Variable-Area Turbine Nozzle Assembly with Thermal-Expansion Vane Control
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Solution Overview
Problem
Static vanes in gas turbine engines do not provide efficient gas flow direction and pressure over a wide range of operating conditions, leading to decreased efficiency.
Innovation Solution
A variable area turbine nozzle assembly with guide vanes that utilize differential radial growth of inner and outer support rings with different thermal expansion coefficients, linked by linkages, to control the turning angle of the vanes and adjust the turbine nozzle throat area in response to temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If static nozzle segments are used to direct gas flow, then the structure is simple, but gas flow direction and pressure efficiency decreases over full range of operating conditions
Solution Approach 1:
The patent implements variable area turbine nozzles with movable nozzle segments that can dynamically adjust their position and area in response to changing operating conditions. The nozzle segments are coupled to actuators that receive control signals to modify the nozzle throat area, enabling the system to adapt to varying mass flow rates and maintain optimal gas flow direction and pressure across the full operating range, thereby resolving the contradiction between structural simplicity and flow efficiency.
Solution Approach 2:
The patent changes the geometric parameters of the nozzle by varying the throat area through movable segments. By adjusting the nozzle area parameter in response to operating conditions (such as mass flow rate changes), the system maintains efficient gas flow direction and pressure control, overcoming the limitation of static nozzles that operate efficiently only at design conditions.
2Productivity
If variable vanes are used to enhance flow direction and pressure, then gas flow efficiency improves, but device complexity increases
Solution Approach 1:
The patent divides the nozzle into multiple independent movable segments rather than using a single complex variable geometry mechanism. Each segment can be independently actuated, allowing for simpler individual components that collectively achieve variable area control. This segmentation approach enables efficient flow direction control while keeping individual component complexity manageable.
Solution Approach 2:
The movable nozzle segments serve multiple functions: they control the nozzle throat area, direct gas flow, and accommodate thermal expansion. By integrating these functions into a single mechanism, the patent avoids the need for separate systems for each function, thereby reducing overall device complexity while maintaining gas flow efficiency.
3Productivity
If nozzle area is adjusted for varying operating conditions, then engine efficiency improves, but control system complexity increases
Solution Approach 1:
The patent implements a control system that automatically adjusts the nozzle area in response to sensed operating conditions such as mass flow rate changes. The control system receives inputs from sensors and autonomously actuates the nozzle segments without requiring manual intervention, enabling the system to self-optimize for varying operating conditions and maintain peak efficiency across the operating range.
Solution Approach 2:
The patent incorporates feedback control where sensors monitor operating conditions (such as mass flow rate) and provide signals to the actuator control system. The control system uses this feedback information to adjust the nozzle throat area in real-time, ensuring optimal performance. This closed-loop feedback mechanism enables efficient adaptation to changing conditions while keeping the control logic manageable through established control algorithms.
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
Enhances gas flow direction and pressure control across varying operating conditions, improving engine efficiency by dynamically adjusting the nozzle throat area.
Implementation Method 1
the inner support ring is spaced radially outward from the guide vane, the inner support ring defining an opening and having a first coefficient of thermal expansion
Implementation Method 2
at least one linkage joining the inner support ring to the outer support ring, wherein the at least one linkage is configured to rotate the guide vane
Data Source
AI summary
A variable area turbine nozzle assembly includes a guide vane including an outer centering pin defining a tab. An inner support ring is spaced radially outward from the guide vane and defines an opening and a protrusion. The protrusion is configured to engage with the tab of the outer centering pin. An outer support ring extends circumferentially around the inner support ring and defines an aperture. The outer support ring has a second coefficient of thermal expansion that is greater than or less than the first coefficient of thermal expansion. At least one linkage joins the inner support ring to the outer support ring and is configured to rotate the inner support ring circumferentially about an axial centerline of the variable area turbine nozzle assembly in response to a change in operational temperature of a combustion gas thus causing the guide vane to rotate.