Intensification of Thermal Performance of a Heat Exchanger Tube with Knitted Wire Coil Turbulators Installed

dc.contributor.authorWongcharee, K.
dc.contributor.authorShoon Wai, T.
dc.contributor.authorMaruyama, N.
dc.contributor.authorHirota, M.
dc.contributor.authorChuwattanakul, V.
dc.contributor.authorPromthaisong, P.
dc.contributor.authorEiamsa-ard, S.
dc.date.accessioned2026-08-06T10:52:47Z
dc.date.available2026-08-06T10:52:47Z
dc.date.issued2025-12-01
dc.description.abstractThis study reports on heat transfer augmentation by knitted wire coil turbulators in a fully developed turbulent regime. Four knitted wire coil turbulators with different wire loop number densities (N = 6, 8, 10, and 12 loops per pitch, with 1.0 pitch = 6.8 mm) were tested. Each was made by winding a 0.7 mm copper wire around a 1.0 mm core rod. Experiments were conducted under a constant 600 W/m<sup>2</sup> wall heat flux. The flow behaviors observed through a dye injection technique revealed that the wire coil induced secondary flows and developed shear layers, contributing to enhanced heat transfer. Heat transfer improved with increasing wire loop number density. Application of knitted wire coil turbulators increased the Nusselt number (Nu) by 86, 95.4, 103.2, and 109.3% for N = 6, 8, 10, and 12, respectively. This corresponded to increased friction factors (f) by 1.77, 1.97, 2.15, and 2.31 times, respectively. The tube with coils having N = 12 yielded the highest thermal performance index (TPI), 1.4, at a Reynolds number of 5000. The empirical correlations for Nu, f, and TPI showed deviations within ±2.1, ±0.68, and ±2.28%, respectively.
dc.identifier.citationEng, 6(12), 2025
dc.identifier.doi10.3390/eng6120337
dc.identifier.issn26734117
dc.identifier.other2-s2.0-105026128103
dc.identifier.urihttps://dspace.kmitl.ac.th/handle/123456789/17398
dc.sourceEng
dc.subjectcoiled wire
dc.subjectheat transfer enhancement
dc.subjectknitted wire coil
dc.subjectmesh
dc.subjectthermal performance index (TPI)
dc.subjectturbulence
dc.titleIntensification of Thermal Performance of a Heat Exchanger Tube with Knitted Wire Coil Turbulators Installed
dc.typeArticle

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