Effect of corrugated channel phase shifts on flow structures and heat transfer rate


TOKGÖZ N., Tunay T., ŞAHİN B.

EXPERIMENTAL THERMAL AND FLUID SCIENCE, cilt.99, ss.374-391, 2018 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 99
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1016/j.expthermflusci.2018.08.011
  • Dergi Adı: EXPERIMENTAL THERMAL AND FLUID SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.374-391
  • Anahtar Kelimeler: Corrugated channels, Heat transfer, PIV, Turbulent flow, SOLAR AIR HEATER, TRANSFER ENHANCEMENT, TURBULENT-FLOW, FLUID-FLOW, PERFORMANCE, CONVECTION, ROUGHNESS, EXCHANGER, TUBES, SHAPE
  • Çukurova Üniversitesi Adresli: Evet

Özet

The study of quantitative visualization of flow hydrodynamics, turbulent flow characteristics and time-dependent development and disappearance of vortices in cavities of corrugated channel regarding enhancements of heat transfer is limited in the literature. For this reason, the aim of the work is to search the effects of two different phase shifts, phi (i.e. 90 degrees, 0 degrees) of corrugated channels on flow hydrodynamics and the rate of heat transfer for Reynolds numbers varying from 3 x 10(3) to 6 x 10(3). The technique of particle image velocimetry (PIV) which has the capability of observing turbulent unsteady flows and provide instantaneous velocity vectors covering defined flow fields were employed. An effective fluid mixture occurs between the core and the separated flow regions due to the occurrence of a rapid vortex shedding downstream of the entrance of cavities. Along the lower and upper sides of hollow spaces, these shedding vortices spin either counterclockwise or clockwise to stimulate entrainment. In addition, the effects of turbulent flow hydrodynamics on convective heat transfer were also investigated numerically. Numerical results of flow hydrodynamic were found to be consistent with the experimental results. Heat transfer augmentation was reported as a conclusion of different parameters including different phase shifts, phi, aspect ratios, s/H and Reynolds numbers, Re.