Claim Missing Document
Check
Articles

Found 2 Documents
Search

Stereolithography 3D printing for the investigation of acoustic focusing Febrinawarta, Burhan; Miasa, I Made; Widyaparaga, Adhika; Sucipto, Sucipto; Premiaji, Witnadi Dardjat
Journal of Engineering and Applied Technology Vol. 5 No. 1 (2024): (March)
Publisher : Faculty of Engineering, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jeatech.v5i1.71672

Abstract

In our environment, acoustic sound waves transform into undesirable noise when their intensity exceeds 100 dB, prompting a need for effective mitigation strategies. In recent years, there has been increasing interest in utilising sound/noise and acoustics for energy harvesting, especially for low-power electronic devices committed to clean renewable energy sources. Metamaterials, with a spotlight on metalens, are emerging as a promising solution for precise sound focusing and energy conservation. This study delves into the intricate process of fabricating metalens through Stereolithography (SLA) 3D printing, unravelling their acoustic focusing capabilities. Metalenses, equipped with intricately designed labyrinthine unit cells tailored for manipulating reflected wave phases, materialize through the precision of SLA 3D printing, forming a sophisticated multilateral structure. The experimental framework for acoustic focusing integrates essential components such as a waveguide, speaker array, metalens, acoustic foam, and a sound level meter. The resultant metalens, composed of 22-unit cells with diverse dimensions, distinctly demonstrate robust acoustic focusing capabilities. Calibration procedures are systematically applied to ensure uniformity of speaker array output and to create a carefully controlled acoustic environment. Sound level measurements clearly depict zones of mutually reinforcing resonance heights, while, conversely, there are also zones of mutually attenuating sound. The complex interplay of sound waves through the metalens, intricately guided by the design of the unit cells, decisively determines the degree of acoustic focus achieved. The SLA 3D printed metalens emerges as a compelling manifestation of effective sound concentration, poised for potential applications in the realm of acoustic energy harvesting. Nevertheless, the study's consequential findings beckon further scientific exploration, prompting an in-depth comprehension of the nuanced impacts of input frequency and potential heating phenomena.
Numerical study of a thermoacoustic refrigerator with different stack geometries Murti, Prastowo; Dwi Astuti, Wijayanti; Febrinawarta, Burhan; Putra Pratama, Arief
Journal of Engineering and Applied Technology Vol. 6 No. 02 (2025): (August)
Publisher : Faculty of Engineering, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jeatech.v6i02.85682

Abstract

This study examines the performance of a thermoacoustic refrigerator with various stack geometries as a potential eco-friendly alternative to conventional refrigeration systems that rely on chlorofluorocarbons (CFCs). Thermoacoustic refrigerators create a cooling effect using sound waves and environmentally friendly gases such as helium. The stack, a crucial component where energy conversion occurs, must be optimized to maximize cooling efficiency. However, no studies have previously investigated the impact of stack geometries under a uniform system configuration. Thus, this study aims to numerically evaluate how different stack geometries and materials affect the performance of thermoacoustic refrigerators while maintaining consistent system geometry and properties to ensure fair comparison. The research focuses on three types of stack geometries: parallel plate, ceramic honeycomb, and wire mesh screen. Using DeltaEC software, the performance of these stacks was analyzed with a constant hydraulic radius. The results show that the wire mesh screen stack provides the highest cooling power (330 W) and coefficient of performance (COP) of 0.81, outperforming the other geometries. These findings highlight the potential of optimized stack designs to improve the efficiency of thermoacoustic refrigerators, promoting their development as a sustainable cooling technology.