Mixed convection heat transfer from a triangular cylinder subjected to upward cross flow


ALTAÇ Z., SERT Z., MAHİR N., TİMURALP Ç.

INTERNATIONAL JOURNAL OF THERMAL SCIENCES, cilt.137, ss.75-85, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 137
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1016/j.ijthermalsci.2018.11.010
  • Dergi Adı: INTERNATIONAL JOURNAL OF THERMAL SCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.75-85
  • Anahtar Kelimeler: Triangular cylinder, Assisting flow, Flow characteristics, Mixed convection, Nusselt correlations, FORCED-CONVECTION, THERMAL BUOYANCY, PLANE CHANNEL
  • Eskişehir Osmangazi Üniversitesi Adresli: Evet

Özet

Unsteady laminar mixed (forced and free) convection heat transfer and fluid flow over long horizontal equilateral triangular cylinder subjected to upward cross flow are investigated numerically. The computation model is a two-dimensional unconfined rectangular domain with an aspect ratio of 1.4. A second order upwind scheme was used for differencing of the convection terms, and SIMPLE algorithm was adopted. The working fluids are air (Pr = 0.7) and water (Pr = 7). The equilateral isothermal triangular cylinder is placed in a uniform stream. The effect of buoyancy is incorporated into the Navier-Stokes (NS) equations using the Boussinesq approximation. This study is a case of "assisting flow" where the buoyancy-induced flow and fluid motions have the same upward direction. The basic dimensionless simulation variables, Reynolds and Richardson numbers, are varied in the range 10 <= Re <= 200 and 0 <= Ri <= 10. The flow characteristics such as the mean drag, mean rms lift coefficients and the Strouhal number are computed for each simulation. The flow patterns and isotherms are generated to interpret and understand the underlying physical mechanism. The cylinder surface mean Nusselt number was computed for mixed as well as for forced and free convection conditions. The computational data were used to develop the several Nusselt number correlations for forced, free and mixed convection flow.