Studs with Integrated Cooling Channels for Combustor Heat Shields
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cooling of heat shield panels around studs in gas turbine combustors is challenging, particularly in smaller designs, leading to potential hot spots due to limited space for cooling air flow and blockage by washers, which can compromise the structural integrity of the studs.
Innovation Solution
Incorporating a channel or slot in the peripheral surface of studs that extends from the inlet end connected to a cooling air source to the air gap between the heat shield panel and the combustor shell, allowing directed cooling air flow to reach the base of the studs, thereby enhancing cooling efficiency and preventing hot spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If heat shield panels are mounted with studs to the combustor shell, then the heat shield provides better protection to the combustor, but the cooling of panel areas around the studs becomes challenging leading to hot spots
Solution Approach 1:
The cooling channel is integrated directly into the stud structure, merging the fastening function with the cooling function. The channel extends through the stud from the rear face to the forward face, allowing cooling air to be delivered directly to the critical stud root area that was previously difficult to cool.
Solution Approach 2:
The cooling channel is specifically positioned to target the local hot spot area around the stud roots. The channel outlet on the forward face of the stud directs cooling air precisely where needed - at the stud base and surrounding panel area - providing localized cooling quality rather than general cooling.
2Volume of moving object
If smaller sized heat shield panels are used, then the combustor design is more compact, but the cooling of areas around the studs becomes even more challenging
Solution Approach 1:
The cooling channel utilizes the vertical dimension of the stud by extending from the rear face through the stud body to the forward face. This vertical arrangement allows cooling air to traverse the full height of the stud, delivering cooled air to the critical root area without requiring additional horizontal space, thus maintaining compact combustor volume.
Solution Approach 2:
The stud serves dual purposes - structural fastening and cooling air delivery. By integrating the cooling channel within the stud itself, the design eliminates the need for separate cooling components that would increase volume, allowing compact panel design while maintaining effective cooling.
3Strength
If washers are used with the studs for mounting, then the mounting is more secure, but the washers block cooling air flow to the stud base
Solution Approach 1:
The cooling channel acts as an intermediary pathway that bypasses the washer obstruction. Cooling air enters the channel at the rear face of the stud, travels through the stud body via the internal channel, and exits at the forward face, effectively using the stud itself as a mediator to deliver cooling air past the blocking washer to the critical stud root area.
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 directed cooling air flow through the channel or slot effectively reduces the risk of hot spots and maintains the structural integrity of the studs by ensuring adequate cooling, even in constrained spaces, improving the durability and performance of the heat shield panels.
Implementation Method 1
a channel extending along the at least one stud from an inlet end at the stud distal end connectable to a source of cooling air outside of the combustor shell to an outlet end disposed so as to communicate with the air gap
Data Source
AI summary
A combustor heat shield for a gas turbine engine has a heat shield panel adapted to be mounted to an inner surface of a combustor shell with a back face of the panel spaced-apart from the combustor shell to define an air gap therewith. Studs project from the back face of the panel for engagement in corresponding mounting holes defined in the combustor shell. Each stud has a threaded distal end portion for engagement with a nut outside of the combustor shell. At least one of the studs has a channel defined in a peripheral surface thereof. The channel extends longitudinally along the stud from an inlet end connectable to a source of cooling air outside of the combustor shell to an outlet end disposed within the air gap for locally providing cooling air at the base of the stud.