Vandana Kumari Jha
Department of Chemical Engineering, Indian Institute of Technology (ISM)
Dhanbad, India, 826004
Soubhik Kumar Bhaumik
Department of Chemical Engineering, Indian Institute of Technology (ISM)
Dhanbad, India, 826004
A novel configuration of cross-flow helical tube (CFHT)
heat exchanger with elliptical tube cross-section is studied and its cooling characteristics are examined and compared with the CFHT heat exchanger with circular tube cross-section
numerically, having equal cross-sectional area. Based on the
cooling potential, which is an outcome of the flow
characteristics and rate of heat extraction, elliptical tube crosssection is found to be more effective. An array of (3 × 3) tubes in an inline arrangement is considered and observed that increase in the rate of heat extraction per unit volume of heat exchanger is as high as 1.12-1.63 times for CFHT heat exchanger with an elliptical cross-section. The effectiveness of elliptical-shaped tube cross-section for three different helix angles ranging from 35° ≤ φ ≤ 72° is explored under laminar air-flow conditions (150 ≤ Re ≤ 4500 ). Air side pressure drop is also examined and is found to vary from 1.31-1.83 times
higher in case of circular tube cross-section. Improved heat
transfer performance and reduced pressure drop in case of
elliptical tube cross-section highlights its higher potential over circular tube cross-section in cross-flow arrangement.