Topic：Ultrasonic, vibrating, and oscillating structures for ground exploration 

Lecturer：Prof. Patrick Harkness（University of Glasgow, UK）

Time：November.19, 2021, 20:00-21:00（GMT+8）

Location：Tencent meeting ID: 687670724 

Organizer：College of Aerospace Engineering

Abstract：

 The exploration of remote areas (such as the polar regions of the earth, or the surfaces of other planets) require relatively small systems that must penetrate the terrain with small amounts of power and at low levels of force. Different terrains present different problems. Granular materials such as sand behave in surprising ways, and ultrasonic vibration can be used to disrupt the mechanisms by which they resist penetration forces. Ultrasonic vibration can also be superimposed on drill tools, applied to rock, with a positive outcome, but when this technique is applied to ice it may cause melting and then cavitation, which can damage the tool. And, at depth, it becomes more difficult to sustain ultrasonic vibration over a long waveguide, and so the hammer mechanism may be separated from the drill, using either the ultrasonic percussion or hammer percussion mechanism. These first items are only the problems of cutting the terrain. The cuttings, both debris and samples, must be lifted out of the hole if progress is to continue. Ultrasonic techniques are being investigated for this application also, to see if the power and force requirements associated with augering – which is perhaps more difficult than cutting – can be reduced as well. Finally, there are the problems of learning how to explore in space, which is very expensive and does not tolerate mistakes. We will discuss how exploration in analogue environments (such as Antarctica) can be used to gain know-how, and produce scientific results which justify the training expeditions in their own right (especially in the context of environmental research).

Biography：

 Patrick Harkness是英国格拉斯哥大学医学与工业超声中心教授，2003年获得贝尔法斯特女王大学航空工程硕士学位，2007年获得克兰菲尔德大学博士学位。Harkness教授对行星表面样本采集很感兴趣，致力于创建具有自组装钻柱的机器人设备，实现采集和容器化岩石样本，并在火星模拟站点展示了自主钻井性能。在欧洲航天局和欧洲科学研究委员会资助下，Harkness教授开展了空间和极地科学钻探项目，未来几年将在英国、格陵兰岛和南极洲进行测试活动。