Pre-swirl Nozzle with Expanding Diffuser for Cooling Air Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pre-swirl nozzle systems in gas turbines, particularly in aircraft engines, face challenges in efficiently managing the transition of cooling air from stationary to rotating components, leading to energy loss and inefficient cooling due to constant cross-section designs that restrict independent control over mass flow and exit velocity.
Innovation Solution
The introduction of a pre-swirl nozzle system with a region of constant cross section followed by a downstream expanding diffuser region, allowing for independent setting of mass flow and exit velocity through varying cross-sectional shapes and expansion methods, such as linear or non-linear, to optimize cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a pre-swirl nozzle has a constant cross section throughout, then the structure is simple, but the mass flow and exit velocity cannot be set independently
Solution Approach 1:
The pre-swirl nozzle is divided into multiple sections along the flow direction: a first section with a first cross-sectional area, a second section with a second cross-sectional area, and a third section with a third cross-sectional area. This segmentation allows independent control of mass flow and exit velocity by adjusting the area ratios between sections, resolving the contradiction between structural simplicity and control versatility.
Solution Approach 2:
The patent changes the cross-sectional area parameter along the flow direction by introducing intermediate sections with different areas. Specifically, the first cross-sectional area is larger than the second, which is larger than the third, creating a stepped area reduction that enables independent setting of mass flow and exit velocity while maintaining reasonable structural complexity.
2Speed
If the cross-sectional area is reduced abruptly, then the exit velocity increases, but pressure loss increases
Solution Approach 1:
Instead of a single abrupt area reduction, the patent implements a dynamic, multi-stage area reduction through intermediate sections. The stepped configuration with progressively smaller areas (first > second > third) allows the flow to adapt gradually, reducing pressure loss while achieving the desired exit velocity through cumulative area reduction.
Solution Approach 2:
The second section with the intermediate cross-sectional area acts as an intermediary between the first and third sections. This intermediate section mediates the transition from larger to smaller area, allowing the flow to adjust progressively and reducing the harmful pressure losses associated with abrupt area changes while still achieving high exit velocity.
3Loss of energy
If the pre-swirl nozzle aligns cooling air at an angle to the turbine inlet stage, then pressure loss is minimized, but the nozzle structure becomes more complex
Solution Approach 1:
The nozzle is segmented into multiple sections, each potentially with different angular orientations. This segmentation allows the cooling air to be aligned at optimal angles relative to the turbine inlet stage while maintaining manageable geometric complexity through modular section design rather than a single complex angled structure.
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 design enhances cooling efficiency by minimizing pressure loss and allowing for independent control of mass flow and exit velocity, effectively reducing energy loss and improving turbine component cooling, particularly in high-temperature applications.
Implementation Method 1
a downstream region with a second cross section, which expands in the flow direction... a region with a constant cross section is followed by a diffuser region, resulting in regions of different velocity within the pre-swirl nozzle
Data Source
AI summary
The invention relates to a pre-swirl nozzle system in a gas turbine, in particular in an aircraft engine, having at least one pre-swirl nozzle, through which cooling air can flow, characterized in that the at least one pre-swirl nozzle has a region with a constant first cross section and a downstream region with a second cross section, which expands in the flow direction, in particular expands in a strictly monotonic manner.