Turbomachine Blade Platform Asymmetry for Secondary Flow Reduction

Solution Overview

Problem

Current turbomachines experience significant secondary flows and pressure losses due to the interaction of fluid flows with the side walls, which are not adequately addressed by existing contouring methods.

Innovation Solution

A blade grid segment with an axis-asymmetric platform surface featuring an elevation that extends from the pressure side of one airfoil to the suction side of another, where the highest point of the elevation is closer to the suction side, reducing secondary flows by influencing the static pressure field and vortex formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional axisymmetric platform surfaces are used, then manufacturing is simple, but secondary flows and pressure losses are significant

Engineering Contradiction:

Improvepressure lossesVSAvoidplatform surface geometry

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by designing a non-axisymmetric platform surface with an elevation that has a specific asymmetric configuration. The elevation extends from the pressure side to the suction side with its highest point positioned closer to the suction side, creating an asymmetric geometry that actively influences the fluid flow to reduce secondary flows and pressure losses.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by introducing an elevation at a specific location on the platform surface rather than modifying the entire surface uniformly. The elevation is positioned in the blade interstrip region with its highest point at a specific location, creating a localized modification that targets the reduction of secondary flows in critical areas while maintaining simplicity elsewhere.

Inventive Principle:

Principle #3Local quality

2Loss of energy

If non-axisymmetric platform surfaces are used, then secondary flows are reduced, but manufacturing complexity increases

Engineering Contradiction:

Improvesecondary flowsVSAvoidplatform surface geometry

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by designing a non-axisymmetric platform surface with an elevation that has a specific asymmetric configuration. The elevation extends from the pressure side to the suction side with its highest point positioned closer to the suction side, creating an asymmetric geometry that actively influences the fluid flow to reduce secondary flows and pressure losses.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by introducing an elevation at a specific location on the platform surface rather than modifying the entire surface uniformly. The elevation is positioned in the blade interstrip region with its highest point at a specific location, creating a localized modification that targets the reduction of secondary flows in critical areas while maintaining simplicity elsewhere.

Inventive Principle:

Principle #3Local quality

3Loss of energy

If the highest point of the elevation is centered, then symmetry is maintained, but secondary flow reduction is less effective

Engineering Contradiction:

Improvesecondary flow reductionVSAvoidelevation symmetry

Core Design Contradiction:

Loss of energyVSShape

Solution Approach 1:

The patent applies asymmetry by positioning the highest point of the elevation closer to the suction side rather than at the center. This asymmetric positioning is crucial for effectively reducing secondary flows, as it creates a specific pressure field distribution that counteracts the secondary flow generation mechanisms in the blade channel.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by introducing an elevation at a specific location on the platform surface rather than modifying the entire surface uniformly. The elevation is positioned in the blade interstrip region with its highest point at a specific location, creating a localized modification that targets the reduction of secondary flows in critical areas while maintaining simplicity elsewhere.

Inventive Principle:

Principle #3Local quality

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 effectively reduces secondary flows and pressure losses, improving the inflow into subsequent blade grids and enhancing the overall efficiency of the turbomachine by optimizing the geometry of the platform surface.

Implementation Method 1

reducing secondary flows by influencing the static pressure field and vortex formation

Methodology Applied

Scientific EffectStatic pressure field influence: Pressure Gradient

Data Source

PatentEP3404210B1Blade cascade segment for a turbomachine with non-axisymmetric platform surface, corresponding blade cascade, blade channel, platform, and turbomachine

Publication Date: 2024.07.31 MTU AERO ENGINES GMBH

Figure 1~2
Figure 3

AI summary

A blade grid segment (100, 200, 300) with at least two blades (20, 30) and a platform (10) having an axially asymmetric platform surface (12) is disclosed. This platform surface has a protrusion (110, 210, 310) extending from the pressure side (21) of the first blade to the suction side (32) of the second blade (30). A highest point (111, 211, 311) of the protrusion is located closer to the suction side (32) of the second blade (30) than to the pressure side (21) of the first blade (20). Also disclosed are a blade grid, a platform, a blade channel, and a turbomachine.