A shield assembly that may be disposed within an engine compartment of an agricultural vehicle, the shield assembly includes a plurality of shields that may block buildup of debris within the engine compartment. At least one shield of the plurality of shields includes a sloped surface that may direct debris away from the engine compartment. The shield assembly also includes a plurality of ducts formed between the plurality of shields. The plurality of ducts may redirect cooling fluid from a cooling fan package to the engine compartment to remove debris from within the engine compartment.

A method for supplying air to an engine of an aircraft via an air supply system of the aircraft. A dynamic air intake vent of the system can be closed by a closure member that is movable between a closed position and an open position. A static air intake vent is equipped with a filter medium. During flight, the method comprises an unfiltered operating mode that comprises the following steps: positioning of the closure member in the open position, and, during a phase of forward travel of the aircraft, dynamic intake of a flow of air, then transfer of a first portion of the flow of air to the engine and a second portion of the flow of air to the filter medium in order to clean the filter medium.

Systems and methods to increase intake air flow to a gas turbine engine of a hydraulic fracturing unit when positioned in an enclosure may include providing an intake expansion assembly to enhance intake air flow to the gas turbine engine. The intake expansion assembly may include an intake expansion wall defining a plurality of intake ports positioned to supply intake air to the gas turbine engine. The intake expansion assembly also may include one or more actuators connected to a main housing of the enclosure and the intake expansion assembly. The one or more actuators may be positioned to cause the intake expansion wall to move relative to the main housing between a first position preventing air flow through the plurality of intake ports and a second position providing air flow through the plurality of intake ports to an interior of the enclosure.

Systems and methods to increase intake air flow to a gas turbine engine of a hydraulic fracturing unit when positioned in an enclosure may include providing an intake expansion assembly to enhance intake air flow to the gas turbine engine. The intake expansion assembly may include an intake expansion wall defining a plurality of intake ports positioned to supply intake air to the gas turbine engine. The intake expansion assembly also may include one or more actuators connected to a main housing of the enclosure and the intake expansion assembly. The one or more actuators may be positioned to cause the intake expansion wall to move relative to the main housing between a first position preventing air flow through the plurality of intake ports and a second position providing air flow through the plurality of intake ports to an interior of the enclosure.

A shroud having an annular member extending along an axis from a first end to a second end. The annular member has an inside surface radially inward from an outside surface that diverges from the first end towards the second end relative to the axis. The shroud further includes a flange that extends radially outward from the outside surface and a recess, each located at the second end. The recess extends radially outward from the inside surface and circumferentially about the axis. An axial extent of the recess at least partially coincides with an axial extent of the flange.

A shroud having an annular member extending along an axis from a first end to a second end. The annular member has an inside surface radially inward from an outside surface that diverges from the first end towards the second end relative to the axis. The shroud further includes a flange that extends radially outward from the outside surface and a recess, each located at the second end. The recess extends radially outward from the inside surface and circumferentially about the axis. An axial extent of the recess at least partially coincides with an axial extent of the flange.

A plenum duct for an auxiliary power unit includes a main body having an inlet aperture and a flow cavity. A pair of screen supports are coupled to the main body proximate a periphery of the inlet aperture, said screen supports extending into the flow cavity. A pleated screen is disposed on the pair of screen supports.

A plenum duct for an auxiliary power unit includes a main body having an inlet aperture and a flow cavity. A pair of screen supports are coupled to the main body proximate a periphery of the inlet aperture, said screen supports extending into the flow cavity. A pleated screen is disposed on the pair of screen supports.

A screen for an air intake portion of a machine is provided. The screen includes an assembly of screen members that form a plurality of screen cells, wherein at least a portion of the screen cells define an irregular configuration.

A screen for an air intake portion of a machine is provided. The screen includes an assembly of screen members that form a plurality of screen cells, wherein at least a portion of the screen cells define an irregular configuration.