Heat transfer characteristics of pulsating flow in a straight channel with rhombic-shaped expanding chamber: A numerical study

ABSTRACT

The combination of passive and active heat transfer recovery techniques in channel flows has significant potential in terms of increasing thermal performance. Therefore, this study focused on the numerical examination of the flow and thermal behavior of pulsating flow in a straight duct containing a rhombus chamber. In the context of the study, iterations were solved using the finite volume method (FVM). The study was carried out for different pulsating amplitudes (A: 0.2, 0.4, 0.6, and 0.8), Strouhal numbers (St: 1, 2, 3, 4), and Reynolds numbers (200 ≤ Re ≤ 800). The surfaces other than the adiabatic lengths at the inlet and outlet of the duct were kept constant at T_w = 360 K. Results were compared with the results of the steady flow case. The effects of pulsating velocity and oscillatory parameters on Nusselt number, pressure drop, and performance factor were discussed. Velocity and temperature images were presented for different Reynolds numbers and pulsating components in the channel. The findings revealed that although the pulsating parameters significantly enhanced the heat transfer at increasing Reynolds numbers, they had a fairly low effect on heat transfer at the same Reynolds number. It was observed that at Re = 800, the Nusselt number formed a peak at St = 3 for all tested pulsating amplitudes. For the parameters of Re = 800, A = 0.6, and St = 2, heat transfer and performance factor in pulsating flow increased by 8.96 and 8.22 times, respectively, compared to steady flow conditions.

KEYWORDS:

• Rhombus chamber
• thermal recovery
• pulsating flow
• friction factor
• performance factor

Disclosure statement

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

Authors’ contributions

Selma Akçay: Conceptualization; Methodology; Formal analysis and investigation; Writing – original draft preparation; Writing – review and editing.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

Selma Akcay

Selma Akcay graduated from Mechanical Engineering Department of the Erciyes University in Turkey in 2000. She received her master’s degree from Aksaray University in Turkey in 2015 and her doctorate from the same University in 2020. She is currently working as an Associate Professor at the Department of Mechanical Engineering of Çankırı Karatekin University in Turkey. She works on heat and mass transfer, oscillatory flow, computational fluid dynamics, nanofluids, and microflow