Geng Chen

Bio: Geng Chen is an academic researcher from University of Auckland. The author has contributed to research in topics: Thermoacoustics & Thermoacoustic heat engine. The author has an hindex of 8, co-authored 12 publications receiving 187 citations. Previous affiliations of Geng Chen include University of Glasgow & Southeast University.

Multi-physics coupling in thermoacoustic devices: A review

Abstract: Latest developments in thermoacoustic devices have demonstrated comparable power output and efficiency, but higher reliability and lower cost when compared to conventional low-grade heat recovery technologies. A good coupling between multiple physical fields plays a pivotal role in realizing these potentials. This article provides a comprehensive review of the multi-physics coupling effects, namely, thermal-acoustic coupling, acoustic-mechanical coupling and mechanical-electric coupling, inside thermoacoustic devices including thermoacoustic engines, thermoacoustic electric generators, thermoacoustically-driven refrigerators, etc. The basic principles, operating characteristics, design strategies and future prospects are discussed individually for each coupling effect. System-level design techniques and synthetic optimization methodologies in consideration of the multi-physics coupling effects are presented. This review work gives insights into the underlying mechanisms of various coupling effects in thermoacoustic devices and provides guidelines for improvements of modern thermoacoustic technologies for low-grade thermal energy recovery, refrigeration and electric power generation purposes.

A review of energy harvesting using piezoelectric materials: state-of-the-art a decade later (2008–2018)

Abstract: Energy harvesting technologies have been explored by researchers for more than two decades as an alternative to conventional power sources (e.g. batteries) for small-sized and low-power electronic devices. The limited life-time and necessity for periodic recharging or replacement of batteries has been a consistent issue in portable, remote, and implantable devices. Ambient energy can usually be found in the form of solar energy, thermal energy, and vibration energy. Amongst these energy sources, vibration energy presents a persistent presence in nature and manmade structures. Various materials and transduction mechanisms have the ability to convert vibratory energy to useful electrical energy, such as piezoelectric, electromagnetic, and electrostatic generators. Piezoelectric transducers, with their inherent electromechanical coupling and high power density compared to electromagnetic and electrostatic transducers, have been widely explored to generate power from vibration energy sources. A topical review of piezoelectric energy harvesting methods was carried out and published in this journal by the authors in 2007. Since 2007, countless researchers have introduced novel materials, transduction mechanisms, electrical circuits, and analytical models to improve various aspects of piezoelectric energy harvesting devices. Additionally, many researchers have also reported novel applications of piezoelectric energy harvesting technology in the past decade. While the body of literature in the field of piezoelectric energy harvesting has grown significantly since 2007, this paper presents an update to the authors' previous review paper by summarizing the notable developments in the field of piezoelectric energy harvesting through the past decade.