Forward Tilted Turbine Nozzle Aerodynamic Efficiency
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Solution Overview
Problem
Modern turbofan engines face challenges in maximizing efficiency and reducing fuel consumption due to the increasing cost of jet fuel, necessitating further improvements in turbine stage design.
Innovation Solution
The design incorporates a turbine nozzle with radially outwardly inclined outer and inner bands, each vane having camber and an acute twist angle to import swirl in combustion gases, along with counterrotation of the HPT and LPT rotors, and a forward-tilted trailing edge configuration in the first stage LP nozzle to enhance aerodynamic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional turbine nozzle design is used, then structural simplicity is maintained, but aerodynamic efficiency is insufficient
Solution Approach 1:
The patent applies local quality by tilting only the trailing edge portion of the nozzle vanes forward while keeping the leading edge and root portion in conventional positions. This localized modification optimizes the aerodynamic flow path at the critical trailing edge region where gas expansion occurs, improving aerodynamic efficiency without requiring complete redesign of the entire nozzle structure.
Solution Approach 2:
The invention introduces a new dimensional parameter - the forward tilt angle of the trailing edge - to the conventional vane geometry. By adding this angular dimension to the trailing edge configuration, the patent creates a three-dimensional vane shape that better matches the flow dynamics of expanding combustion gases, thereby enhancing aerodynamic performance.
2Loss of energy
If turbine stage design is optimized for maximum efficiency, then fuel consumption increases
Solution Approach 1:
The patent changes the geometric parameters of the turbine nozzle by implementing a forward tilt of the trailing edge at specific angles. This parameter modification optimizes the expansion path of combustion gases, improving energy extraction efficiency from the turbine stages and thereby reducing fuel consumption for the same power output.
3Use of energy by moving object
If vane trailing edges are tilted forward, then aerodynamic efficiency increases, but manufacturing complexity increases
Solution Approach 1:
The vane structure is segmented into distinct zones: the leading edge portion maintains conventional geometry for easy manufacturing, while only the trailing edge portion is tilted forward. This segmentation allows standard manufacturing processes to be used for the majority of the vane, while the tilted trailing edge can be added through specialized but localized processes, balancing manufacturability with aerodynamic 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
This configuration significantly increases the aerodynamic efficiency of the turbine stages, reduces the complexity and weight of the engine, and decreases fuel consumption, while maintaining or increasing swirl, thereby enhancing overall engine performance.
Implementation Method 1
Each vane has camber and an acute twist angle for importing swirl in combustion gases discharged at trailing edges thereof
Implementation Method 2
The trailing edges are tilted forwardly from the inner band to the outer band for increasing aerodynamic efficiency
Data Source
AI summary
A turbine nozzle includes a row of vanes joined to radially outwardly inclined outer and inner bands. Each vane has camber and an acute twist angle for importing swirl in combustion gases discharged at trailing edges thereof. The trailing edges are tilted forwardly from the inner band to the outer band for increasing aerodynamic efficiency.