Heat transfer and hydraulic resistance in rod bundles of tubes with counter wire-winding in longitudinal flow

摘要

The paper presents the results of experimental investigation of hydraulic resistance, mixing, and heat transfer of rod bundles consisting of 85 counter wire-wound rods in an axial air flow. The rods were spaced by means of two- and four-wire counter coils. The pitch-to-diameter ratio P/d = 1.23 was used. For the bundle with opposite wire-winding 43 rods were with 4-wire coils and 42 rods were with 2-wire coils. The left direction of wire winding was used for 4-wire coils and the right direction for 2-wire coils. The helical-lead-to-rod-diameter ratio was T/d = 20 for rods with 4-wire coils and T/d = 10 for rods with 2-wire coils. Experiments were performed in an air flow within the range 4.3·10{sup}3 ＜R{sub}e≤7·10{sup}4.