Heat exchangers are considered essential parts in many industrial applications. The construction process for heat exchangers is completely complex because accurate measurements of the penalty of pressure-drop and the rate of heat transfer are needed. Designing a compact heat exchanger with a high heat transfer rate, while utilizing the least amount of pumping power, is the main design challenge. The most recent investigations (including experimental results, numerical models, and analytical solutions) in the field of circular tube heat exchangers in general, and twisted tapes and wire coils in particular, are covered in this review article, which has more than 90 references. The enhancement techniques in heat exchangers tubes can generally be separated into three groups: active, passive, and hybrid (compound) approaches. This article reviews the literature on advancements made in passive enhancement approaches, with a specific focus on two types of passive promoters that employ twisted tapes and wire coils. The main contribution of this research is to highlight the behavior and structure of fluid flow and the heat transfer features for the twisted tapes and the wire coils. It also explains how these passive promoters can be used in circular tube heat exchangers to improve hydrothermal performance. Where, the installation of wire coils and twisted tapes considerably alters the flow pattern and aids in the improvement of heat transfer. Where, comprehending the behavior of fluid flow is crucial and contributes to the enhancement of heat transfer. Twisted tapes are less effective in turbulent flow than wire coils because they obstruct the flow, which results in a significant pressure reduction. When it comes to turbulent flow, the thermohydraulic performance of twisted tapes is lower to that of wire coils.
Numerous inserts types are employed in different heat transfer improvement application devices. In this review study is forced on various types of twisted tape inserts in heat exchanger pipe. Geometrical configurations of twisted tape for example twist direction; length, width, space, twist ratio etc. were highly effect on flow pattern, hydrodynamic flow and heat transfer performance. In this review study observed that using different types of twisted tapes can improve thermal performance and hydrodynamic as compared to smooth pipe (without twisted tape). The review investigations found that improvement of thermal performance happens owing to decrease in pipe cross area, leads to rise in mixing flow, turbulence flow intensity flow and rise in swirl flow established through different kinds of twisted tapes. This article dealt with investigations pub-lished in corrugated pipes with varying field applications to provide good information for engi-neers and designers whom dealing and concerning with improvement of heat performance in heat exchanger corrugated pipes.