내 원통이 회전하는 수평 두 원통간의 대류 열전달

Abstract

내 원통이 회전하는 수평 두 원통간의 천이영역의 대류 열전달에 대하여 실험적으로 연구하였다. 회전 Reynolds수를 10~2000, 내 원통과 외 원통의 온도차이를 9℃~40℃, 두 원통사이의 간극(R?-R?)을 0.4~7mm범위 안에서 변화시켰고 test cylinder주위의 유체로는 공기를 사용하였다. 실험 Data를 고찰한 결과 회전 Reynolds수가 약 160(혹은 modified Taylor수가 약 1700)일때 층류영역에서 부터 난류 영역으로의 천이가 이루어졌고 (Ta)?수가 5000보다 큰 영역에서 열전달은 간극비변화에 거의 무관하고 내원통의 회전속도에만 관계되었다.

A Study on Heat Transfer of Transition region Between Two Horizontal Concentric Cylinders with an Inner Rotating Cylinder was evaluated experimentally for a range of Reynolds number from 10 to 2000, temperature difference between Cylinders from 9℃ to 40℃, radius difference of Cylinders from 0.4mm to 7mm. Air was used as fluid between cylinders. From the observed data transition from laminar region to turbulent was observed at the rotating Reynolds number about 160(or at the modified Taylor number about 1700), and Heat Transfer was not relevant to Clearance ratio but relevant to rotating speed at the modified Taylor number above 5000.

A Study on Heat Transfer of Transition region Between Two Horizontal Concentric Cylinders with an Inner Rotating Cylinder was evaluated experimentally for a range of Reynolds number from 10 to 2000, temperature difference between Cylinders from 9℃ to 40℃, radius difference of Cylinders from 0.4mm to 7mm. Air was used as fluid between cylinders. From the observed data transition from laminar region to turbulent was observed at the rotating Reynolds number about 160(or at the modified Taylor number about 1700), and Heat Transfer was not relevant to Clearance ratio but relevant to rotating speed at the modified Taylor number above 5000.