What is the purpose of carbon seals in turbine engines?

The purpose of carbon seals in turbine engines is primarily to act as rotor shaft bearing oil seals. These seals are designed to prevent oil from leaking out of the bearings and to inhibit the entry of contaminants, such as dirt and debris, into the bearing compartments. Carbon seals are particularly useful because they can withstand the high temperatures and pressures found within turbine engines while providing an effective barrier.

In addition to their sealing capabilities, carbon seals also contribute to the overall efficiency of the engine by maintaining the necessary oil supply for lubrication and cooling of the rotor bearings. By keeping the oil contained, carbon seals help ensure that the engine operates smoothly and reliably, reducing wear and tear on critical components.

The other options focus on functions that carbon seals do not perform. For example, carbon seals are not used to seal fuel injectors or limit airflow in the combustor, nor do they provide structural support for turbine blade attachment. Each of these functions is managed by different components designed specifically for those purposes.