3748

3542

كارشناسي ارشد

تبديل انرژي

اصفهان :دانشگاه صنعتي اصفهان ،دانشكده مكانيك

1386

يازده ، 122 ،[II]ص. : مصور،جدول،نمودار

ص.ع. به فارسي و انگليسي

علي اكبر عالم رجبي

04/09/86

احمد صابونچي،محمود اشرفي زاده

مهندسي مكانيك

ID3542

به فارسي و انگليسي : قابل رؤيت در نسخه ديجيتال

123AbstractIn recent years increasing the heat transfer coefficient has been the main problem of theresearchers and increasing the internal heat transfer coefficient has a special importance For receiving to this goal different methods were used One of these methods forincreasing the internal heat transfer is using different shapes of disks in tube Of courseusing these disks in tube will cause to increase the pressure loss In this investigation have been tried to study the effect of wooden disks that were placedin a tube with fixed wall temperature in regular space on heat transfer and pressure loss inthe range of Reynolds number between 4000 to 40000 Also with defining the PerformanceEvaluation Criterion P E C as a relation between heat transfer and pressure losseconomic use of disks have been studied For receiving to this goal two groups of disksincluding ring shaped and not hollow disks have been considered According to the earnedresults ring shaped disks have better P E C than not hollow disks In this investigationangle of disks relative to the flow direction have been studied According to the earnedresults disks that have placed at angle 45 relative to flow direction have a better P E C than vertical disks In all disks in the mentioned range of Reynolds number increasing theReynolds number will cause to decreasing P E C and the maximum value of P E C happens near Re 4000 The maximum values of P E C are 1 85 in elliptical hole disks and1 91 in rectangular hole disks

علي اكبر عالم رجبي

احمد صابونچي،محمود اشرفي زاده