非对称型外凸式波节管内的传热和流动特性

Heat transfer and flow characteristics in asymmetrical outward convex corrugated tubes

针对一种新型的非对称外凸式波节管(ACT)换热元件,基于三维RST模型对其进行了数值模拟研究。通过与传统的对称型外凸式波节管(SCT)分析比较,考察了两者流动及传热特性的区别。为了验证雷诺应力模型(RST)在研究波节管结构时的可靠性,比较了现有波纹壁面中直接数值模拟(DNS)与RST模型在同一条件下的计算结果。通过对比发现,RST模型得出的包括速度场、压力系数等计算结果与DNS所得出的结果基本吻合。随后对外凸型的流动及传热机理进行了深入探讨。结果表明,与传统的SCT相比,ACT提高综合传热性能最多能够提高32.3%。

A new style asymmetrical outward convex corrugated tube （ACT） was studied with numerical simulation based on the three-dimensional Reynolds stress transport （RST） model. The ACT is compared with the traditional symmetrical corrugated tube （SCT） to investigate their difference in flow and heat transfer characteristics. The calculation results from existing direct numerical simulation （DNS） are compared to those from RST model under the same condition to check the reliability of RST model for the corrugation tube. The calculation results for velocity and pressure coefficient at different profiles from RST and DNS are in good agreement. The fluid flow and heat transfer mechanism are investigated in the outward convex corrugated tube. Compared to SCT, ACT presents up to 32.3% higher overall heat transfer.