Hollow Turbine Rotor Air Routing for Balance Piston Thrust Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas turbine engines face challenges in balancing fuel efficiency, operational efficiency, and power output while managing weight, part count, and packaging dimensions, particularly due to the need for significant cooling air to mitigate hot combustion gases and the inefficiencies in accelerating combustion gases to match high-pressure turbine rotor speeds.
Innovation Solution
The design incorporates a turbine section with a stationary outer portion and interdigitated rotating components, featuring a hollow passageway in the aft airfoil that is in fluid communication with the stationary outer portion and a balance piston cavity, allowing air flow to counteract thrust loads and provide integrated cooling, thereby optimizing axial thrust and reducing bearing loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If nozzle guide vanes are used to accelerate combustion gases to match high pressure turbine rotor speed, then engine operability and performance are improved, but device complexity and cooling air requirements increase
Solution Approach 1:
The patent combines the functions of the nozzle guide vane and the balance piston into a single integrated component. The nozzle guide vane is configured with a balance piston cavity that receives combustion gases, allowing the same structure to both accelerate gases and generate axial thrust to counteract rotor thrust loads, thereby reducing the need for separate cooling air systems and reducing overall device complexity
Solution Approach 2:
The nozzle guide vane is designed to perform multiple functions simultaneously: accelerating combustion gases tangentially to match rotor speed, generating axial thrust through the balance piston cavity to counteract rotor thrust loads, and providing cooling air passage. This multi-functionality reduces the number of separate components needed and optimizes engine performance
2Reliability
If nozzle guide vanes are designed to withstand maximum combustion gas temperature, then reliability is improved, but considerable quantities of cooling air are required
Solution Approach 1:
The patent utilizes the pressure and flow characteristics of combustion gases themselves to provide cooling and thrust generation. The balance piston cavity captures combustion gases and converts their thermal and pressure energy into axial thrust, while also using the gas flow for cooling the nozzle guide vane, thereby reducing the need for additional cooling air from the compressor
Solution Approach 2:
The nozzle guide vane system uses its own operating environment (combustion gases) to provide its own cooling and thrust balance. The combustion gases passing through the balance piston cavity directly cool the nozzle guide vane and generate the necessary axial thrust, making the system self-sufficient and reducing external cooling air requirements
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 enhances fuel efficiency, operational efficiency, and power output while reducing weight and packaging, enabling increased bypass ratios and overall pressure ratios, and reduces the product of axial flow area and rotational speed, thus improving engine performance and efficiency.
Implementation Method 1
a pressure of the flow of air within the balance piston cavity is controlled to provide an axial thrust that counteracts a thrust load on the second rotor portion
Implementation Method 2
a flow of air is routed through the stationary outer portion and the hollow passageway to the balance piston cavity
Data Source
AI summary
A gas turbine engine defining a longitudinal direction and a radial direction is provided. The gas turbine engine includes a turbine section comprising a stationary outer portion, a first rotating component, and a second rotating component, wherein the first rotating component includes an aft airfoil defining a hollow passageway and coupled to a radially extended first rotor portion, wherein the hollow passageway is in fluid communication with the stationary outer portion, wherein the second rotating component is coupled to a radially extended second rotor portion; and a seal assembly between a portion of the first rotating component and the second rotating component, the seal assembly defining a balance piston cavity therebetween, wherein the balance piston cavity is in fluid communication with the hollow passageway, wherein a flow of air is routed through the stationary outer portion and the hollow passageway to the balance piston cavity, and wherein a pressure of the flow of air within the balance piston cavity is controlled to provide an axial thrust that counteracts a thrust load on the second rotor portion.