Turbine Cooling Orifice Control for Vane Tip Clearance

Solution Overview

Problem

Existing turbomachine cooling systems reduce the absolute temperature level of turbine discs, leading to increased thermal expansion and radial clearance, which compromises the performance of the turbomachine.

Innovation Solution

A turbine design with an alternating arrangement of annular rows of movable and fixed blades, incorporating a radially inner annular cavity and a supply circuit with controlled orifices that direct cooling air to different zones of the cavity based on operating conditions, using valves to manage airflow rates for optimal thermal protection and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling air is injected into the cavity to cool the turbine discs, then the thermal protection of the discs is improved, but the radial clearance at the vane tip increases and performance deteriorates

Engineering Contradiction:

Improvetemperature of turbine discsVSAvoidperformance of turbomachine

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The patent applies local quality by providing different cooling zones within the cavity: a radially inner zone for direct disc cooling and a radially outer zone for thermal management. By locally directing cooling air to specific areas rather than uniformly cooling the entire disc, the system achieves thermal protection while minimizing excessive radial clearance that would reduce performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements dynamics through flow rate control means that actively regulate the amount of cooling air supplied to the cavity. This dynamic control allows the system to adapt the cooling intensity based on operating conditions, maintaining optimal balance between thermal protection and performance requirements without fixed, excessive cooling that would increase radial clearance.

Inventive Principle:

Principle #15Dynamics

2Temperature

If cooling air flow rate is increased to enhance thermal protection, then the temperature level of discs is reduced, but the thermal expansion increases and radial clearance increases

Engineering Contradiction:

Improveabsolute temperature level of discsVSAvoidthermal expansion and radial clearance

Core Design Contradiction:

TemperatureVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by using flow rate control means to dynamically adjust the cooling air flow rate based on operating conditions. This allows the system to optimize the balance between reducing temperature for thermal protection and controlling thermal expansion to maintain stable radial clearance, rather than using excessive fixed cooling that would cause excessive expansion.

Inventive Principle:

Principle #35Parameter changes

3Duration of action of stationary object

If cooling air is supplied to cool the turbine, then the lifetime of discs is improved, but the performance of the turbomachine is reduced due to increased radial clearance

Engineering Contradiction:

Improvelifetime of turbine discsVSAvoidperformance of turbomachine

Core Design Contradiction:

Duration of action of stationary objectVSProductivity

Solution Approach 1:

The patent applies local quality by providing different cooling zones within the cavity: a radially inner zone for direct disc cooling and a radially outer zone for thermal management. By locally directing cooling air to specific areas rather than uniformly cooling the entire disc, the system achieves thermal protection while minimizing excessive radial clearance that would reduce performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements dynamics through flow rate control means that actively regulate the amount of cooling air supplied to the cavity. This dynamic control allows the system to adapt the cooling intensity based on operating conditions, maintaining optimal balance between thermal protection and performance requirements without fixed, excessive cooling that would increase radial clearance.

Inventive Principle:

Principle #15Dynamics

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 system achieves a balance between cooling requirements and performance by actively controlling airflow to maintain acceptable operating conditions and reduce radial clearance at the vane tip.

Implementation Method 1

a supply circuit (32) for supplying cooling air to the radially inner annular cavity (68)

Methodology Applied

Scientific EffectForced Convection: Forced Convection

Implementation Method 2

the introduction of cooling air greatly reduces the absolute temperature level of the disc

Methodology Applied

Scientific EffectThermal Conduction: Conduction (thermal)

Implementation Method 3

the turbine further comprising means for controlling the flow rate of supply air to said orifices of said inner and outer annular rows of orifices

Methodology Applied

Scientific EffectValve Flow Control: Valve

Data Source

PatentUS12366165B2Turbine

Publication Date: 2025.07.22 SAFRAN AIRCRAFT ENGINES SAS

AI summary

A turbine for a turbomachine of longitudinal axis including an alternating arrangement of annular rows of movable blades and of fixed blades and a radially inner annular cavity formed radially inside the movable and fixed blades, and a supply circuit for supplying cooling air to the inner annular cavity, the downstream end of the supply circuit comprising an inner annular row of orifices and an outer annular row of orifices opening into the radially inner annular cavity. The turbine may also include means for controlling the flow rate of supply air to the orifices of the inner and outer annular rows of orifices.