Thermal-Fluid Systems

Modeling and Performance Analysis of the Fuel System in an Aircraft Gas Turbine Engine

The fuel system in an aircraft gas turbine engine supplies fuel to the combustor and manages the temperature of both lubricating oil and fuel. It also provides hydraulic power to actuators, such as variable stator actuators and variable bleed valves. Since the fuel system directly affects engine performance and control, its reliability is a critical concern. In this study, the fuel system—including the fuel pumping/metering units and the fuel-oil heat exchanger—was modeled using the commercial system software AMESim. Variations in thermal and fluid properties according to flight conditions were then investigated to assess performance during the preliminary concept design process. 

Liquid Transport and Atomization of a Rotary Atomizer in a Gas Turbine Engine

A rotary atomizer transports fluid from the internal reservoir to the outside of the disk using centrifugal force. The liquid ejected by this device disperses in various forms, such as droplets, jets, ligaments, or thin film. The rotary atomizer can effectively supply atomized fuel into a slinger-type combustor without requiring a high-pressure source. However, this device has two major concerns: fuel atomization and transport. Poor atomization may occur when the nozzle rotates at low speed, deteriorating ignition performance and causing combustion instability. Non-annular flow modes in the rotating pipe can lead to uneven fuel distribution along the circumference, resulting in localized hot spots in the combustor. To address these issues, experimental studies were conducted to investigate liquid behavior both inside and outside the rotary slinger atomizer.