Advances and Outlooks of Heat Transfer Enhancement by Longitudinal Vortex Generators

TL;DR

This paper reviews the development, applications, and future prospects of longitudinal vortex generators (LVG) as a technique for enhancing heat transfer in various heat exchanger configurations since the 1990s.

Contribution

It provides a comprehensive overview of LVG research, including recent advancements, applications in different heat exchanger types, and future research directions.

Findings

LVG significantly improve heat transfer efficiency.

Applications include plate, wavy fin-and-tube, and oval-tube heat exchangers.

Future trends focus on optimizing LVG design and integration.

Abstract

In the last several decades, heat transfer enhancements using extended surface (fins) has received considerable attentions. A new heat transfer enhancement technique, longitudinal vortex generators (LVG), has received significant attention since the 1990s. It is activated by a special type of extended surface that can generate vortices with axes parallel to the main flow direction. The vortices result from strong swirling secondary flow caused by flow separation and friction. The state-of-the-art on research and applications of LVG are described here. The topical coverage includes heat transfer enhancement in straight channels and in heat exchangers. Among the latter are plate and wavy fin-and-tube heat exchangers, fin-and-oval-tube heat exchangers, and fin-and-tube heat exchangers with multiple rows of tubes. The trends and future directions of heat transfer enhancement by means of LVG are discussed.