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Design optimization of a transonic compressor rotor (NASA rotor 37) using the response surface method (RSM) and three-dimensional Navier-Stokes analysis has been carried out in this work. The Baldwin-Lomax turbulence model was used in the ow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and a linear programming method was used to optimize the response surface. As a main result of the optimization, adiabatic ef ciency was successfully improved. It was found that the optimization process provides reliable design of a turbomachinery blade with reasonable computing time.

This study is intended to present a computational standard model for combustibles, compartments and buildings. As performance based design is more popular, fire-intensity and fire-load have turned out to be very important factors for building design and can be predicted through some computational work. To predict and estimate the fire properties of a residential fire, we made some numerical models of combustibles, compartments and a residential building. In a bid to validate the estimate values, research was divided into three parts of step verifications. The first was for combustibles, the second was for compartments and the third was for the building. During each step, computational analysis results from numerical models were compared with real fire tests. For computational analysis, the Fire Dynamics Simulator was used with Large Eddy Simulation model for turbulence. Consequently, fire-intensity was well predicted and flash-over of rooms were successfully estimated.

Design optimization of a transonic compressor rotor (NASA rotor 37) using the response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. The Baldwin-Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. It was found that the optimization process provides reliable design of a turbomachinery blade with reasonable computing time.

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A compact microstrip dual‐mode bandpass filter with inserted spur‐lines at the edge of the patch is proposed. In order to obtain a low insertion loss, the proposed filter has no coupling gaps. Also, it has a size reduction of about 45% at the same resonant frequency as compared conventional dual‐mode bandpass filters. Feed lines with offset are applied to ensure a minimal mismatch. From the measured results, the dual‐mode filter has a 0.58‐dB insertion loss at 1.27 GHz with 12% bandwidth. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 33–34, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20366

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handed material. However, in comparison to the SRR/wire structure presented in [1], in-band insertion losses are not as good. This is thought to be due to the lack of symmetry of the spiral resonators, which may give rise to some kind of undesired interaction between wires and spirals, resulting in band-pass degradation. In the SRR/wire CPW medium, this interaction was precluded by properly aligning wires and SRRs [4]. Nevertheless, the main relevant characteristics of SRs are their dimensions. Although combined with metal wires in CPWs, they cannot compete with SRRs in terms of circuit performance; it is very clear that, when coupled to a CPW to achieve a rejection-band structure, they are very promising. Similar performance to that obtained with SRRs coupled to a CPW has been demonstrated, but with the added advantage of lower dimensions for the same resonant frequency. CONCLUSIONIn conclusion, it has been demonstrated that spiral resonators can be used as constitutive elements in narrowband CPW stop-band and band-pass structures. In comparison to SRRs, the key advantage of spirals is miniaturization, where dimensions reduced by a factor of two are expected for the same resonant frequency, or, alternatively, the resonant frequency is reduced by the same factor if the dimensions are maintained, as has been shown in the paper. It has been demonstrated that, when coupled to CPWs, spirals are able to provide rejection levels in the vicinity of resonance comparable to those obtained with SRRs. In band-pass structures, where metal wires are added between the signal and ground, good frequency selectivity has been obtained, but with higher in-band insertion losses than those obtained with CPW and SRRs. Nevertheless, for the first time the potentiality of spiral resonators in the fabrication of metamaterial-based structures (including negative and left handed) in CPW technology has been pointed out. The results of this work are patent pending.