Foreign-object damage associated with the ingestion of debris into aircraft turbine engines can lead to a marked degradation in the high-cycle fatigue (HCF) life of turbine components. This degradation is generally considered to be associated with the premature initiation of fatigue cracks at or near the damage sites; this is suspected to be due to, at least in part, the impact-induced residual...

Full-scale numerical prediction of the aerothermal flow in gas turbine engines are currently limited by high computational costs. The approach presented here intends the use of different specialized flow solvers based on the Reynolds-averaged Navier-Stokes equations as well as large-eddy simulations for different parts of the flow domain, running simultaneously and exchanging information at the...

MIT is developing micro-electro-mechanical systems (MEMS)-based gas turbine engines, turbogenerators, and rocket engines. Fabricated in large numbers in parallel using semiconductor manufacturing techniques, these engines-on-a-chip are based on micro-high speed rotating machinery with power densities approaching those of their more familiar, full-sized brethren. The micro-gas turbine is a 2 cm ...

T o d a y ’s control systems have their roots, to a great extent, in the speed control of driving engines (prime movers) and particularly in the speed control of water turbines. The first turbines with automatic speed control appeared sometime in the mid-19th century. In this column, I discuss the history of water-turbine control systems, noting the older inventions and techniques that made pos...

Thermal barrier coatings (TBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. Infrared Thermography method has been selected for obtaining thermal images and studying the TBCs of Alumina, Zirconia and Alumina+Titanium oxide coated on the base plate of Titanium, by measuring the back wall temperature...

There is a continuous search for an alternative oxide material to the yttria-stabilized zirconia (7YSZ), which currently serves as the thermal barrier coating materials for turbine engines [1]. The new material should have low thermal conductivity, high temperature stability, and ferroelastic toughening as exhibited by the 7YSZ. Therefore in this study, the Y-Ta-Zr-O system was investigated. Th...

Recent advances in the field of silicon micro-fabrication techniques and silicon-based Microelectromechanical Systems (MEMS) have led to the possibility of a new generation of micro heat engines for power generation and micro air-vehicle propulsion applications. The design for a silicon-based, micro gas turbine generator capable of producing 10-50 Watts of power in a volume less than 1 cm3 whil...

KIVA is a widely used (;ode for combustion simulation in engines. We discuss its shortcomings in approximating real gas turbine combustors and what might be done to improve its performance. It is assumed that the combustion and CFD phenomena are modeled with complete accuracy and that the solution of discretized versions of these models is also accurate. Thus the focus is on the geometry, grid ...

The deposition of mineral debris in the turbine sections of various jet engines occurred after operation on Middle-East routes. Plasma sprayed Zr02-Yn03 thermal barrier coatings were aged with sand samples from several Middle-East locations at temperatures of 1200 to 1500 OC. At temperatures above 1400 OC, the molten sand formed glassy silicate debris that penetrated the ceramic coating complet...

For the preliminary design and the off-design performance analysis of axial flow turbines, a pair of intermediate level-of-fidelity computer codes, TD2-2 (design; reference 1) and AXOD (off-design; reference 2), are being evaluated for use in turbine design and performance prediction of the modern high performance aircraft engines. TD2-2 employs a streamline curvature method for design, while A...