This paper describes the analysis and design of a class of square spiral microstrip antennas for broad frequency band and multi-frequency operations by adding suitable tuning elements in a single structure. The simulation and modeling of these configurations have been done using Ansoft HFSS software. The resonant frequencies and dimensions are computed from the cavity model of square patch. The...

We investigate the mixing properties of an acoustic driven flow in a parallelepipedic cavity with square basis. Relying on nonnormal reflections, beam path is obtained, generating global complex which enables chaotic advection. For moderate power source, region invades whole cavity, illustrating that streaming can be used successfully as nonintrusive tool to mix efficiently.

A wideband circularly polarized (CP) slot array with high radiation efficiency is proposed. The cavity-backed square slots are designed to achieve wideband CP radiation with a unidirectional pattern. The slotted waveguide is adopted to feed the array with high efficiency. The square slot, cavity and feeding slot in the waveguide can be viewed as a radiating element. A CP slot array can be conve...

a r t i c l e i n f o a b s t r a c t A two-dimensional double Multiple Relaxation Time-Thermal Lattice Boltzmann Equation (2-MRT-TLBE) method is developed for predicting convective flows in a square differentially heated cavity filled with air (Pr = 0.71). In this Letter, we propose a numerical scheme to solve the flow and the temperature fields using the MRT-D2Q9 model and the MRT-D2Q5 model,...

In the present study the problem of mixed convection flow in the presence of magnetic field in a lid-driven square cavity with internal heat generation or absorption and uniform heating of bottom wall were investigated numerically. The square cavity vertical walls are maintained at cold temperature while the upper wall is insulated. The physical problem is then expressed mathematically by a set...

In this research we have implemented the Random Vortex Method to calculate velocity fields of fluids inside open cavities in both turbulent and laminar flows. the Random Vortex Method is a CFD method (in both turbulent and laminar fields) which needs the Schwarz-Christoffel transformation formula to map the physical geometry into the upper half plane. In some complex geometries like the flow in...

The problem of free convection flow and heat transfer of a fluid inside a square cavity having adiabatic obstacle positioned in the center of the cavity has been investigated numerically using a penalty finite element method. Calculations have been made for Rayleigh numbers ranging from 10 to 10 for an obstacle of aspect ratios AR=0, 0.4, 0.5, 0.6. Nusselt number results are presented for Prand...