![]() ![]() For the sake of convenience in carrying out investigations for performance improvement in tubular heat exchangers, the analysis is usually carried out by selecting only one circular tube as a common practice as seen in several investigations carried out in the past (Dang & Wang, 2021 Deshmukh & Vedula, 2014 Nakhchi & Esfahani, 2019 Salem et al., 2017 Sheikholeslami et al., 2016 Wijayanta et al., 2020). Tubular heat exchangers are among the commonly used heat exchangers which consists of several circular tubes across which the heat energy exchange is carried out. Moreover, increased operational efficiency of such systems also aid in the development of compact systems that in turn reduce its cost as well as installation space requirements (Mousa et al., 2021).Ī wide variety of heat exchangers are in use depending on the type of application and heat loads. Hence, the efficacy with which heat transfer takes place in such thermal systems plays a huge role in achieving precious energy savings. ![]() All these sectors make use of energy transport systems such as heat exchangers which transfers energy in the form of heat from one side of the system to the other side to carry out the process such as in a refrigeration system, air-conditioning system, waste heat recovery device, chemical reactors, steam generators, power generation systems etc. Hence, most of the energy demands are still met through conventional energy sources such as oil and gas for applications related to transport, industry, residential and commercial sectors. However, the world is not yet completely ready in extracting renewable energy for all their energy needs owing to the technological limitations of existing renewable energy systems. However, the TEF increases with decreasing pitch distance of inserts and the overall TEF is found to be in the range of 0.86–1.19.Įnergy security is at the core of every nation’s future energy strategy and are predominantly based on renewable energy utilization. The thermal enhancement factor (TEF) is found to decrease with increasing flow attack angle and aspect ratio for all flow rates considered in the study. The maximum rise in Nusselt number and friction factor is about 2.1 times and 6.34 times higher than plain tube, respectively, for P = 30 mm. On the other hand, the pitch distance of insert significantly affects both heat transfer and friction factor. However, both parameters affect the friction factor significantly. ![]() The influence of aspect ratio on heat transfer is found to be more significant than that of flow attack angle. In addition, the presence of flow impingement effect on the upstream side and flow reattachment zones on the downstream side of vortex generator is found to contribute to enhanced heat transfer. The vortex generators produce strong longitudinal vortices which intensifies fluid mixing near the tube wall region thereby augmenting the heat transfer to the flowing air stream. The numerical results reveal that the presence of semi-elliptical vortex generator has significant influence on both Nusselt number and friction factor characteristics of circular tube. ![]() The study makes use of computational fluid dynamics methodology and the influence of varying aspect ratio (AR = 1, 2, 4 and 6), flow attack angle (45°, 60°, 75° and 90°) and longitudinal pitch (P = 30 mm, 60 mm and 90 mm) of vortex generator is investigated for the turbulent flow Reynolds number regime of 8000–26000. This article presents the heat transfer and friction factor characteristics of circular tube fitted with an array of novel semi-elliptical vortex generator inserts using air as working fluid. ![]()
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