Simulation of the entry of an asteroid of ten meters into atmosphere of ten kilometers

2016 Fiscal Year Final Research Report

• Project/Area Number: 26560188
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: Tohoku University
• Principal Investigator: Sun Mingyu 東北大学, 流体科学研究所, 准教授 (00311556)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 衝撃波 / 隕石突入 / 大気層 / 災害 / CFD

Outline of Final Research Achievements

In February 2013, a meteorite dropped in Chelyabinsk, Russia, similar to the Tunguska event in 1908. In this work, we try to calculate the pressure using the technique of computational fluid dynamics (CFD). Our idea is to construct a numerical analysis model that can work more effectively even if the grid is much larger than the meteorite. We treat the small meteorite as a subgrid-scale particle with a finite volume. The Subgrid Closure Model (SCM) was used to handle the movement of subgrid-scale particle while maintaining the entropy condition. We calculate the far-field pressure and evaluate the validity of SCM method. The vertical structure of the atmosphere is also modelled, and it is found that the vertical structure has a significant impact on the over pressure on ground. We succeeded in predicting the overpressure distribution in a region of 50km near the meteorite falling location in one hour using a supercomputer with 128 processors.

Free Research Field

流体工学