The advantages of usingmultiple surrogates for approximation and reduction of helicopter vibration are studied. Multiple approximation methods, including a weighted-average approach, are considered so that pitfalls associated with only using a single best surrogate for the rotor blade vibration-reduction problem are avoided. A vibration objective function corresponding to a flight condition in ...

Title of thesis: EXPERIMENTAL INVESTIGATION OF A QUAD-ROTOR BIPLANE MICRO AIR VEHICLE Christopher Michael Bogdanowicz Master of Science, 2015 Thesis directed by: Dr. Inderjit Chopra Department of Aerospace Engineering Micro air vehicles are expected to perform demanding missions requiring efficient operation in both hover and forward flight. This thesis discusses the development of a hybrid air...

In order to harness the kinetic energy of marine currents, we propose a novel ocean-current turbine with a horizontal axis. The turbine can be moored to the seabed and function similarly to kites in a water flow. To operate such turbines in a marine current, the resulting rotor torque needs to be canceled. Therefore, the proposed turbine is designed with a float at its top and a counterweight a...

The paper presents a detailed review of the state-of-the-art research activities on structural reliability analysis of wind turbines between the 1990s and 2017. We describe the reliability methods including the firstand second-order reliability methods and the simulation reliability methods and show the procedure for and application areas of structural reliability analysis of wind turbines. Fur...

In this thesis, a permanent-magnet assisted synchronous reluctance machine (PMSynRel) design is presented for a plug-in hybrid electric vehicle application. Apart from operating as a traction machine to propel the vehicle, the machine is also used when the vehicle’s battery is charged from the grid. This additional functionality puts restraints (that are discussed in the thesis) on the final ma...

New wind turbine technologies and designs are being explored in order to reduce the cost of energy from offshore farms. Two potential routes a lower X- Rotor Concept (XRC) Multi-Rotor System (MRS) turbines. A key saving for both Novel concepts included this paper is operation maintenance (O&M) costs savings. The major component replacement conventional horizontal axis, XRC MRS turbines examined...

In this paper we present a tilting micro mirror with a large mirror surface of up to 2.5 mm x 1.0 mm and a large rotation angle of +/10° as needed for optical projection displays. The mirror is driven by vertical comb-drive actuators which are realized by a combination of deep reactive ion etching (DRIE) and a buried mask to provide selfalignment of the stator and rotor fingers in a silicon on ...

Induction machines are perhaps the most widely used of all electric motors. They are generally simple to build and rugged, offer reasonable asynchronous performance: a manageable torque-speed curve, stable operation under load, and generally satisfactory efficiency. Because they are so widely used, they are worth understanding. In addition to their current economic importance, induction motors ...