Abstract
There are three focal points in this experimental study¡G(1)Change Reynolds number(Re) and measure the heat transfer coefficients on upper¡Bback¡Bside and front surfaces of a chip for standard height(20mm)¡F(2)Influences of the surface heat transfer coefficients when change the heights of a chip to 10mm and 30mm , then compare with the results of a chip with standard height¡F(3)Compare the heat transfer effects of a chip on different positions of the testing region. The range of Re is 2000~10000 in this experiment and the chip sets are installed on the testing board with a 3x4 array.
According to similarity principles to setup whole experimental models¡Fassume this experimental system is a semi-infinite region and its heat transfer model is one dimension¡Fuse the transient heat transfer method with thermochromic liquid crystal as the surface thermometer , then we assemble micro video cameras in the experimental system to obtain the color changing images on chip surfaces. The software , LCIA (Liquid Crystal Image Analysis) , is used to analysis the changed color and the temporal history of the surface temperatures to determine the local heat transfer coefficients on chip surfaces.
The results show¡G(1)The heat transfer coefficients on chip surfaces are increased with Re and effects of vortex¡F(2)Upper surface of the chip has the largest average heat transfer coefficient(h) , front surface and side surface have almost the same at lower Re , but at higher Re , of front surface is larger than side surface¡Fback surface has the lowest ¡F(3)When change the height of the first chip to 10mm , it has the best heat transfer effects at Re=2175 and 3257¡Fthere is almost the same effects at Re=4423 with different heights(10mm , 20mm and 30mm) and from Re=5535 to 9973 , this chip has the best heat transfer effects at 30mm. Then change the heights of the second and third chips , there are the best heat transfer effects at 30mm and the lowest at 10mm¡F(4)When fix heights of the chips at 10mm and 20mm , there are more better heat transfer effects as chips more close to the entrance of the testing channel , but once the heights of chips are 30mm , the positions of chips on the testing region are not very important influences to heat transfer effects.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0629101-094707 |
| Date | 29 June 2001 |
| Creators | Wang, Ying-Jr |
| Contributors | Ru Yang, Pey-Shey Wu, Chien-Yu Yang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0629101-094707 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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