Variable-Area Turbine Nozzle Assembly Using Differential Thermal Expansion
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Solution Overview
Problem
Static nozzle segments in gas turbine engines do not provide efficient fluid 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, controlled by linkages, to adjust the turning angle of the trailing edge of the vanes in response to temperature changes, thereby optimizing fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If static nozzle segments are used, then the structure is simple and reliable, but fluid flow direction and pressure control efficiency decreases across varying operating conditions
Solution Approach 1:
The patent transforms the static nozzle structure into a dynamic one by enabling the nozzle segments to rotate about their longitudinal axes. This rotation is controlled by actuators that adjust the nozzle angle based on operating conditions, allowing the system to adapt fluid flow direction and pressure dynamically while maintaining structural reliability through controlled movement mechanisms
2Productivity
If variable vanes are implemented to enhance flow direction and pressure, then fluid flow efficiency improves, but device complexity increases
Solution Approach 1:
The nozzle is divided into multiple independent segments that can rotate individually or in coordinated groups. Each segment is equipped with its own actuator, allowing localized adjustment of flow direction. This segmentation enables efficient fluid flow control while distributing the complexity across modular components rather than requiring a completely redesigned complex system
Solution Approach 2:
The variable nozzle segments serve multiple functions: they control fluid flow direction, regulate pressure, and can adapt to different operating conditions (idle, partial load, full load). This multi-functionality reduces the need for separate systems for each function, thereby improving fluid flow efficiency without proportionally increasing overall device complexity
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 fluid flow direction and pressure control across varying operating conditions, improving the efficiency of the gas turbine engine.
Implementation Method 1
An inner support ring is spaced radially outward from the guide vane, the inner support ring defines an opening... An outer support ring extends circumferentially around the inner support ring... wherein the at least one linkage is configured to rotate the guide vane about a centerline of the outer centering pin in response to a change in operational temperature of a combustion gas
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.