Numerical investigation of the impact of various design parameters of finned-pipes on mixed convection | ||
| Al-Qadisiyah Journal for Engineering Sciences | ||
| Volume 15, Issue 1, March 2022, Pages 55-66 PDF (885.24 K) | ||
| DOI: 10.30772/qjes.v15i1.814 | ||
| Authors | ||
| Rassol H. Rasheed* ; Majid H. Majeed; Ahmed Q. Mohammed | ||
| The Technical Engineering College, Middle Technical University, Baghdad, Iraq | ||
| Abstract | ||
| The mixed convection investigation of various design parameters utilizing finned pipes in the cylindrical enclosure has been investigated computationally. Various geometries of fins are used (circular and longitudinal). The effect of fins number (12-16), aspect ratio (1.83-2.7), radius ratio (2-3) and fins geometry have been introduced within the present study. The observations show that when Richardson number=0.5 and 5.5, the heat transfer decreases by 12.22% and 7.777%.,. Values of the Nusselt number rise as the number of fins increases. While, when the Rayleigh number is high, no noticeable variations in the numbers of fins (12 and 14). The purpose of using fins is to increase the surface area of heat transmission. The highest heat transfer improvement is shown to be 4.2%, when log (Rayleigh)=7.342 and 16 fins are utilized. The radius ratio does not affect Nusselt number throughout the whole Richardson and Rayleigh in both hot and cold locales. The turbulence sub-layer does not affect the free stream behaviour for different Richardson number. In the case of high Richardson number, the geometry does not influence the Nu. Longitudinal fins do not have dead zones, unlike circular fins, which have channelling generated by geometrical arrangement. To reach thermal equilibrium in a cold environment, the Nu in rectangular fins was reduced by 18% as compared to circular fins with a low Richardson number. Flow development would increase the impact of channelling. The heat transfer improvement decreases as the number of fins increases, as illustrated in temperature and velocity profiles for various values. | ||
| Keywords | ||
| Mixed convection; CFD; Enclosure; Ri; Finned pipes | ||
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