In this paper a new geometry of circularly polarized patch antenna is proposed with improved bandwidth. The radiation performance of proposed patch antenna is investigated using IE3D simulation software and its performance is compared with that of conventional circular patch antenna. The simulated return loss, axial ratio and impedance with frequency for the proposed antenna are reported in thi...

Modeling and control for axial ow compression systems have received great attention in recent years. The objectives are to suppress rotating stall and surge, to extend the stable operating range of the compressor system, and to enlarge domains of attraction of stable equilibria using feedback control methods. The success of this research eld will signiicantly improve compressor performance and ...

This paper presents an element of a 2×2-element array antenna for Inmarsat BGAN/GPS applications. The element is an axial mode printed quadrifilar helical antenna that has been integrated with a compact feed network to provide sequential phase rotation for circular polarization (CP) radiation. The novel integrated lumped-element feed network is designed to provide a balanced RF power to the fou...

This study experimentally and numerically investigates motor cooling performance. The motor consists of a centrifugal fan, two axial fans, a shaft, a stator, a rotor and a heat exchanger with 637 cooling tubes. The pressure rise-flow rate (P-Q) performance curves of the cooling fans at 1800 rpm are tested using a test apparatus complying with the Chinese National Standard (CNS) 2726. Compared w...

surge and rotating stall phenomena are two dynamic instabilities that occur in both axial and centrifugal compressors. surge is the stream instability phenomenon in compressor that imposes severe damages to the compressors. nowadays, suppressing surge phenomenon is one of the most important issues in oil and gas industries, especially when flow reduction or gas reflux is considered. this resear...

the mass transfer performance of a pulsed disc and doughnut column for extraction of samarium and gadolinium from aqueous nitrate solution with d2ehpa was investigated. the effects of operating parameters such as pulsation intensity, continuous and dispersed phase velocities on column performance were investigated. the axial dispersion model was used to obtain the overall mass transfer coeffici...

in this study, first energy absorption of axial and bending loading is considered. next, thin walled structures under oblique loading are investigated using abaqus computer simulation, where 180 different cases are simulated. simulation results of the thin walled structures under oblique loading were compared with the experimental results of nagel, and good agreement was perceived. simulation r...

in this research paper, the performance of an air-cored axial flux permanent magnet synchronous generator is evaluated for low speed, direct drive applications using 3d finite element modeling and experimental tests. the structure of the considered machine consists of double rotor and coreless stator, which results in the absence of core losses, reduction of stator weight and elimination of cog...