Counter-Rotating Turbine Rotor Cooling Flow Redirection

Solution Overview

Problem

Conventional counter-rotating turbine engines experience windage losses due to cooling fluid flow opposing the rotational direction of the inner rotor, leading to decreased power and efficiency.

Innovation Solution

The design includes fluid passages in the outer rotor with an outlet passage centerline oriented to redirect cooling air flow in the direction of the inner rotor's rotation, minimizing windage resistance and aligning fluid flow with the rotational velocity of the downstream blades.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling fluid flow is used to cool the inner rotor, then the inner rotor is effectively cooled, but windage losses increase due to fluid flow opposing the rotational direction

Engineering Contradiction:

Improveinner rotor temperatureVSAvoidwindage losses

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The patent inverts the conventional approach by redirecting the cooling fluid flow to rotate in the same direction as the inner rotor rather than opposing it. The fluid passage is configured with a specific orientation that causes the cooling air to move co-rotating with the inner rotor, transforming the harmful opposing flow into a beneficial co-rotating flow that reduces windage losses while maintaining cooling effectiveness

Inventive Principle:

Principle #13The other way round (Inversion)

2Temperature

If cooling fluid flow is used to cool the inner rotor, then the inner rotor is effectively cooled, but power output decreases due to increased resistance

Engineering Contradiction:

Improveinner rotor temperatureVSAvoidpower output

Core Design Contradiction:

TemperatureVSPower

Solution Approach 1:

The patent inverts the conventional approach by redirecting the cooling fluid flow to rotate in the same direction as the inner rotor rather than opposing it. The fluid passage is configured with a specific orientation that causes the cooling air to move co-rotating with the inner rotor, transforming the harmful opposing flow into a beneficial co-rotating flow that reduces windage losses while maintaining cooling effectiveness

Inventive Principle:

Principle #13The other way round (Inversion)

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 redirection of fluid flow reduces windage losses and increases the overall power output of the turbine engine without altering other engine performance parameters, enhancing efficiency and power without the need for additional components or material changes.

Implementation Method 1

the fluid passages have a passage centerline oriented to redirect a fluid flow within the fluid passages from the first rotational direction to the second rotational direction

Methodology Applied

Scientific EffectFluid flow redirection:

Implementation Method 2

a fluid passage from one rotor cooling the other rotor

Methodology Applied

Scientific EffectHeat transfer:

Data Source

PatentUS11739643B2Method and apparatus for cooling a portion of a counter-rotating turbine engine

Publication Date: 2023.08.29 GE AVIO SRL

AI summary

A turbine engine having counter-rotating rotors comprising a first rotor, rotating in a first rotational direction, defining a first rotor set of blades axially spaced to define a gap, and a second rotor, rotating in a second rotational direction counter the first rotational direction. The second rotor further including a second set of blades received within the gap of the first rotor. A plurality of fluid passages is formed in the first rotor with an outlet facing the gap.