip; and Local thickness (t local ) is offset from the tip along the centerline axis of the outer wall, the local thickness (t local ) is greater than the nose thickness (t nose ).

2. The carrier according to claim 1, characterized in that in, The nose section includes a flared cross-section rearward of the tip along the outer wall centerline axis.

3. The carrier according to claim 1, characterized in that in, The nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local thickness (t local ) is defined by the following relationship:

4. The carrier according to claim 1, characterized in that in, The local thickness (t local ) in the posterior direction from the nose thickness (t nose ) increases linearly.

5. The carrier according to claim 1, characterized in that in, The nose section further includes a porous material disposed between the inner surface and the outer surface.

6. The carrier according to claim 5, characterized in that in, The nose section comprises a porous material having: Nasal permeability (K nose ), the nasal permeability (K nose ) is defined by the permeability of said outer wall at said tip; as well as Local permeability (K local ), the local permeability (K local ) is defined by the permeability of the corresponding portion of the outer wall axially rearward of the tip.

7. The carrier according to claim 6, characterized in that in, The nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local permeability (K local ) is defined by the following relationship:

8. The carrier according to claim 6, characterized in that in, The nose section has a nose heat flux (q nose ), and has a local heat flux (q local ), and the local thickness (t local ) is defined by the following relationship:

9. The carrier according to claim 6, characterized in that in, The nasal permeability (K nose ) is greater than the local permeability (K local ).

10. A carrier, characterized in that: include: a body extending between a nose section and a tail section, the nose section terminating in a tip and defined by a centerline axis extending from the tip, the nose section comprising: an outer wall terminating in the tip, the tip defining an axially forward-most portion of the nose segment relative to the centerline axis, the outer wall comprising an outer wall centerline axis, an inner surface, and an outer surface, the outer wall having a thickness between the inner surface and the outer surface when viewed in a horizontal plane extending along the centerline axis; and a porous material disposed along at least a portion of the outer wall; in: Nasal permeability (K nose ) is defined by the permeability of said outer wall at said tip; and Local permeability (K local ) is defined by the permeability of the corresponding portion of the outer wall axially rearward of the tip relative to the centerline axis, the local permeability (K local ) is not equal to the nasal permeability (K nose ).

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