What is the purpose of the fishmouth seals?

The purpose of fishmouth seals is primarily to protect against excessive leakage of hot combustion gases. These seals play a critical role in ensuring the integrity of the gas path within the combustion chamber and around the turbine. By effectively sealing the areas where components join, fishmouth seals help to contain the high-temperature gases produced during combustion, preventing them from escaping into unwanted areas. This containment enhances the overall efficiency of the turbine system since it allows the gases to expand and do work on the turbine blades effectively, maximizing energy extraction and maintaining optimal operational conditions.

While fuel efficiency, cooling of the combustion chamber, and emission reduction are important factors within gas turbine systems, they are not the direct purposes of fishmouth seals. The functioning of these seals is crucial for maintaining the operational parameters and safety of the system by preventing hot gases from leaking, which could lead to increased wear or damage to nearby components, as well as potential safety hazards.