Gas Turbine Strut Strip Vortex Flow Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing strut structures in exhaust diffusers of gas turbines suffer from a separated flow phenomenon, leading to pressure loss due to the formation of vortices when exhaust gas passes through the struts, which reduces efficiency.

Innovation Solution

The proposed solution involves a strut structure with strips disposed in columns along the outer circumference of the diffuser body, where the strips are designed to form corner and streamwise vortices by adjusting their height, width, and spacing to alleviate the separated flow issue, thereby reducing pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional strut structures are used in exhaust diffusers, then the structure is simple, but separated flow phenomenon occurs leading to pressure loss

Engineering Contradiction:
Improvepressure lossVSAvoidstrut structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The strut surface is segmented by adding multiple strips (first strips and second strips) at different positions and orientations. These strips divide the continuous strut surface into distinct zones that independently control flow behavior, preventing large-scale separated flow while maintaining overall structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Strips are added in the spanwise direction (perpendicular to the main flow direction) to create a three-dimensional flow control structure. This dimensional addition transforms the two-dimensional strut surface into a multi-zone flow management system that generates beneficial vortices and delays flow separation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If strips are added to the strut to form vortices and reduce separated flow, then pressure loss is reduced, but the strut structure becomes more complex

Engineering Contradiction:
Improveexhaust gas flow efficiencyVSAvoidstrut structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Different strips are positioned at specific locations (leading edge, mid-section, trailing edge) with varying orientations and dimensions tailored to local flow conditions. Each strip zone addresses specific flow separation tendencies in its region, optimizing overall exhaust gas flow efficiency through localized flow control.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The strips have specific dimensional parameters (width, height, spacing) and orientation angles that are optimized to generate appropriate vortex strength and flow attachment. By carefully controlling these geometric parameters, the structure achieves flow control functionality while limiting complexity through standardized design rules.

Inventive Principle:
Principle #35Parameter changes

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

The design effectively suppresses the separated flow phenomenon, forming corner and streamwise vortices that improve the lift coefficient and reduce drag, ultimately enhancing the efficiency of the gas turbine by minimizing pressure loss.

Implementation Method 1

corner vortices are formed on the leading edge of the strut, and if the exhaust gas flows along the strip, streamwise vortices may be formed to alleviate a pressure loss

Methodology Applied
Scientific EffectVortex formation: Vortex Generator

Implementation Method 2

alleviating a separated flow phenomenon of the exhaust gas passing through the strut

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Data Source

PatentEP3835546B1Strut structure with strip for exhaust diffuser and gas turbine having the same
Publication Date: 2023.05.31 DOOSAN ENERBILITY CO LTD
  • EP3835546B1 patent drawingFigure 1
  • EP3835546B1 patent drawingFigure 2
  • EP3835546B1 patent drawingFigure 3

AI summary

A strut structure with a strip for an exhaust diffuser of a gas turbine and a gas turbine having the same are provided. The strut structure with a strip for an exhaust diffuser of a gas turbine is configured to include a plurality of struts disposed along an outer circumference of a diffuser body disposed on a central side of the exhaust diffuser, and one or more strips formed on the strut, wherein an exhaust gas passing through the strut flows along the strip from a leading edge of the strut to alleviate a separated flow phenomenon, and wherein if the exhaust gas enters the strip, corner vortices are formed on the leading edge of the strut, and if the exhaust gas flows along the strip, streamwise vortices are formed to alleviate a pressure loss of the exhaust gas.