Gas Turbine Combustor Bulkhead Heat Shield Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The bulkhead in gas turbine engines is prone to damage from extreme high temperatures due to exposure to hot combustion gases, necessitating an effective cooling solution.
Innovation Solution
A heat shield with a back surface featuring effusion holes, radial ribs, and pin arrangements that direct and accelerate cooling air flow to enhance heat transfer and distribute temperature evenly, including specific configurations such as diamond and chevron formations, and raised trip strips to optimize cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the bulkhead is exposed to hot combustion gases to perform its function, then the combustor can operate, but the bulkhead is damaged by extreme high temperatures
Solution Approach 1:
A heat shield is introduced as an intermediary component between the hot combustion gases and the bulkhead. The heat shield includes a cooling airflow passage that directs cool air across the bulkhead surface, and a distal surface that faces the combustion chamber. This intermediary structure protects the bulkhead from direct thermal exposure while allowing the combustor to operate normally.
Solution Approach 2:
The invention utilizes pneumatic cooling by introducing cool air through a cooling airflow passage. The cool airflow is directed across the bulkhead surface to remove heat, leveraging fluid dynamics to achieve thermal protection. The system uses pressure differential to drive the cooling airflow from the inlet port through the passage and across the bulkhead.
2Temperature
If cooling airflow is directed across the bulkhead surface, then heat transfer is enhanced, but the complexity of the bulkhead assembly increases
Solution Approach 1:
The heat shield serves multiple functions: it protects the bulkhead from thermal exposure, directs cooling airflow across the bulkhead surface, and provides a structural barrier between the combustion chamber and the bulkhead. By combining these functions into a single component, the design avoids adding separate cooling systems that would increase complexity.
Solution Approach 2:
The heat shield is designed as a thin-walled structure with a cooling airflow passage integrated into its geometry. This thin-film approach allows the cooling function to be incorporated without adding significant bulk or complexity to the assembly. The passage is formed as part of the heat shield structure rather than as a separate component.
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 solution effectively cools the bulkhead by directing and accelerating cooling air flow, achieving isothermal temperatures and improving durability and part life by minimizing cooling flow requirements and enhancing heat transfer.
Implementation Method 1
a plurality of effusion holes extending from the back surface to the front surface of the panel
Implementation Method 2
directing and accelerating cooling air flow, achieving isothermal temperatures and improving durability
Implementation Method 3
radial ribs, and pin arrangements that direct and accelerate cooling air flow to enhance heat transfer
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A heat shield is disclosed. The heat shield may comprise a body having a back surface and an opposite front surface, wherein an opening in the body communicates through the front and back surfaces. The heat shield may further comprise at least one radial rail disposed on the back surface and extending radially outward from the opening for directing cooling air flow.