Patent Description:
Some known pressurized aircraft use Environmental Control Systems ("ECS") to maintain cabin pressurization and to control cabin temperatures during flight. The ECS generally channels external air from the engines towards the aircraft cabin to pressurize the cabin. Some known systems condition the air using air conditioning packs, and the conditioned air is distributed within the cabin via an air distribution system. Some air distribution systems include multiple discrete nozzles located on either side of the interior of the aircraft fuselage above the passengers. The nozzles discharge conditioned air therefrom to generate two opposing and counter-rotating "cells" of air that circulate across the passenger seats before exiting the cabin through a return air grille located at the floor of the cabin. However, generating the counter-rotating cells requires the air to be discharged at relatively high velocities, which can generate undesirable noise pollution within the cabin. In addition, the counter-rotating cells may cause cross-circulation to occur between passengers, which is a significant consideration in view of recent global health crises. <CIT>, according to its abstract, relates to an aircraft, environmental control systems, and air diffusers that may be used to create a quiet, comfortable environment within an aircraft cabin are disclosed. The air diffusers include a duct, a grille, and a porous flow conditioner positioned at least partially within an outlet plenum of the duct. The porous flow conditioner is configured to create backpressure and to reduce a velocity of air flowing out of the porous flow conditioner, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow through the air diffuser assembly, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow downstream of the porous flow conditioner. <CIT>, according to its abstract, relates to an aircraft fuselage with an upper deck, constructed as a passenger area, and a lower deck, constructed as a freight area, and with a ventilation installation for the upper deck and lower deck, wherein a bilge area is provided, which is constructed as a vacuum chamber against the freight area and connected to the freight area solely via flow orifices of small cross-section in the abutment area between a lower floor and the fuselage wall. <CIT>, according to its abstract, relates to a system for ventilating an aircraft cabin comprises an air supply pipe connected to an air source, and a plurality of air distribution lines branching off from the air supply pipe. In a first operating state, the ventilating system is adapted to blow out the air, flowing through the air supply pipe, directly from the air distribution lines into the aircraft cabin. In contrast, in a second operating state of the ventilating system, at least some of the air distribution lines are connected to connecting lines which supply the air, flowing through the air supply pipe, to air outlets arranged in a distributed manner in the aircraft cabin. <CIT>, according to its abstract, relates to an aircraft, air conditioning systems, and air diffusers that may be used to create a quiet, comfortable environment within an aircraft cabin. The systems and apparatuses are configured to flow air at a rate that meets and/or exceeds the FAA minimum requirement of <NUM> lbs/min (about <NUM>/min) per occupant. In use, even at higher flow rates, the systems and apparatuses are configured to create a quiet cabin experience, by contributing little to ambient cabin noise. Thus, the systems and apparatuses may be used to provide fresh air at a comfortable rate and a comfortable noise level. <CIT>, according to its abstract, relates to aircraft cabin airflow nozzles and associated systems and methods. A system in accordance with a particular embodiment includes a cabin air nozzle that in turn has a first passageway bounded at least in part by a first wall portion and a second wall portion spaced apart from the first wall portion. The second wall portion can have a first surface exposed to air within the first passageway, and a second surface facing away from the first surface. The first passageway can have an exit between the first and second wall portions, and the second passageway can be positioned to direct air along the second surface of the wall portion. Non patent literature document, written by <NPL>, relates according to its title to "Novel air distribution systems for commercial aircraft cabins". <CIT> is a prior art document falling under Art. <NUM>(<NUM>) EPC. According to its abstract, it states a system with an environmental control system (ECS) having a plurality of ducts configured to convey a flow of air into an interior space through the plurality of ducts. A plurality of valves are disposed in the plurality of ducts to control the flow of air through a respective duct into the interior space. A plurality of sensors are disposed in the interior space configured to sense a passenger condition.

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the disclosure, which are described and/or claimed below.

One aspect is an aircraft including a side wall at least partially defining a passenger cabin and a crown section of the aircraft. The passenger cabin includes an overhead zone, a passenger zone, and a floor zone. An air supply duct is positioned within the crown section, and the air supply duct is configured to pressurize the crown section with air. At least one return air outlet is defined in the floor zone. An interior structure is coupled to the side wall and extends between the passenger cabin and the crown section. The interior structure includes a plurality of nozzles oriented to discharge the pressurized air from the crown section along an airflow path that extends downward through the overhead zone, downward through the passenger zone, and then towards the at least one return air outlet.

Another aspect is an aircraft including a side wall at least partially defining a passenger cabin and a crown section of the aircraft. The passenger cabin includes an overhead zone, a passenger zone, and a floor zone. An air supply duct is positioned within the crown section, and the air supply duct is configured to channel air therethrough. At least one return air outlet is defined in the floor zone. A plurality of interior panels extend between the passenger cabin and the crown section, and each interior panel is coupled in flow communication with the air supply duct. The plurality of interior panels each include a plurality of perforations configured to discharge the air therefrom along an airflow path that extends downward through the overhead zone, downward through the passenger zone, and then towards the at least one return air outlet.

Yet another aspect is an air distribution system including an air supply duct configured to channel air therethrough. A plurality of interior panels are each coupled in flow communication with the air supply duct, and the plurality of interior panels are coupled to each other in an array to define an interior structure. Each interior panel includes a housing having a side wall defining an air inlet and an air outlet. A porous support structure is coupled to the side wall at the air outlet. An air plenum is defined between the air inlet and a first side of the porous support structure, and a plurality of perforations configured to discharge the air therefrom are defined on a second side of the porous support structure.

Various refinements exist of the features noted in relation to the above-mentioned aspects of the present disclosure. Further features may also be incorporated in the above-mentioned aspects of the present disclosure as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to any of the illustrated embodiments of the present disclosure may be incorporated into any of the above-described aspects of the present disclosure, alone or in any combination.

Examples described below include air distribution systems that facilitate minimizing airflow between passengers within confined spaces, such as aircraft passenger cabins. Example systems described provide a displacement ventilation scheme that generates bulk downward airflow within the confined space. In one example, the bulk downward airflow is discharged from above seated passengers in the confined space, downward past the passengers, and towards an outlet located at the floor of the confined space. This directional bulk downward airflow facilitates limiting cross-circulation between passengers seated next to each other in a respective row of an aircraft, for example. Example systems facilitate reducing the spread of airborne contaminants between nearby occupants, reducing noise and undesirable drafts, and limiting the formation of stagnant zones of circulation within the confined space.

<FIG> is a cross-sectional view of an aircraft <NUM> having an example air distribution system <NUM> therein. Aircraft <NUM> includes a fuselage <NUM> having a side wall <NUM> that at least partially defines a passenger cabin <NUM> and a crown section <NUM> of aircraft <NUM>. Crown section <NUM> is positioned above passenger cabin <NUM>, and an interior structure <NUM> coupled to side wall <NUM> extends between crown section <NUM> and passenger cabin <NUM>. Passenger cabin <NUM> includes an overhead zone <NUM>, a passenger zone <NUM>, and a floor zone <NUM>. Passenger zone <NUM> includes a plurality of seats <NUM> designed for human occupancy. Seats <NUM> are arranged in one or more rows <NUM> across passenger cabin <NUM>. Overhead zone <NUM> is located above passenger seats <NUM>, and floor zone <NUM> is located below passenger seats <NUM>.

Air distribution system <NUM> includes an air supply duct <NUM> positioned within crown section <NUM>. In one example, interior structure <NUM> is arranged such that crown section <NUM> defines an open volume between side wall <NUM> and interior structure <NUM>. Air supply duct <NUM> is configured to channel conditioned air <NUM> therethrough, which is received from an environment control system (not shown) of aircraft <NUM>. Air supply duct <NUM> is configured to discharge the conditioned air <NUM> within the crown section <NUM> to pressurize crown section <NUM> with conditioned air <NUM>. Pressurizing crown section <NUM> with conditioned air <NUM> facilitates supplying passenger cabin <NUM> with conditioned air <NUM>. For example, at least one return air outlet <NUM> is defined in floor zone <NUM> and, as will be described in more detail below, conditioned air <NUM> discharged from crown section <NUM> is channeled through passenger cabin <NUM> and then exhausted from passenger cabin <NUM> through return air outlet <NUM>. Referring to <FIG>, return air outlet <NUM> is a return air grille defined in side wall <NUM> of fuselage. Alternatively, an air exhaust port may be defined in a floor <NUM> of passenger cabin <NUM>.

Referring to <FIG>, air supply duct <NUM> includes a side wall <NUM> having a plurality of airflow openings <NUM> defined therein. Airflow openings <NUM> provide flow communication from air supply duct <NUM> to crown section <NUM> to facilitate pressurization thereof. Airflow openings <NUM> may be any size and/or shape that enables air distribution system <NUM> to function as described herein. For example, airflow openings <NUM> may be defined by multiple discrete holes or cutouts within side wall <NUM> spaced along a length of air supply duct <NUM> and fuselage <NUM>. In an alternative example, air supply duct <NUM> is a piccolo type supply duct.

Interior structure <NUM> is formed from a plurality of components, such as interior panels <NUM>, stowage bins <NUM>, overhead consoles <NUM>, and the like. In one example, at least some of components are spaced from each other to define gaps <NUM> therebetween. For example, interior panels <NUM>, stowage bins <NUM>, and overhead consoles <NUM> may be coupled to each other, but also spaced from each other to provide airflow communication between crown section <NUM> and passenger cabin <NUM> through gaps <NUM>. In such an example, a blocking member <NUM> may extend across at least one of the plurality of gaps <NUM>. Blocking member <NUM> is adapted to restrict visibility into crown section <NUM> from passenger cabin <NUM> while still permitting airflow communication therebetween. Components, such as overhead consoles <NUM>, may also be spaced from side wall <NUM> to define additional gaps <NUM>.

Accordingly, gaps <NUM> define a plurality of nozzles <NUM> within interior structure <NUM>. In an alternative example, the components themselves include airflow openings (not shown) defined therein to define nozzles <NUM> of interior structure <NUM>. For example, gaps may be hidden behind light valences or other interior features to define additional nozzles <NUM> within interior structure <NUM>. Nozzles <NUM> are designed to discharge conditioned air <NUM> therefrom in a substantially downward direction relative to crown section <NUM>. Referring to <FIG>, conditioned air <NUM> travels along an airflow path <NUM> that extends downward through overhead zone <NUM>, downward through passenger zone <NUM>, and then towards return air outlet <NUM> located in floor zone <NUM>. As a result of a combination of factors, such as airflow discharge velocity, discharge directionality of conditioned air <NUM>, and/or a pressure differential defined at return air outlet <NUM>, for example, airflow path <NUM> extends downward through passenger cabin <NUM> to facilitate limiting cross-circulation between passengers seated next to each other in a respective row <NUM> of aircraft <NUM>. As used herein, "downward" refers to a one-way direction of travel that reduces in height between two points, such as from nozzles <NUM> to return air outlet <NUM>, without the direction of travel increasing in height between the two points.

<FIG> is a cross-sectional view of aircraft <NUM> having an alternative air distribution system <NUM> therein. In the illustrated example, interior structure <NUM> includes a plurality of interior panels <NUM> extending between crown section <NUM> and passenger cabin <NUM>. Interior panels <NUM> may be ceiling panels, side wall panels, overhead console panels, and the like, which are designed to be visible and aesthetically pleasing to the occupants of passenger cabin <NUM>. Each interior panel <NUM> is coupled in flow communication with air supply duct <NUM>. For example, a branched duct <NUM> may be coupled between air supply duct <NUM> and each interior panel <NUM> to enable conditioned air <NUM> to be channeled from air supply duct <NUM> to the plurality of interior panels <NUM>. As will be described in more detail below, each interior panel <NUM> includes a plurality of perforations <NUM> (shown in <FIG>) configured to discharge conditioned air <NUM> therefrom in a substantially downward direction relative to crown section <NUM>.

As illustrated in <FIG>, conditioned air <NUM> travels along an airflow path <NUM> that extends downward through overhead zone <NUM>, downward through passenger zone <NUM>, and then towards return air outlet <NUM> located in floor zone <NUM>. Similar to airflow path <NUM>, airflow path <NUM> extends downward through passenger cabin <NUM> to facilitate limiting cross-circulation between passengers seated next to each other in a respective row <NUM> of aircraft <NUM>.

<FIG> is a cross-sectional view of an example interior panel <NUM> that may be used in air distribution system <NUM> (shown in <FIG>). In the illustrated example, each interior panel <NUM> includes a housing <NUM> having a side wall <NUM> defining an air inlet <NUM> and an air outlet <NUM>. Air inlet <NUM> is coupled in flow communication with branched duct <NUM> (shown in <FIG>) to enable conditioned air <NUM> to be channeled therethrough. Conditioned air <NUM> is channeled through housing <NUM> and then discharged from air outlet <NUM> directly into passenger cabin <NUM> (shown in <FIG>).

Interior panel <NUM> includes a nozzle <NUM> coupled to side wall <NUM> at air outlet <NUM>. In the illustrated example, nozzle <NUM> includes a porous support structure <NUM>, and at least one layer of material coupled thereto, as will be described in more detail below. Porous support structure <NUM> may be any flexible, semi-rigid, or rigid structure that enables airflow to be channeled therethrough. In the illustrated example, porous support structure <NUM> is in the form of a honeycomb structure having a plurality of hollow channels extending therethrough. Alternatively, as shown in <FIG>, an interior panel <NUM> includes porous support structure <NUM> that is in the form of a porous foam material, such as polyvinyl chloride, polyetherimide, polyvinylidene fluoride, and the like.

Nozzle <NUM> has a first side <NUM> and a second side <NUM>. Nozzle <NUM> extends across the entirety of air outlet <NUM> to define an air plenum <NUM> between air inlet <NUM> and first side <NUM> of nozzle <NUM>. Perforations <NUM> are defined on second side <NUM> of nozzle <NUM>. Extending nozzle <NUM> across air outlet <NUM> facilitates at least partially sealing housing <NUM>, which enables air plenum <NUM> to be pressurized with conditioned air <NUM> channeled through air inlet <NUM>. Accordingly, conditioned air <NUM> may be distributed across the entire surface area of first side <NUM>. In one example, air inlet <NUM> is smaller in cross-sectional size than air outlet <NUM>. Accordingly, side wall <NUM> of housing <NUM> may be tapered to increase in cross-sectional size from air inlet <NUM> to air outlet <NUM>, which facilitates equalizing the pressure of conditioned air <NUM> across first side <NUM> of nozzle <NUM>.

Referring again to <FIG>, nozzle <NUM> further includes a layer <NUM> of porous material coupled on at least one of first side <NUM> or second side <NUM> thereof. The porous material may be any material that enables interior panel <NUM> to function as described herein. For example, the porous material may be a woven fibrous material, such as in a Leno weave pattern. The woven fibrous material may also be pre-impregnated with resin, adhesive, and the like (i.e., a "prepreg" composite). Accordingly, layer <NUM> extends across first side <NUM> and/or second side <NUM> to provide support to, and increase the rigidity of, porous support structure <NUM> while still permitting airflow therethrough.

In the illustrated example, nozzle <NUM> also includes a layer <NUM> of decorative porous material coupled over layer <NUM> of porous material on second side <NUM>. Accordingly, layer <NUM> defines the exterior surface of interior panel <NUM> that is visible to occupants of passenger cabin <NUM> (shown in <FIG>). Layer <NUM> provides an improved aesthetic appearance, relative to layer <NUM>, that is suitable for visibility to occupants of passenger cabin <NUM>. The decorative porous material may be any material that enables interior panel <NUM> to function as described herein. For example, layer <NUM> may be a thermoplastic sheet perforated by laser, chemical etching, abrasive blasting, contact with a drum roller with pins, or other suitable methods. Layer <NUM> may also be a cloth fabric material. Accordingly, interior panel <NUM> is provided with a plurality of perforations <NUM> on second side <NUM> thereof. In one example, perforations <NUM> are distributed generally substantially uniformly across layer <NUM> such that conditioned air <NUM> discharged therefrom is in the form of distributed bulk airflow. Thus, airflow is provided across the exposed surface area of layer <NUM>.

In operation, conditioned air <NUM> is discharged from nozzles <NUM> and <NUM> at a flow rate greater than a first threshold, and at a velocity less than a second threshold, in order to satisfy a desired airflow recirculation rate through passenger cabin <NUM>. The flow rate threshold is based at least partially on the number of occupants aircraft <NUM> is designed to transport. Accordingly, in one example, air distribution systems <NUM> and <NUM> are operable to discharge conditioned air from nozzles <NUM> and <NUM> at a flow rate greater than about <NUM> pounds per minute per occupant (lbs/min/occupant) i.e. <NUM>/min/occupant, greater than about <NUM> lbs/min/occupant (<NUM>/min/occupant), greater than about <NUM> lbs/min/occupant (<NUM>/min/occupant), or greater than about <NUM> lbs/min/occupant (<NUM>/min/occupant). The velocity threshold is based at least partially on a perceived comfort level of occupants of passenger cabin <NUM>. Accordingly, in operation, air distribution systems <NUM> and <NUM> are operable to discharge conditioned air <NUM> from nozzles <NUM> and <NUM> into passenger cabin <NUM> at a velocity that is less than a threshold in which occupants of passenger cabin <NUM> may perceive an undesirable draft at their seat <NUM>. Accordingly, air distribution systems <NUM> and <NUM> discharge conditioned air <NUM> at a velocity of less than about <NUM> feet per minute (ft/min) (i.e. <NUM>-<NUM>), less than about <NUM> ft/min (i.e. <NUM>-<NUM>), less than about <NUM> ft/min (i.e. <NUM>-<NUM>), or less than about <NUM> ft/min (i.e. <NUM>-<NUM>).

The systems and methods described are not limited to the specific embodiments described herein, but rather, components of the systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein.

Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only.

As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural elements or steps unless such exclusion is explicitly recited. Furthermore, references to "one embodiment" of the present invention or the "example embodiment" are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

Claim 1:
An aircraft (<NUM>) comprising:
a fuselage (<NUM>) comprising a side wall (<NUM>) at least partially defining a passenger cabin (<NUM>) and a crown section (<NUM>) of the aircraft, wherein the passenger cabin includes an overhead zone (<NUM>), a passenger zone (<NUM>), and a floor zone (<NUM>);
an air supply duct (<NUM>) positioned within the crown section (<NUM>), wherein the air supply duct (<NUM>) is configured to pressurize the crown section (<NUM>) with air;
at least one return air outlet (<NUM>) defined in the floor zone (<NUM>); and
an interior structure (<NUM>) coupled to the side wall (<NUM>) and extending between the passenger cabin (<NUM>) and the crown section (<NUM>), the interior structure (<NUM>) comprising a plurality of nozzles (<NUM>) oriented to discharge the air from the pressurized crown section (<NUM>) along an airflow path (<NUM>) that extends downward through the overhead zone, downward through the passenger zone (<NUM>), and then towards the at least one return air outlet (<NUM>).