August 21, 2016

Stability Study of a Time-delayed Thermoacoustic System

  • Lei S.

In this paper, of primary concern is a time-delayed thermoacoustic system, viz. a horizontal Rijke tube. A continuation approach is employed to capture the nonlinear behavior inherent to the system. Unlike the conventional approach by the Galerkin method, a dynamic system is naturally built up by discretizing the acoustic momentum and energy equations incorporating appropriate boundary conditions using a finite difference method. In addition, the interaction of Rijke tube velocity with oscillatory heat release is modeled using a modified form of Kings law by Heckl. A comparison of the numerical results with experimental data and the calculations reported reveals that the current approach can yield very good predictions. Moreover, subcritical Hopf bifurcations and fold bifurcations are captured with the evolution of dimensionless heat release coefficient, generic damping coefficient and time delay. Linear stability boundary, nonlinear stability boundary, bistable region and limit cycles are thus determined to gain an understanding of the intrinsic nonlinear behaviors.

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Recent Publications

October 30, 2016

43 Years of Actors: a Taxonomy of Actor Models and Their Key Properties

The Actor Model is a message passing concurrency model that avoids common concurrency issues such as low-level data races and deadlocks by construction. This has made the Actor Model an interesting concurrency model that has been used in various concurrency settings both in research as well as in industry, ranging ...

October 01, 2016

Practical Hardware Considerations for the Design of Hybrid Precoding Systems

  • Rulikowski P.
  • Venkateswaran V.

In this paper we describe practical implications of employing communication schemes with analog beamforming networks (ABFN). Specifically, we formulate realistic constraints for standard ABFN based on the S-parameters of the hardware components involved in their implementation. We concentrate on flexible fully-connected ABFN and Butler networks for im- plementing the discrete ...

October 01, 2016

The hydrodynamic and heat transfer behaviour downstream of a channel obstruction in the laminar flow regime

  • Jeffers N.
  • Punch J.
  • Stafford J.
  • Waddell A.

Microfluidic systems have been proposed as potential solutions for the cooling of next-generation Integrated Circuits (ICs) and Photonics Integrated Circuits (PICs). For PICs, integration of microfluidics may enable greater laser-bar array densities and, consequently, greater transmission bandwidth. To cool the micrometer scale hot-spots produced by the laser-bars, a passively actuated ...