Abstract: There is provided a vehicle configuration to reduce drag in a fluid stream. The vehicle configuration has a vehicle body. The vehicle configuration further has at least one auxiliary body coupled to, and positioned a distance from, the vehicle body, to form a channel between the at least one auxiliary body and the vehicle body. The vehicle configuration further has one or more exterior profiles of one or more of, the vehicle body and the at least one auxiliary body. The one or more exterior profiles are positioned in proximity to the channel, and are shaped with an aerodynamic shaping, so that the one or more exterior profiles each comprises one or more concave shape portions. When a fluid flow from the fluid stream flows through the channel, the drag resulting from fluid flow interactions between the vehicle body and the at least one auxiliary body is reduced.

Abstract: There is provided a vehicle configuration to reduce drag in a fluid stream. The vehicle configuration has a vehicle body. The vehicle configuration further has at least one auxiliary body coupled to, and positioned a distance from, the vehicle body, to form a channel between the at least one auxiliary body and the vehicle body. The vehicle configuration further has one or more exterior profiles of one or more of, the vehicle body and the at least one auxiliary body. The one or more exterior profiles are positioned in proximity to the channel, and are shaped with an aerodynamic shaping, so that the one or more exterior profiles each comprises one or more concave shape portions. When a fluid flow from the fluid stream flows through the channel, the drag resulting from fluid flow interactions between the vehicle body and the at least one auxiliary body is reduced.

Abstract: There is provided a turbofan engine for an aircraft. The turbofan engine has a core with a fan cowl and a variable pitch fan (VPF) configured to only rotate in a first rotation direction. The VPF has a plurality of fan blades each configured to over-pitch to an over-pitch position relative to a feathered position. The turbofan engine has outer guide vanes (OGVs) axially disposed downstream of the VPF, and has a rotation control device to prevent the VPF from rotating in a second rotation direction opposite the first rotation direction, during an engine out (EO) condition of the turbofan engine. When the VPF is prevented from rotating during the EO condition, the fan blades are over-pitched to the over-pitch position relative to the feathered position, to achieve no or minimal air flow separation about the OGVs, and to reduce drag of the turbofan engine during the EO condition.

Abstract: There is provided a turbofan engine for an aircraft. The turbofan engine has a core with a fan cowl and a variable pitch fan (VPF) configured to only rotate in a first rotation direction. The VPF has a plurality of fan blades each configured to over-pitch to an over-pitch position relative to a feathered position. The turbofan engine has outer guide vanes (OGVs) axially disposed downstream of the VPF, and has a rotation control device to prevent the VPF from rotating in a second rotation direction opposite the first rotation direction, during an engine out (EO) condition of the turbofan engine. When the VPF is prevented from rotating during the EO condition, the fan blades are over-pitched to the over-pitch position relative to the feathered position, to achieve no or minimal air flow separation about the OGVs, and to reduce drag of the turbofan engine during the EO condition.

Abstract: A winglet system for an aircraft wing includes an upper winglet and a lower winglet mounted to a wing. The lower winglet has a static position when the wing is subject to an on-ground static loading. The lower winglet is configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading. The lower winglet is configured to aeroelastically deflect upwardly under the approximate 1-g flight loading and further increase the effective span of the wing beyond the effective span increase that is caused by the upward deflection of the wing.

Abstract: A winglet system for an aircraft wing includes an upper winglet and a lower winglet mounted to a wing. The lower winglet has a static position when the wing is subject to an on-ground static loading. The lower winglet is configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading. The lower winglet is configured to aeroelastically deflect upwardly under the approximate 1-g flight loading and further increase the effective span of the wing beyond the effective span increase that is caused by the upward deflection of the wing.

Abstract: A winglet system for an aircraft wing includes an upper winglet and a lower winglet mounted to a wing. The lower winglet has a static position when the wing is subject to an on-ground static loading. The lower winglet is configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading. The lower winglet is configured to aeroelastically deflect upwardly under the approximate 1-g flight loading and further increase the effective span of the wing beyond the effective span increase that is caused by the upward deflection of the wing.

Abstract: A winglet system for an aircraft wing includes an upper winglet and a lower winglet mounted to a wing. The lower winglet has a static position when the wing is subject to an on-ground static loading. The lower winglet may be substantially straight in the static position. The lower winglet is configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading.

Abstract: A winglet system for an aircraft wing includes an upper winglet and a lower winglet mounted to a wing. The lower winglet has a static position when the wing is subject to an on-ground static loading. The lower winglet may be substantially straight in the static position. The lower winglet is configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading.

Abstract: A winglet system for an aircraft wing may include an upper winglet and a lower winglet mounted to a wing tip. The upper winglet root chord and the lower winglet root chord may each have a length of no greater than 100 percent of the wing tip chord. The lower winglet may have a static position when the wing is subject to an on-ground static loading. The lower winglet may be configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading.

Abstract: A winglet system for an aircraft wing may include an upper winglet and a lower winglet mounted to a wing tip. The upper winglet root chord and the lower winglet root chord may each have a length of no greater than 100 percent of the wing tip chord. The lower winglet may have a static position when the wing is subject to an on-ground static loading. The lower winglet may be configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading.

Abstract: A winglet system for an aircraft wing may include an upper winglet and a lower winglet mounted to a wing tip. The lower winglet may have a static position when the wing is subject to an on-ground static loading. The lower winglet may be configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading. The lower winglet may have a length of approximately 50-80 percent of a length of the upper winglet.

Abstract: A winglet system for an aircraft wing may include an upper winglet and a lower winglet mounted to a wing tip. The lower winglet may have a static position when the wing is subject to an on-ground static loading. The lower winglet may be configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading. The lower winglet may have a length of approximately 50-80 percent of a length of the upper winglet.

Abstract: A winglet system for an aircraft wing may include an upper winglet and a lower winglet mounted to a wing tip. The lower winglet may have a static position when the wing is subject to a ground static loading. The lower winglet may be configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move from the static position to an in-flight position and resulting in a relative span increase of the wing.

Abstract: A winglet system for an aircraft wing may include an upper winglet and a lower winglet mounted to a wing tip. The lower winglet may have a static position when the wing is subject to a ground static loading. The lower winglet may be configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move from the static position to an in-flight position and resulting in a relative span increase of the wing.