A measurement method presented by John R. Juroshek (NIST) in conjunction with the Vector Network Analyzers R&S ZVM or R&S ZVK from Rohde & Schwarz allows fast and accurate determination of the equivalent reflection coefficient of power splitters or directional couplers. If the magnitude and phase of reflection coefficients of source (e.g. power splitter) and sink (e.g. power meter) are known, a...

If the effects of fluid rotation are neglected, one-dimensional theory for a single actuator disc gives a maximum power coefficient of 16/27. This is the usual Betz limit for the power of horizontal-axis wind turbines. Tandem discs are a more appropriate representation for a vertical-axis, Darrieum, wind turbine and give more accurate predictions of turbine performance when used in conjunction ...

due to increasing expansion of energy consumption and also the decrease and tendency towardsending fossil energy reserves, the current energy cycle needs to use alternative energy speciallywind energy, because it’s considerably cheaper than other recycling sources. the presentresearch investigates suitable possibility of exploiting wind energy to create wind power stationin soltanieh zone of za...

The Savonius wind turbine is a type of vertical axis wind turbine (VAWTs) that is simply composed of two or three arc-type blades which can generate power even under poor wind conditions. A modified Savonius wind turbine with novel blade shapes is introduced with the aim of increasing the power coefficient of the turbine. The effect of blade fullness, which is a main shape parameter of the blad...

In this article, a time dependent partial differential equation is used to model the nonlinear boundary value problem describing heat transfer through a radial porous moving fin with rectangular profile. The study is performed by applying a numerical solver in MATLAB (pdepe), which is a centered finite difference scheme. The thermal conductivity and fin surface emissivity are linearly ...

The flow of a non-Newtonian, power-law fluid, directed normally to long, two-dimensional horizontal bodies, is considered in the present note. It is found that for low Reynolds numbers (Re ≤ 0.1) and a low power-law index (shear-thinning fluids) the drag coefficient always obeys the relationship cD = A/Re, whereas at a high power-law index (shear-thickening fluids) the drag coefficient tends to...

The fundamental concern of this article has been to apply the residual power series method (RPSM) effectively to determine of the unknown spacewise dependent coefficient in the time fractional heat equation in the Caputo sense with over measured data. First, the fractional power series solution of inverse problem of unknown spacewise dependent coefficient is obtained by residual power series me...

The FFT processor is a critical block in all multi-carrier systems used primarily in the mobile environment. The portability requirement of these systems is mainly responsible for the need of low power FFT architectures. This paper proposes a technique to reduce the power consumption of a popular low power radix-4 pipelined FFT processor by modi&ing its operation sequence. The complex multiplie...

This paper numerically investigates a 3D mesh independency study of a straight blade horizontal axis tidal turbine modelled using Computational Fluid Dynamics (CFD). The solution was produced by employing two turbulence models, the standard k-ε model and Shear Stress Transport (SST) in ANSYS CFX. Three parameters were investigated: mesh resolution, turbulence model, and power coefficient in the...