重庆理工大学学报(自然科学版)
重慶理工大學學報(自然科學版)
중경리공대학학보(자연과학판)
JOURNAL OF CHONGQING INSTITUTE OF TECHNOLOGY
2014年
12期
41-46,90
,共7页
王飞%张勃%吉洪湖%刘红梅%赵传亮
王飛%張勃%吉洪湖%劉紅梅%趙傳亮
왕비%장발%길홍호%류홍매%조전량
多斜孔%截面面积%连续变化%强化换热%数值模拟
多斜孔%截麵麵積%連續變化%彊化換熱%數值模擬
다사공%절면면적%련속변화%강화환열%수치모의
inclined multi hole%sectional area%continuously change%enhanced heat transfer%nu-merical simulation
对多斜孔内部流通截面面积进行了对比分析,设计了5种流通面积沿程变化模型,分别为不变(圆柱型)、逐渐减小(渐缩圆台形)、先增大后减小(外凸形)、先减小后增大(内凹形)、逐渐增大(渐扩圆台形)。通过数值模拟研究了其对斜孔内流动与换热特性的影响。结果表明:多斜孔内部流通截面的变化使得其孔内气流压力、流动以及微团流动规律发生显著变化;在截面积由渐缩变为渐扩的过程中,流体微团在出口处转动方向由顺时针转为逆时针;流通面积的扩大使得压力沿程逐渐降低,在多斜孔出口下游形成低压区,出口气膜附壁性增强,气膜冷却效果增强;在多斜孔内,流通面积的扩大使得斜孔内壁背风面压力较大、流速较大、对流换热较强,斜孔内壁迎风面流体脱壁,换热较弱。
對多斜孔內部流通截麵麵積進行瞭對比分析,設計瞭5種流通麵積沿程變化模型,分彆為不變(圓柱型)、逐漸減小(漸縮圓檯形)、先增大後減小(外凸形)、先減小後增大(內凹形)、逐漸增大(漸擴圓檯形)。通過數值模擬研究瞭其對斜孔內流動與換熱特性的影響。結果錶明:多斜孔內部流通截麵的變化使得其孔內氣流壓力、流動以及微糰流動規律髮生顯著變化;在截麵積由漸縮變為漸擴的過程中,流體微糰在齣口處轉動方嚮由順時針轉為逆時針;流通麵積的擴大使得壓力沿程逐漸降低,在多斜孔齣口下遊形成低壓區,齣口氣膜附壁性增彊,氣膜冷卻效果增彊;在多斜孔內,流通麵積的擴大使得斜孔內壁揹風麵壓力較大、流速較大、對流換熱較彊,斜孔內壁迎風麵流體脫壁,換熱較弱。
대다사공내부류통절면면적진행료대비분석,설계료5충류통면적연정변화모형,분별위불변(원주형)、축점감소(점축원태형)、선증대후감소(외철형)、선감소후증대(내요형)、축점증대(점확원태형)。통과수치모의연구료기대사공내류동여환열특성적영향。결과표명:다사공내부류통절면적변화사득기공내기류압력、류동이급미단류동규률발생현저변화;재절면적유점축변위점확적과정중,류체미단재출구처전동방향유순시침전위역시침;류통면적적확대사득압력연정축점강저,재다사공출구하유형성저압구,출구기막부벽성증강,기막냉각효과증강;재다사공내,류통면적적확대사득사공내벽배풍면압력교대、류속교대、대류환열교강,사공내벽영풍면류체탈벽,환열교약。
Five effusion cooled Plates in which the cross-sectional area of the hole continuously changed( circle,taPered cone,convex outside,concave inside and divergent cone)were designed to study the flow and heat transfer characteristics in the hole. The results show that the change of the cross-sectional area in the effusion hole leads to the corresPonding changes of Pressure and the flow characteristic of fluid element in the hole. With the flow area in the hole changes from taPer into di-vergence,the rotation direction of fluid element changes from clockwise to counterclockwise at the ex-it,the exPansion of flow area makes the Pressure lower along,and the Pressure on the lower reaches of the exit is low,which enhances the Coanda effect and film cooling effectiveness. The Pressure on leeward side of the effusion hole is larger,and the cooling effect is better,while on the windward side,the fluid takes off the wall,the Pressure is lower and the cooling effect is worse.