EXPERIMENTAL AND NUMERICAL ANALYSIS OF FLOW AND HEAT TRANSFER IN CLOSED THERMOSYPHON LOOP

Abstract

In this study, closed loop rectangular thermosyphon was studied using an analytical, numerical and experimental techniques. One-dimensional analytical and two-dimensional numerical models were solved using uniform surface temperature boundary condition in the vertical heating and cooling sections of the thermosyphon loop for fully developed laminar flow in circular tube. It was shown that the one-dimensional model was inappropriate for estimating the heat transfer and the flow characteristics of the loop at the uniform surface temperature. However, two-dimensional numerical model provides results which are in good agreement with experiments for Reynolds numbers up to 310. At higher values of Reynolds numbers, due to turbulent distortion of the flow, a discrepancy in the calculated and measured velocity as well as temperature values was noted. In calculating the heat transfer rate, however, the two-dimensional model provides meaningful results.

Keywords

• Termosifon, Kapalı döngü, Doğal taşınım döngüsü, SIMPLEX algoritması