Numerical Simulation Study of a Swirling Drill Bit Used for Ice Core Drilling
Numerical Simulation Study of a Swirling Drill Bit Used for Ice Core Drilling
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DOI：
10.3390/jmse10020296
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发表时间：
2022-02
影响因子：
2.9
通讯作者：
Mengke Wang;W. He;Minqi Wang;Jin Cao;P. Cao
中科院分区：
文献类型：
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作者：
Mengke Wang;W. He;Minqi Wang;Jin Cao;P. Cao
由于机械钻速高且对环境无污染，空气反循环钻探被认为是一种有前途的冰钻方法。空气逆循环是由钻头内的喷射器和冲洗喷嘴组合而成。本文利用CFD软件模拟了旋流器结构对旋流钻头空气反循环效果的影响，并建立了试验台对空气反循环进行测试。结果表明，对于不带冲洗喷嘴的钻头，螺旋角越小，夹带率越大，而面积比越小，夹带率越大。相比之下，对于采用冲洗喷嘴设计的钻头，螺旋角越大，夹带比越大，面积比越大，夹带比也越大。此外，冰芯的存在大大降低了空气逆循环的效果。当冰芯高度超过旋流器出口高度时，反循环效果略有改善。
Due to its high mechanical penetration rate and lack of pollution of the environment, air reverse circulation drilling is considered to be a promising method for ice drilling. The air reverse circulation is caused by the combination of the ejector and the flushing nozzles in the drill bit. In this paper, CFD software was used to simulate the influence of the structure of the swirler on the effect of air reverse circulation in the swirling drill bit, and a testing stand was established for the testing of air reverse circulation. The results show that for drill bits without flushing nozzles, the smaller the helical angle is, the larger the entrainment ratio will be, meanwhile the smaller the area ratio is, the larger the entrainment ratio will be. In contrast, for drill bits designed with flushing nozzles, the larger the helical angle is, the larger the entrainment ratio will be, and the larger the area ratio is, the larger the entrainment ratio will be. In addition, the presence of the ice core sharply reduces the effect of air reverse circulation. When the ice core’s height exceeds that of the outlet of the swirler, the reverse circulation effect is slightly improved.