Analysis of thermal-hydraulic comprehensive performance of composite corrugated tubes composed of simple droplet-shaped corrugations

Abstract

Corrugation parameter design seeks to maximize the thermal-hydraulic comprehensive performance (THCP) of corrugated tubes as much as possible. Among them, composite corrugations composed of simple corrugations are proposed to strengthen the THCP of corrugated pipes. However, the rule and mechanism regarding the impact of composite corrugations on the THCP of corrugated tubes, particularly when those composite corrugations are composed of simple asymmetric corrugations, are not well understood. Therefore, in this work, the effect of composite corrugations consisting of two simple droplet-shaped corrugations on THCP is assessed numerically, where the first composite corrugation is concave-convex (CTCC1) and the second composite corrugation is concave-concave (CTCC2). In addition, the effect of traditional corrugation (CTSC) on THCP is also examined to further highlight the advantages of composite corrugation in enhancing the THCP of corrugated tubes. The results of the study indicated a 49 %, 55 %, and 61 % increase in THCP at a Reynolds number (Re) of 5000 for CTSC, CTCC1, and CTCC2, respectively, compared to a smooth tube, indicating that the combination of composite corrugations in CTCC2 is superior to that in CTCC1. In addition, a smaller corrugation width on the upstream side of CTCC2 is more conducive to enhancing THCP. Furthermore, it should be ensured that the corrugation depth on the upstream side of CTCC2 is not greater than the depth on the downstream side to achieve better THCP. The work confirms the advantages of composite corrugations over traditional corrugations in enhancing THCP and guides the selection of composite corrugation combination forms and the design of composite corrugation width and depth distribution.