About one method of ultrasonic well drilling for soil sampling on celestial bodies

The article discusses technical and theoretical issues in the development of an ultrasonic drill for drilling soil on celestial bodies. The specific use of the drill requires low energy consumption, an efficient operating cycle and a wide temperature range during operation. One of the promising areas of development is devices that have vibration decoupling from the ground due to the transformation of ultrasonic vibrations into repeated shocks of sound frequency through a specially introduced “free” body between the ultrasonic and impact parts of the device. This allows you to maintain the functionality of the device and carry out drilling regardless of the state of the impact bit, including even its temporary jamming. The main technical solutions of both domestic and foreign authors are considered, an analysis is made and design schemes, operating conditions, capabilities and limitations are evaluated. A number of theoretical works were also analyzed and it was found that the materials presented in them do not contain detailed mathematical models necessary for simulation modeling at the stage of design and optimization of the structure. The theoretical part of the article considers a lumped mathematical model obtained on the basis of equivalent parameters obtained from a distributed description of the drill design elements in numerical calculation systems. The equations of mathematical physics, classical mechanics, elements of impact theory and similarity theory were used. A parametric study was carried out and, in particular, the dependences of the oscillation frequency of a free body on the size of the impact gap, body mass and the amplitude of oscillations of the concentrator were obtained. The considered model can be used for simulation modeling when developing a drill design.