高校化学工程学报
高校化學工程學報
고교화학공정학보
Journal of Chemical Engineering of Chinese Universities
2015年
5期
1089-1097
,共9页
唐新宜%朱冬生%戴险峰%曹高
唐新宜%硃鼕生%戴險峰%曹高
당신의%주동생%대험봉%조고
数值模拟%强化传热%凸肋通道%导流装置
數值模擬%彊化傳熱%凸肋通道%導流裝置
수치모의%강화전열%철륵통도%도류장치
numerical simulation%heat transfer enhancement%ribbed channel%deflector device
采用商用CFD软件Fluent对内插四种导流装置(上半圆弧,下半圆弧,圆柱型,斜板型)的凸肋通道传热和流动性能进行了数值模拟。分别研究了导流装置形状,导流装置位置对通道内流场、传热性能与流动阻力的影响。结果表明,与传统凸肋通道相比,内插导流装置的通道平均Nusselt数(Nu)提高了14.8%以上。斜板型导流装置的Nu最大,而圆柱型导流装置的阻力因子 f 最小。从流场及温度场分布可以看出,导流装置的引流作用使部分主流区流体流向凸肋下游的壁面,并与壁面发生了碰撞,减薄了壁面的热边界层,从而提高了传热速率。另外,导流装置向凸肋上游移动时,对传热的影响不明显;导流装置向凸肋下游移动时,流动附着点也随之移动,热边界层被破坏后重新发展,导致传热速率增加。比较导流装置不同位置的综合性能因子(TPF),位置I的效果最优。
採用商用CFD軟件Fluent對內插四種導流裝置(上半圓弧,下半圓弧,圓柱型,斜闆型)的凸肋通道傳熱和流動性能進行瞭數值模擬。分彆研究瞭導流裝置形狀,導流裝置位置對通道內流場、傳熱性能與流動阻力的影響。結果錶明,與傳統凸肋通道相比,內插導流裝置的通道平均Nusselt數(Nu)提高瞭14.8%以上。斜闆型導流裝置的Nu最大,而圓柱型導流裝置的阻力因子 f 最小。從流場及溫度場分佈可以看齣,導流裝置的引流作用使部分主流區流體流嚮凸肋下遊的壁麵,併與壁麵髮生瞭踫撞,減薄瞭壁麵的熱邊界層,從而提高瞭傳熱速率。另外,導流裝置嚮凸肋上遊移動時,對傳熱的影響不明顯;導流裝置嚮凸肋下遊移動時,流動附著點也隨之移動,熱邊界層被破壞後重新髮展,導緻傳熱速率增加。比較導流裝置不同位置的綜閤性能因子(TPF),位置I的效果最優。
채용상용CFD연건Fluent대내삽사충도류장치(상반원호,하반원호,원주형,사판형)적철륵통도전열화류동성능진행료수치모의。분별연구료도류장치형상,도류장치위치대통도내류장、전열성능여류동조력적영향。결과표명,여전통철륵통도상비,내삽도류장치적통도평균Nusselt수(Nu)제고료14.8%이상。사판형도류장치적Nu최대,이원주형도류장치적조력인자 f 최소。종류장급온도장분포가이간출,도류장치적인류작용사부분주류구류체류향철륵하유적벽면,병여벽면발생료팽당,감박료벽면적열변계층,종이제고료전열속솔。령외,도류장치향철륵상유이동시,대전열적영향불명현;도류장치향철륵하유이동시,류동부착점야수지이동,열변계층피파배후중신발전,도치전열속솔증가。비교도류장치불동위치적종합성능인자(TPF),위치I적효과최우。
The influence of 4 types of deflectors (Arc deflector, Inversed arc deflector, Rectangle deflector and Cylinder deflector) on heat transfer and fluid flow in ribbed channel was investigated by using commercial CFD software of Fluent 6.3. The effects of deflector shape and deflector location on fluid flow distribution, heat transfer and flow resistance were also investigated. The numerical results show that compared with conventional ribbed channelNu number for ribbed channel with defectors is increased by more than 14.8%. The case with rectangle deflector provides the highestNu value and the case with cylinder deflector shows the lowestf value. From the analysis of fluid flow and temperature distributions, fluids in the mainstream are induced by deflectors to the bottom wall between ribs. The thermal boundary layers are interrupted by deflecting fluid and fluid impingement on the wall, thus increases the heat transfer rate. On the other hand, the effect of deflector location on heat transfer performance can be ignored when deflectors are located at the upstream region near the rib, while the thermal boundary layers re-develop with the moving of flow attachment point when deflector location moving downstream. Location I shows the best overall thermal performance factor (TPF) by comparing with TPF values at different deflector locations.