Abstract
The study is mainly talking about the interface¡¦s concentration change of the solid(ice)-liquid(water),using an experimental apparatus to measure the gas concentration ahead of the solidification front and building the numerical method to imitate it. When we got the result to match up the production of pores in the interface. With the known the interface¡¦s concentration, we can known the critical radius(Rc) of the instant pores existing, then the change of Gibbs free energy (¡µG) and the change of Helmholtz function(¡µF). To project the situation of pores¡¦ size and quantity from Rc, ¡µG and ¡µF.
From the above experimental pictures and other theories, we can predict gas pores appear during solidification, when the gas concentration in the liquid is higher than the gas solubility at a certain location. From the test, there¡¦s super-cooling contained in liquid(Oxygen dissolute in pure water), when the thin boundary layer of the ice-water interface(an unmixed layer) is getting balanced, the supersaturated ratio is about 16, while the distribution coefficient(k) is about 0.065¡Fthe liquid(Carbon dioxide dissolute in pure water), the supersaturated ratio is about 5.5, while the distribution coefficient(k) is about 0.15.
The rate of solidification is about 4¡Ñ10-6(m/s), the range pores¡¦ radius in the interface is about 0.05mm¡ã0.5mm¡Aand the critical radius¡¦ range of theory is about 0.0046mm¡ã0.1mm. From the above value¡¦s range, the pores¡¦ radius from the picture of this test is reasonable.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0720101-160328 |
| Date | 20 July 2001 |
| Creators | Lee, Kuo-Wei |
| Contributors | none, none, none |
| 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-0720101-160328 |
| Rights | unrestricted, Copyright information available at source archive |
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