新型扭带在层流中强化传热性能的数值模拟研究  

Numerical studies on heat transfer enhancement of a new type twisted tape in laminar flow

作　　者：满长忠[1] 胡敬伟 郁双鑫 孙培岩[1] 唐运榜[1] MAN Chang-zhong;HU Jing-wei;YU Shuang-xin;SUN Pei-yan;TANG Yun-bang(School of Energy and Power Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学能源与动力学院,辽宁大连116024

出　　处：《热科学与技术》2019年第1期42-49,共8页Journal of Thermal Science and Technology

摘　　要：提出一种新型的正反两个方向交替扭转的扭带模型,并基于ANSYS FLUENT软件在层流状态下(Re=400～18 00)对换热管中插入新型扭带的换热特性、流体阻力特性和综合性能指标进行数值模拟研究。对y=3.0,4.5,6.0三种扭率下的无缺口正反扭转扭带与传统单一方向扭带进行对比研究,并对扭率y=3.0的无缺口正反扭转扭带和带有三角、半圆及方形缺口的正反扭转扭带进行了对比计算。研究结果表明:插入不同扭率的扭带,换热管的努赛尔数Nu、摩擦系数f与综合性能PEC值均随着扭率的减小而增大;相同扭率下无缺口的正反扭转扭带在强化换热效果和综合性能表现上要优于传统扭带;扭率为3.0时,无缺口的正反扭转扭带比带三种缺口的正反扭转扭带换热效果好,而缺口的存在可以大幅度地降低插入扭带产生的摩擦阻力,且缺口的面积越大,摩擦和换热效果降低越多。A new tape twisted tape is presented which alternatelyrotatesin left and right directions.Numerical investigations based on ANSYS FLUENT are carried out on characteristics of heat transfer,fluid flow and performance evaluation criteria(PEC)in heat exchanger with this new twisted tape for laminar flow(Re=400-1 800).The comparison of typical twisted(TT)and Left and Right twisted tape(LRTT)without cut with twisted ratio 3.0,4.5,6.0 has been studied together with the comparison of LRTT without cuts and LRTT with triangle,semicircle and square cuts with twisted ratio 3.0.The results show that the Nusselt numbers,friction factors and PEC are increased with decreasing of twist ratio.The heat transfer enhancement and PEC of LRTT without cuts are better than that of TT with same twist ratio.Heat transfer effect of LRTT without cutsisbetter than that of LRTT with three type of cuts,while the existence of the cuts can extremely reduce friction resistance for LRTT.And the friction resistance and heat transfer are reduced with increasing area of cuts.

关 键 词：数值模拟 层流 正反转扭带 扭率 强化传热 

分 类 号：TK124[动力工程及工程热物理—工程热物理]