Combustor Heat Shield Effusion Aperture Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine engine combustors face challenges with high thermal stresses in quench aperture grommets and heat shields due to high temperatures, leading to inefficiencies and potential degradation.
Innovation Solution
The design incorporates a multi-walled combustor structure with cooling cavities and effusion apertures that direct cooling air to impinge on the heat shield, forming an air blanket to reduce thermal stresses and improve thermal management, while optimizing the geometry of effusion apertures and quench apertures for efficient air distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling cavities and effusion apertures are used to cool the heat shield, then thermal protection is improved, but device complexity increases
Solution Approach 1:
The heat shield incorporates effusion apertures (porous structure) that allow cooling air to pass through and form a protective air blanket on the outer surface. This porous configuration enables effective thermal protection by distributing cooling air across the heat shield surface, reducing thermal stresses without requiring additional complex cooling systems.
Solution Approach 2:
The cooling system utilizes pneumatic principles by introducing cooling air through impingement apertures and effusion apertures. The cooling air flows through the cooling cavities and exits via effusion apertures to form a protective air blanket, utilizing fluid dynamics to achieve thermal protection. The air flow management through multiple aperture types creates an effective cooling regime.
2Stability of the object's composition
If quench aperture grommets are used to define quench apertures, then sealing and structural integrity are improved, but thermal stress resistance deteriorates due to high temperatures
Solution Approach 1:
The cooling system applies local quality by directing cooling air specifically to regions experiencing high thermal stresses, such as the quench aperture grommets and heat shield areas. The effusion apertures are strategically positioned to provide localized cooling where thermal stresses are most severe, rather than uniform cooling throughout the entire structure.
Solution Approach 2:
The cooling air is introduced in advance through the cooling cavities and effusion apertures to establish a protective air blanket before the hot combustion gases reach the heat shield and grommets. This preliminary cooling action prevents excessive temperature rise and thermal stress accumulation in the quench aperture grommets.
3Temperature
If multiple aperture types (impingement and effusion) are implemented, then cooling effectiveness is improved, but manufacturing complexity increases
Solution Approach 1:
The cooling system is segmented into distinct functional components: impingement apertures for introducing cooling air, cooling cavities for air flow distribution, and effusion apertures for forming the protective air blanket. This segmentation allows each component to be optimized independently while maintaining overall cooling effectiveness, and facilitates modular manufacturing approaches.
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 enhances thermal protection, increases turbine engine efficiency, and reduces emissions by effectively managing thermal stresses and air flow within the combustor.
Implementation Method 1
cooling air to impinge on the heat shield, forming an air blanket to reduce thermal stresses
Implementation Method 2
forming an air blanket to reduce thermal stresses
Implementation Method 3
cooling air to impinge on the heat shield
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An assembly is provided for a turbine engine. A combustor wall of the turbine engine assembly includes a shell and a heat shield. The combustor wall defines a quench aperture through the shell and the heat shield. The heat shield defines an effusion outlet a distance from the quench aperture equal to between about twenty-five times and about seventy-five times a width of the effusion outlet.