Rotation‐translation collision model for DSMC with restricted energy exchange

Author(s):  
M. N. Macrossan
Impact ◽  
2019 ◽  
Vol 2019 (10) ◽  
pp. 73-75
Author(s):  
Susumu Hara

Professor Susumu Hara is based at the Department of Aerospace Engineering, Nagoya University in Japan explains that when the Mars rover Opportunity was set to land on that planet in the first weeks of 2004, onlookers held their breath as it dropped from orbit and hurtled toward the red surface. 'Any failure in the calculations or landing systems would mean a harder than expected impact,' he highlights. 'The impacts sustained by a rover such as Opportunity can derail a mission before it even starts, damaging cargo or vital systems required to complete the mission.' Impacts occur during landing but also as the craft enters the atmosphere, when it makes sudden moves, while it is on surface or when debris strikes it. 'Therefore, a system and materials to protect a craft are vital,' outlines Hara. 'Surprisingly, the solutions to this problem are not sophisticated. In fact, most craft still employ devices resembling automobile bumpers, which absorb the energy from an impact by crumpling under the force of said impact.' Unfortunately, these cannot be reused, even during testing phases a new prototype is required after every single test run. Recent missions also employed techniques like airbags or sky cranes. While successful they too have drawbacks. 'Airbags create huge rebounds which can jostle the craft and the contents inside while sky cranes are extremely costly to develop,' Hara says. For this reason, he is dedicated to designing a new highly reliable and cost-effective shock control mechanism.


1998 ◽  
Vol 115 (5) ◽  
pp. 2047-2052 ◽  
Author(s):  
Virpi S. Niemela ◽  
Michael M. Shara ◽  
Debra J. Wallace ◽  
David R. Zurek ◽  
Anthony F. J. Moffat
Keyword(s):  

Author(s):  
Chien-Chang Chou

Navigational safety is an important issue in maritime transportation. The most frequent type of maritime accident in the port and coastal waters is the ship collision. Although some ship collision models have been developed in the past, few have taken account of wind and sea current effects. However, wind and sea current are critical factors in ship maneuvering. Therefore, based on the previous collision model without wind and sea current effects, this study further develops a ship collision model with wind and sea current effects. Finally, a comparison of the results for the proposed collision model in this study and the ship maneuvering simulator is shown to illustrate the effectiveness of the proposed mathematical model in this paper, followed by the conclusions and suggestions given to navigators, port managers, and governmental maritime departments to improve navigational safety in port and coastal waters.


2001 ◽  
Vol 2 (3) ◽  
pp. 329-332
Author(s):  
Dragica ŠIŠŠOVIĆ ◽  
Nikola ŠIŠŠOVIĆ
Keyword(s):  

2021 ◽  
Vol 1859 (1) ◽  
pp. 012050
Author(s):  
Z Kasapeteva ◽  
A Dakova ◽  
V Slavchev ◽  
D Dakova ◽  
L Kovachev ◽  
...  

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