Internal flow of TiO₂–CNT/water nanofluids in a twisted tape insert tube

Abstract

Hybrid nanofluids show promise for enhancing thermal performance although there are still challenges and considerations associated with their implementation. This study investigated the effect of adding nanohybrid particles to the base fluid to enhance thermal performance in a concentric tube heat exchanger device. In this study, the heat transport and thermohydraulic behaviour of titanium dioxide–carbon nanotube/water nanofluids in a heat exchanger with and without twisted tape insert were investigated numerically. The works were carried out in the Reynolds number range from 5000 to 10,000 in which the nanoparticle loadings from 0.1% to 0.2%, and a twist ratio of 7 were used. Nusselt number of the observed hybrid nanofluids enhances with increasing Reynolds number although there is an increase in friction factor. It is clearly found that the twisted insert tube of heat exchanger resulted in thermal enhancement compared with the ordinary heat exchanger, and the addition of titanium dioxide–carbon nanotube hybrid nanofluids can enhance Nusselt number. This thermal enhancement contributes to energy savings, which also achieves environmental remediation.

KEYWORDS:

• Heat exchanger
• titanium dioxide
• carbon nanotube
• twisted tape insert
• heat transfer
• friction factor

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Directorate Research, Technology, and Community Service (DRTPM) and the Institute of Research and Community Service of Universitas Sebelas Maret, Surakarta, Indonesia (LPPM UNS) under Fundamental Research scheme with Grant Numbers: 054/E5/PG.02.00.PT/2022 and 469.1/UN27.22/PT.01.03/2022.