A multichannel dynamic-range compressor system using digital frequency warping is described. A frequency-warped filter is realized by replacing the filter unit delays with all-pass filters. The appropriate design of the frequency warping gives a nonuniform frequency representation very close to the auditory Bark scale. The warped compressor is shown to have substantially reduced group delay in ...

For a given linear compressor, the geometric configuration of the PTR (pulse tube refrigerator) affects the dynamic behavior of the linear compressor as well as the cooling performance of the PTR. The geometric configuration of each component precisely determines the flow impedance which contains the flow resistance, the inertance effect, and the compliance effect. In this paper, several simula...

In contrast to the conventional rotational compressors, the linear compressor is driven by a linear motor directly coupled with a piston. So the performance of the linear compressor is strongly dependent on the characteristics of the linear motor. In addition to high efficiency, the parameters of a linear motor should be nearly constant regardless of the amount of the current flow and position ...

Aquasi-three-dimensional multigrid Navier–Stokes solver on singleandmultiple-passage domains is presented for solving unsteady  ows around oscillating turbine and compressor blades. The conventional direct store method is used for applying the phase-shifted periodic boundary condition over a single blade passage. A parallel version of the solver using the message passing interface standard is ...

An unsteady two-dimensional numerical investigation was performed on the viscous flow passing through a multi-blade cascade. A Cartesian finite-volume approach was employed and it was linked to Van-Leer's and Roe's flux splitting schemes to evaluate inviscid flux terms. To prevent the oscillatory behavior of numerical results and to increase the accuracy, Monotonic Upstream Scheme for Conservat...

In recent years, several research activities have been conducted to develop knowledge in analysis, design and optimization of compressor anti-surge control system. Since the anti-surge control testing on a full-scale compressor is limited to possible consequences of failure, and also the experimental facility can be expensive to set up control strategies and logic, design process often involves...

The forced vibration of the 2D NASA flutter compressor cascade is numerically simulated in full scale with parallel computation technique. The compressor cascade consists of 9 blades bounded by 2 wind tunnel side walls. The implicit line Gauss-Seidel iteration with dual time stepping is employed. The turbulence is modeled with the Baldwin-Lomax model. A newly developed high resolution efficient...

The effects of compressor aerodynamic parameters, such as pitch-chord ratio, aspect ratio, and fillet, on the cascade performance have been studied in this paper. Slot configuration at the root of the blade has been proved to be an efficient passive control method for the corner separation control in compressor cascade. The combined effects of the pitch-chord ratio, aspect ratio, and blade fill...