This study investigates the effect of fin length on solidification characteristics of deionized water filled in a stainless steel spherical capsule immersed in a constant temperature bath. Alongside, Box-Benkehn experimental design is employed to develop mathematical models for predicting solidification duration using response surface regression. Experiments are carried out at three different bath temperatures (−6°C − 9°C and −12°C). Four radial fins of 3 mm diameter made of copper are fixed on the inner surface of the spherical capsule. Three fin-lengths of 7.5 mm, 13.5 mm, and 19.5 mm are chosen which corresponds to the annulus volume margins of 50%, 75%, and 90% respectively measured from the inner surface of the capsule. Results revealed that the fin length has no significant effect on the duration of solidification. The individual as well as interactive effects of frozen mass fraction and bath temperature were found to be statistically significant. The models developed were found to be statistically significant at a 99% confidence level and the confirmatory experiments validated that the developed models were able to predict the solidification time with reasonable accuracy. It was found that there is an improvement in solidification duration in the range between 17% and 21% using the combinations predicted by the desirability approach when compared to a capsule fitted with no fin under similar conditions. The spherical capsule fitted with a fin of length 16.5 mm shows a reduction of 21% in solidification duration to achieve 96% of frozen mass at a bath temperature of −12°C.

本研究研究了翅片长度对浸没在恒温浴中的不锈钢球形胶囊中填充的去离子水的凝固特性的影响。同时，采用Box-Benkehn实验设计来开发数学模型，以使用响应面回归来预测凝固持续时间。在三种不同的浴温（-6°C-9°C和-12°C）下进行实验。球形胶囊的内表面固定有四个直径为3 mm的铜制径向鳍片。选择7.5毫米，13.5毫米和19.5毫米的三个翅片长度，分别对应于从胶囊内表面测得的环空体积裕度为50％，75％和90％。结果表明，翅片长度对凝固时间没有显着影响。发现冷冻质量分数和浴温的个体以及相互作用的影响在统计学上是显着的。发现所开发的模型在99％的置信水平上具有统计学意义，并且验证性实验验证了所开发的模型能够以合理的准确性预测凝固时间。已经发现，与在类似条件下没有翅片的胶囊相比，使用通过期望方法预测的组合，固化持续时间提高了17％至21％。装有长度为16.5 mm的翅片的球形胶囊在-12°C的浴温下，凝固持续时间减少了21％，可实现96％的冷冻质量。