Safran has been granted a patent for a confluence structure in an aircraft bypass turbine engine. The structure includes a confluence plate with a movable downstream end, allowing for adjustments in flight. The secondary stream is delimited by a movable sleeve and an inner projection of the outer casing can also slide axially. This design provides flexibility in modifying gas dilution and engine operating conditions. GlobalData’s report on Safran gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Safran, photovoltaic drones was a key innovation area identified from patents. Safran's grant share as of June 2023 was 1%. Grant share is based on the ratio of number of grants to total number of patents.
Confluence structure for modifying gas dilution in aircraft engine
A recently granted patent (Publication Number: US11686274B2) describes a confluence structure for an aircraft engine that combines a primary stream and a secondary stream. The confluence structure includes a confluence plate that separates the primary and secondary streams downstream of a low-pressure turbine. The confluence plate has a revolution shape and a moving part that can slide adjustably in the axial direction with respect to a fixed complementary part. The primary and secondary streams only join together downstream of the confluence plate's downstream end.
The confluence structure also includes a shell mounted in the outer casing, forming an annular outer channel. The shell extends downstream of the confluence plate's downstream end and has a moving part that can slide adjustably in the axial direction with respect to a fixed complementary part. The outer casing comprises a projection that projects radially inwards into the secondary stream, and the moving part of the shell can be positioned upstream or downstream of the projection.
The patent also describes various features of the confluence structure, including a curved portion that belongs to the shell and surrounds the downstream end, and a curved portion that connects the complementary part to the moving part of the confluence plate. These curved portions have a variation in radius without sudden slope variation. The confluence structure also includes radial extension elements, such as afterburn fuel injector pencils or flame holder arms, which can traverse the moving parts of the confluence plate and the shell through oblong piercings covered with airtight seals.
Adjustment devices, such as pivoting pins with cams, are used to displace the moving parts of the confluence plate and the shell. These adjustment devices extend outside of the outer casing and can be centered on liners using ball joints. The moving parts of the confluence plate and the shell are connected to the complementary parts by compressed springs in the radial direction.
The patent also mentions that the confluence structure can be used in a bypass turbine engine. Overall, this granted patent describes a confluence structure for an aircraft engine that allows for adjustable positioning of the primary and secondary streams, providing potential benefits in terms of engine performance and efficiency.