In this article, we suggested a novel design of polarization Splitter based on coupler waveguide on InP substrate at 1.55mm wavelength. Photonic crystal structure is consisted of two dimensional (2D) air holes embedded in InP/InGaAsP material with an effective refractive index of 3.2634 which is arranged in a hexagonal lattice. The photonic band gap (PBG) of this structure is determined using the plane wave expansion (PWE) method by RSOFT Bandsolve software. Band diagram also show an overlap of two photonic bandgaps for both TE and TM about 1.55 mm wavelength. Also, the band structure is calculated for a lattice constant of 625 nm and a radius of 266.6 nm. The proposed polarization Splitter has a transmission spectral of 75% and 70% for the TE and TM polarized light, respectively. The proposed polarization Splitter is realized in a standard semiconductor technology on InP substrate at 1.55 m wavelength and can be easily monolithically integrated with other planar integrated circuits.

The present study aims to describe characteristics of cavitation during the startup process of a condensate pump. The pump is featured by an impeller equipped with five Splitter blades. A computational fluid dynamics (CFD) work was conducted to plumb the evolution of cavitation in the pump. Effect of the volumetric flow rate on instantaneous cavitation patterns as the rotational speed of the pump increased was analyzed. The results show that high resistance to cavitation of the pump depends greatly on large area of the impeller eye, which is related to the deployment of the Splitter blades. The Splitter blades are insignificantly affected by cavitation. During the startup process, both the pump head and the pump efficiency vary drastically, which is insensitive to the flow rate. At a net positive suction head (NPSH) of 2. 0 m, high flow rates are responsible for intensified cavitation. High volume fraction of cavitation arises near the inlet of long blades. As the rotational speed increases, the evolution of cavitation is featured by intermittency and diversified cavity patterns. Furthermore, the sum of the volume fraction of cavitation fluctuates with continuously increasing rotational speed.

In this paper, we numerically simulated a glass-based all-optical 1×N power Splitter with eleven different configurations using soliton breakup in a nonlinear medium. It is shown that in addition to reconfigurability of the proposed Splitter, its power splitting ratio is tunable up to some extent values too. Nonlinear semivectorial iterative finite difference beam propagation method (IFD-BPM) with inclusion of two photon absorption (TPA) effects is applied to simulate the soliton propagation at different mode power. It is shown that operation of the proposed Splitter depends on input mode power and an all-optical reconfigurable-tunable functional device is designed with nonlinear optical (NLO) property of a simple structure.

In the wake of the bluff bodies rigid Splitter plates are known to control vortex shedding. In this study, the problem of flexible Splitter plate in the wake of circular cylinder was investigated using Particle Image Velocimetry (PIV) experimentally. In this case, the Splitter plate which has a certain amount of modulus of elasticity freely deforms along its length because of the fluid forces on plate. The diameter of cylinder, D was 60 mm while the Reynolds number based on the cylinder diameter is kept constant as 2500, the characteristics length of the control element, L was tested for four different cases that the values of L/D were 0, 1.25, 2.25, 2.5 in the investigation. As a consequence, turbulent kinetic energy, TKE, velocity vector field< V>, vortex<w>, Reynolds stress<u′v′>, root mean square of stream wise and transverse velocities, < urms>/U, <vrms>/U were analyzed. It is found that the variable parameter of L/D affects the flow structures and also noted that it decreased maximum level of all characteristic values.

This study investigates the effect of Splitter angles on the aerodynamic flow of two free streams under incompressible conditions. The angle of the Splitter is changed from 0 to 40° to simulate different wake structures on the slant. The convective Mach number was selected at 0. 185. The velocities at the upper surface (primary freestream) and lower surface (secondary freestream) are changed to generate two different cases. The simulation was conducted using steady generalized k-ω (GEKO) models with modification of mixing coefficients and large eddy simulation for transient flows. The results of numerical data were validated with experimental data with the same flow conditions. This study presents that when initial parameters are suitably selected, the numerical schemes provide sufficient accurate averaged results. For case 1, when the primary freestream is higher, the length of the mixing region increases with the Splitter angle. Additionally, the generation of the wake flow leads to movement upward of the mixing position for Splitter angles above 20°. For case 2, when the primary freestream is smaller, the mixing characteristics are little changed for different angles. The Proper Orthogonal Decomposition (POD) was applied for case 1 and the results showed that the pair of counter-vortices is the main dominant structure flow in the mixing region. The averaged flow fields, turbulent kinetic energy, and unsteady behavior were analyzed and discussed insight in this study.

In this paper, a 1*2 all-optical power Splitter has been presented which is suitable for the third window of optical communications based on photonic crystal structures. This structure can provide a 50% transmission coefficient at a wavelength of 1550 nm in each Splitter output branch. The device has been designed based on an input waveguide, two output waveguides, and an L4 resonant cavity in which the transmission coefficient of the structure is improved by infiltrating an optical fluid in some holes without any changes in the place and size of the radius of holes.