Sinuous Chevron Exhaust Nozzle Reducing Pressure Losses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chevron exhaust nozzles in gas turbine engines provide noise attenuation but introduce additional pressure losses, increasing fuel consumption and reducing engine efficiency.
Innovation Solution
The design incorporates a row of laterally sinuous chevrons with compound arcuate contours and sinuous trailing edges, which enhance mixing performance while minimizing pressure losses and noise attenuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional chevron exhaust nozzles are used, then noise attenuation is achieved, but pressure losses increase and fuel consumption rises
Solution Approach 1:
The patent applies curvature by transitioning from straight triangular chevrons to arcuate chevrons with curved leading edges and sinuous trailing edges. The curved geometry follows the natural flow lines of the exhaust gases, reducing flow separation and turbulence. This curvature modification maintains the noise attenuation function while significantly reducing pressure losses by creating a more aerodynamic flow path that minimizes energy dissipation.
Solution Approach 2:
The sinuous trailing edge design creates a dynamic mixing pattern that adapts to the flow conditions. The undulating trailing edge promotes controlled turbulence and mixing between core and fan streams, which enhances noise attenuation while the optimized curvature maintains better flow attachment compared to straight edges, thereby reducing pressure losses.
2Object-affected harmful factors
If conventional chevron exhaust nozzles are used, then noise attenuation is achieved, but engine efficiency decreases
Solution Approach 1:
The arcuate chevron design with curved leading edges and sinuous trailing edges optimizes the flow path to reduce turbulence and flow separation. This curvature follows the natural expansion patterns of the exhaust gases, maintaining better flow attachment and reducing energy losses. The result is improved engine efficiency while preserving the noise attenuation benefits of chevron geometry.
Solution Approach 2:
The patent modifies the geometric parameters of the chevrons by introducing curvature radii and sinuous patterns instead of straight edges. These parameter changes optimize the balance between noise attenuation and flow efficiency, creating a design that maintains thrust effectiveness while reducing pressure losses and improving overall engine performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sinuous chevron design reduces aerodynamic performance losses while maintaining noise attenuation, resulting in improved fuel efficiency and reduced fuel consumption compared to traditional triangular chevrons.
Implementation Method 1
the chevrons promote mixing of exhaust flow for noise attenuation
Data Source
AI summary
A gas turbine engine exhaust nozzle includes a row of laterally sinuous chevrons extending from an aft end of an exhaust duct. The chevrons have radially outer and inner surfaces bound by a laterally sinuous trailing edge extending between a base of the chevrons adjoining the duct and an axially opposite apex of the chevrons. Each chevron has a compound arcuate contour both axially and laterally, and the sinuous trailing edge of the chevrons further compounds the arcuate configuration of each chevron.