Air Riding Seal Technology for Advanced Gas Turbine Engines

Rotating-to-static seals are critical components of all gas turbine engines. The seals can significantly affect the efficiency, operability, and durability of a gas turbine engine. As such, any improvements to these seals are highly desirable. Improvements may come in the form of reduced leakage and/or improved seal durability. The Air Riding Seal technology is a rotating-to-static seal that reduces leakages without contacting the rotor thereby increasing the performance and durability of the machine. The seal uses a hydrostatic balance of forces to maintain very small clearances between the rotor and stator sustaining low leakage. The phase I project addressed the feasibility of the concept through laboratory testing and an analysis match to the test data. It was shown that seal clearances can be reduced by an order of magnitude over the industry standard labyrinth seals and be reliably predicted with analysis models. The phase II project will build upon the success of the phase I project by testing the seal to capture real world anomalies and addressing seal performance in simulated engine conditions. Detailed analysis models will be created and anchored to test data then used to predict performance for specific engine applications. Commercial Applications and Other Benefits: It is shown that applying the Air Riding Seal technology to a utility-scale industrial gas turbine can reduce leakage by over 2.5%, increasing the power output of the machine by over 5.5% or reducing the fuel burn 1.25%. At todays energy rates this attributes to $7.2 million in increased annual revenue for each operating unit. Commercial application of this technology is not limited to industrial gas turbine engines. It has the potential to be applied to any machinery with rotating-to-static seals such as pumps for the oil and gas industry, super critical CO2 power cycles, aircraft engines, and turbopumps.