The effects of vortex characteristics on performance of coiled wire turbulators used for heat transfer augmentation

YAKUT K., Sahin B.

APPLIED THERMAL ENGINEERING, cilt.24, sa.16, ss.2427-2438, 2004 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 24 Sayı: 16
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1016/j.applthermaleng.2004.03.008
  • Dergi Adı: APPLIED THERMAL ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.2427-2438
  • Anahtar Kelimeler: heat transfer enhancement, flow-induced vibrations, coiled wire, performance analysis, FLOW-INDUCED VIBRATION, ACOUSTIC-RESONANCE, TUBE BUNDLES, INSERTS, EXCHANGERS
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

The augmentation of the heat transfer by inserting different type turbulators into the channels is the conventional passive enhancement method. The coiled wire is one of the common heat transfer enhancement devices. These turbulators generate almost-periodic vortices into the flow while increasing the heat transfer rate. In this study, the properties of these vortices (i.e. the vortex shedding frequency and amplitudes of the pressure fluctuations of the vortices), flow (vortex)-acoustic coupling and the relation between entropy generation and vortex characteristics were investigated experimentally. Strouhal-Re-N-s,N-a and P-rms-Re-N-s,N-a variations were presented graphically. It was observed that as the pitch increases, the vortex shedding frequencies decrease and the maximum amplitudes of pressure fluctuation of vortices produced by coiled wire turbulators occur with small pitches. In addition, the effects of the turbulators on the heat transfer, friction factor and performance characteristics were investigated. The coiled wires were thermodynamically advantageous (N-s,N-a < 1) up to 13,000 Reynolds number. (C) 2004 Elsevier Ltd. All rights reserved.