Tip leakage loss introduces major part of losses of the rotor in axial gas turbines. Therefore, the rotor blade tip has a considerable effect on rotor efficiency. To understand the flow physics of the rotor tip leakage, we solve the flow field for different tip platforms (passive flow control) and by considering coolant tip injection (active flow control). Various blade tip configurations s...

This paper presents a Collision Resolution Algorithm which significantly improves the performance in terms of throughput and delay of the uplink contention channel existing in Wireless ATM MAC protocols such as MASCARA [9], where slotted ALOHA is employed. FS-ALOHA groups the requests arrived at the mobile terminals during a frame length and serves these groups on a FIFO basis using slotted ALO...

This paper presents the development of a multibody dynamics model of a VTOL teetering rotor. The developed model includes a teetering hub, containing a flexure and torque tube, rotor blades, pitch links, and swashplate system. A non-teetering rotor configuration, which modified the baseline teetering rotor by removing the teetering hinge, is also developed, and its aeromechanics characteristics...

In this paper, we characterize the rotational dynamics and observe rotor-rotor interactions within a crystalline, three-dimensional array of dipolar molecular rotors. The rotating portion of each rotor molecule consists of a dipolar fluorine-substituted phenyl group. The phenyl rotors are connected by acetylene linkages to bulky triphenyl methyl groups which are held rigid in the crystal lattic...

The compression process within screw compressors induces large pressure and temperature changes that cause the rotors to deform. To determine this effect, a 3-D numerical method has been developed to calculate flow and deformation simultaneously. This comprises a mathematical procedure to generate a numerical grid for both the solid and fluid domains, in the form of a computer program named SCO...

The THz transmission spectra of three trichloroanisole (TCA) compounds (2,3,4-TCA, 2,4,6-TCA and 2,5,6TCA) are measured using terahertz time-domain spectroscopy (THz-TDS). The spectrum of 2,4,6-TCA in the solid phase displays several discrete absorption peaks over frequency range from 0.1 to 1.5 THz, with significant peaks observed at 0.6, 0.95 and 1.2 THz. A weak absorption peak is observed ne...

The benefits of energy and operational cost savings from using copper rotors are well recognized. The main barrier to die casting copper rotors is short mold life. This paper introduces a new approach for manufacturing copperbar rotors. Either copper, aluminum, or their alloys can be used for the end rings. Both solid-core and laminated-core rotors were built. High quality joints of aluminum to...

The paramagnetic complex bis(oxazolinylphenyl)amine–Fe(III)Cl2 is investigated by means of solid-state proton NMR at 18.8 T (800 MHz) using magic-angle spinning at 65 kHz. Spin echoes that are excited and refocused by combs of rotor-synchronized pulses in the manner of ‘Delays Alternating with Nutation for Tailored Excitation’ (DANTE) allow one to characterize different chemical environments th...

experimental tests were performed to study the seismic behavior and performance ofmodified steel chevron braced frame systems, which incorporate a vertical slotted connection(vsc) detail between the top of the braces and the floor beam above. the vsc detail isintended to prevent vertical load transfer to the beam and limit brace forces to thecompressive resistance of the members. full-scale qua...

In this paper we present a new multiple access protocol based on DS-CDMA and slotted Aloha random access protocol with reservation for integrated voice and data transmission in packet personal communication networks (PCN). Speech activity detection is assumed for voice terminals who will relinquish their codes during their silence periods to be used by the data terminals. The code will be retur...