This work proposes a multi-objective optimization approach to model and optimize small scale standing wave thermoacoustic refrigerator (TAR). study aims the geometric variables namely stack position, length, blockage ratio plate spacing involved in designing refrigerators. Unlike most previous studies, these are considered interdependent. System parameters constraints that capture underlying dynamics have been used define models. The cooling load, coefficient of performance acoustic power...

Purpose – This paper aims to illustrate the use of augmented epsilon-constraint method implemented in general algebraic modelling system (GAMS), aimed at optimizing geometry a thermoacoustic regenerator. Thermoacoustic heat engines provide practical solution problem management where can be pumped or spot cooling produced. However, most inhibiting characteristic is their current lack efficiencies. Design/methodology/approach Lexicographic optimization presented as an alternative technique...

As a result of miniaturisation, electronic products are shrinking in size and weight but with greater pressure for cost reduction. Heat fluxes have increased considerably hence thermal management becomes crucial from the reliability point view. Thermoacoustic heat engines provide practical solution to problem microcircuits where they can be used pump or produce spot cooling specific circuit elements. However, most inhibiting characteristic thermoacoustic is its current lack efficiency. A...

The Stockbridge damper (tuned mass absorber) is used on overhead transmission power lines to suppress wind-induced vibrations. These get exposed various types of wind motions that cause them vibrate and this causes fatigue failure at the suspension clamp where maximum stress occurs. Aeolian vibration most common motion eventually, lines. This paper presents study an asymmetric damper. A set experiments were conducted according Institute Electrical Electronics Engineers (IEEE) 664 standards...

Nonlinear systems; vector-valued differential equations; higher order equivalent semi-analytical solutions

Second order vector-valued nonlinear differential equations occurring in science and engineering have been considered which generally do not closed-form solutions. Explicit incremental semi-analytical numerical solution procedures for multiple-degree-of-freedom systems developed. Higher equivalent were formulated then subsequent values of vectors updated using explicit Taylor series expansions. As the time-step tends to zero, displacement velocity are exact expansions involving as many...

SUMMARY We consider numerical solutions of nonlinear oscillatory systems where closed‐form do not exist. Such occur in buckling columns, electrical oscillations circuits containing inductance with an iron core, and vibration mechanical restoring forces. have improved the accuracy, stability, speed generalized Newmark scheme Zienkiewicz Taylor using one‐step multiple‐value algorithms. Previously, a Laplace transform‐based method was developed to determine initial conditions higher order...

This paper presents and discusses the investigation of an asymmetric Stockbridge damper that is used to suppress wind-induced vibrations on slender structures such as overhead transmission power lines. The lines vibrate because wind motion this causes fatigue failure usually at suspension clamp where maximum stress occurs. Experiments were conducted dampers according Institute Electrical Electronics Engineers (IEEE) 664 standards, results revealed produces four resonance frequencies. further...

Overhead power cables get exposed to wind motions that eventually cause oscillation and significant fatigue failure them. Aeolian vibration is one of the most common vibrations caused by high frequency low amplitude. Although other motion failures on transmission lines, account for a greater percentage these failures. Various devices have been developed, designed, implemented minimise lines. The Stockbridge damper standard dampers used. fundamental understanding asymmetric studied in this...

This work considered the experimental investigation of self-damping characteristics ACSR Beresford and TERN transmission line conductors using free forced vibration techniques. When subjected to a load, is power dissipated per unit length conductor as it vibrates. are two most commonly used in South African network. The paper has revealed that for all tests, damping factors on was ζ ≤ 0.0307, was, 0.057, whereas (forced vibration) were found be 0.0103, (free 0.056. obtained both...