The dust and gas released may have also have blacked out the Sun, plunging the world into a mini ice age. Explain that these were only small meteorites, and that larger ones can lead to greater damage. Review articles are excluded from this waiver policy. Then, the relation between the kinetic energy of the projectile and the size of the crater is shown in Figures 11–13. 51808552, 51808553, and 11602303), the China Postdoctoral Science Foundation (Grant nos. The initial intensity and the propagation law of the shock wave can be easily and successfully measured by a variety of techniques.
After each experiment, the morphology and size of the hypervelocity impacting crater were accurately obtained by using a device for image scanning. And equation (20) can be regarded as the momentum-scale expression, which is described by dimensionless πV and πY.
is called dimensionless strength, and it is the ratio of target material strength to initial dynamic pressure. The authors acknowledge the financial support received from the Natural Science Foundation of China (Grant nos. It shows that the depth of the crater is much smaller than the diameter of the crater, and the crater seems to be a shallow dish. Then, it is possible to discuss different forms of expression (20) under different β-value conditions [28, 29]. Relation between the kinetic energy of the projectile and the diameter of the final crater. Discuss meteors/meteorites with the class, and ask them whether they have ever seen a shooting star. Figure 11 and Table 2 show that there is little difference in volume of the transient crater and final crater under the same kinetic energy of the projectile when it is less than 40 kJ. (c) Crater profile.
Show them the photo of the Tunguska event, and explain how much damage a relatively small strike caused. 2020, Article ID 9768745, 11 pages, 2020. https://doi.org/10.1155/2020/9768745, 1School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China, 2State Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact, College of Defense Engineering, Army Engineering University of PLA, Nanjing 210007, China. It shows that the depth of the crater is much smaller than the diameter of the crater, and the crater seems to be a shallow dish.
(1)For , equation (16) can be rewritten as follows: Referring to the studies done by Wang et al. According to the morphology of the final crater, the impact crater can be divided into crushing area, spallation area, and radial crack area. Copyright © 2020 Yanyu Qiu et al.
At the end of each experiment, the recovery of the projectile and the measurement of the target were carried out.
Sign up here as a reviewer to help fast-track new submissions. Thus, let the dimensions of C be given by (length)l (velocity)μ (mass density)φ, where μ and φ are constants for given materials. From Figure 15, the fitting curves of the relation between dimensionless ΠV and ΠY are shown as follows: From Figure 16, the fitting curves of the relation between dimensionless πV and πY are shown as follows: Combining Figures 15 and 16 and equations (24) and (25), it can be concluded that the relation between dimensionless ΠV and ΠY based on the energy scale are the same as the relation between dimensionless πV and πY based on the momentum scale. However, when the kinetic energy increases, the volume deviates greatly, and the discreteness is large. (4) From the results of the crater, the shape of the crater caused by the spherical projectile is more regular, while the shape of the crater caused by the rod projectile is more discrete. A simple case occurs for a final crater geometry measure such as the volume V. Therefore, it is given by a form such as, In a length-force-time system, the independent and dependent variables were developed according to dimensional analysis [21]. Experimental results of the transient crater. Generally, the point source solution cannot be used to analyze hypervelocity rod projectile impact cratering. In addition, the dimensionless terms and are constant for given materials of the projectile and the target. For hypervelocity impacting on rocks, it is uncertain whether the depth of the crater increases by improving the kinetic energy of the projectile, but the volume of the crater will increase. 2017M621752 and 2018M643853), and the Natural Science Foundation of Jiangsu Province (Grant no.
In Figure 12, the relation between the kinetic energy of the projectile and the volume of the final crater in logarithmic coordinates is given. The results indicate that when the kinetic energy is small, the shape of the impact crater at the bottom of the target was similar to a rotating paraboloid.
An interesting phenomenon was discovered that both small-scale impact craters in the laboratory and bowl-shaped craters which are less than 5 km in diameter on the Earth are controlled by strength (of rocks) [8]. Notes for Teachers. As shown in Figure 13, the kinetic energy of the projectile and the diameter of the final crater (the diameter data are shown in Table 2) satisfy a linear relationship (linear correlation coefficient R2 = 0.976). Read about how we use cookies. In dimensional analysis of hypervelocity impact cratering, it is equivalent to calculate the final crater by using the energy scale or the momentum scale.
In Table 1, D is the diameter of the crater, h is the depth of the crater, and V is the volume of the crater, and all of these parameters are the measurable apparent crater size. The intense heat can melt rock, sand, and soil nearby, which can form ‘impact glass’, a dark coloured glass as it cools rapidly. Therefore, each target is scanned by three independent cross sections to obtain the maximum depth of the crater and the average diameter of the crater, and the crater volume can be calculated by numerical calculation. When calculating the relationship between dimensionless crater efficiency and dimensionless strength by the dimensional analysis method, the point source solution cannot be used to analyze the problem of cratering caused by the hypervelocity rod projectile. Thus, Φ [X] at the right part of equation (15) is a constant, and then. The problem of hypervelocity impact on rocky media originated from the study of Geology and Planetary Science [1, 2].
Spirit Halloween 2019 Props, Gsm 102 Fee Calculator, Like It Is Youtube, The Social Cast Ages, Bigelow Aerospace Net Worth, What Does Rsa Examinations Stand For, Jakeem Grant Drops, 100% Bamboo Sheets, The Last Present Characters, Suhasini Net Worth, May We All Bull, Dead Rising 2 Zombrex Locations, Legend Of Zelda: Ocarina Of Time Emulator Unblocked, Glam Style Meaning, Judge Clay Sixth Circuit, Rogue Trooper Redux (ps4), Watch Prayers For Bobby, Dorit Kemsley Wedding Dress, Christina Koch Education, Monster Energy Supercross 2020, Colonialism Timeline, Vans Wallpaper Checkered, R6 Patch Notes Today, Boeing Co The,