Annular Diffuser Partitioning for Gas Turbine Friction Loss
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Solution Overview
Problem
Gas turbine engines experience significant friction loss due to the large wetted-perimeter length of the diffuser flow path, leading to increased pressure loss, which is not effectively addressed by existing designs.
Innovation Solution
The implementation of an annular diffuser with concentric tubular members and partition members that divide the flow path in the circumferential direction, reducing the wetted-perimeter length and minimizing friction loss without substantial dimension changes, while maintaining necessary flow-path area and static pressure recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the flow-path height in the diffuser is reduced to match the compressor outlet, then the diffuser can be connected directly to the compressor, but the wetted-perimeter length increases relative to the cross-sectional area, causing increased friction loss
Solution Approach 1:
The diffuser flow path is segmented into multiple separate flow paths by introducing partition members that extend from the inner peripheral surface to the outer peripheral surface. This segmentation reduces the wetted-perimeter length of each individual flow path while maintaining the total flow capacity, thereby reducing friction loss without compromising the diffuser's connection to the compressor.
2Loss of energy
If partition members are added to divide the diffuser flow path, then the wetted-perimeter length is reduced and friction loss is minimized, but the device complexity increases
Solution Approach 1:
The partition members serve multiple functions simultaneously: they divide the flow path to reduce wetted-perimeter length, provide structural support for the diffuser walls, and act as flow guides. This multi-functionality reduces the need for additional components, thereby minimizing the increase in device complexity while achieving friction loss reduction.
3Loss of energy
If the aspect ratio of the flow-path cross section is increased to reduce wetted-perimeter length, then friction loss is reduced, but the dimension of the diffuser must be increased, which conflicts with maintaining existing engine dimensions
Solution Approach 1:
Instead of increasing the diffuser dimension in the radial direction to improve aspect ratio, the invention introduces a new dimensional approach by segmenting the flow path circumferentially. This creates multiple narrower flow paths with higher aspect ratios without increasing the overall diffuser diameter, thus reducing friction loss while maintaining existing engine dimensions.
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 effectively reduces friction loss and pressure loss in the diffuser, ensuring efficient gas flow to the combustor while maintaining the existing dimensions of the gas turbine engine.
Implementation Method 1
the larger the wetted-perimeter of the flow path is, the greater the friction loss due to the wall surface of the flow path is
Implementation Method 2
a diffuser is provided at an outlet of an axial-flow compressor, whereby static pressure of compressed air is recovered, and pressure loss (mainly, dynamic pressure loss) until the compressed air flows into a combustor is reduced
Data Source
AI summary
A gas turbine engine, in which a compressed gas from a compressor of an axial-flow type is burned in a combustor and an obtained combustion gas drives a turbine, includes: a diffuser of an annular shape connected to an outlet of the compressor, the diffuser including a diffuser inner tube and a diffuser outer tube that are tubular members disposed concentrically with each other; and a plurality of partition members that are disposed in a diffuser flow path, which is an annular space formed between the diffuser inner tube and the diffuser outer tube, and divide the diffuser flow path in a circumferential direction.