This paper describes parallel simulation techniques for the discrete element method （DEM） on multi-core processors. Recently, multi-core CPU and GPU processors have attracted much attention in accelerating computer ...This paper describes parallel simulation techniques for the discrete element method （DEM） on multi-core processors. Recently, multi-core CPU and GPU processors have attracted much attention in accelerating computer simulations in various fields. We propose a new algorithm for multi-thread parallel computation of DEM, which makes effective use of the available memory and accelerates the computation. This study shows that memory usage is drastically reduced by using this algorithm. To show the practical use of DEM in industry, a large-scale powder system is simulated with a complicated drive unit. We compared the performance of the simulation between the latest GPU and CPU processors with optimized programs for each processor. The results show that the difference in performance is not substantial when using either GPUs or CPUs with a multi-thread parallel algorithm. In addition, DEM algorithm is shown to have high scalabilitv in a multi-thread parallel computation on a CPU.展开更多
4 Summary and conclusion The JOULE sounding rocket 1 experiment was carried out at Poker Flat Research Range in Alaska around 1200 UT on March 27th,2003 with two instrumented rockets and one chemical tracer rocket.Fro...4 Summary and conclusion The JOULE sounding rocket 1 experiment was carried out at Poker Flat Research Range in Alaska around 1200 UT on March 27th,2003 with two instrumented rockets and one chemical tracer rocket.From the released TMA trails,neutral wind measurements from approximately 85 to 160 km altitude showed a vertically propagating wave and a jet structure around 120 km altitude.Large shears appeared at the bottom side of the jet with Richardson numbers close to or smaller than the critical value of 0.25,which implies the possible existence of Kelvin-Helmholtz instabilities caused by the vertical shear in the fast flows.展开更多
文摘This paper describes parallel simulation techniques for the discrete element method （DEM） on multi-core processors. Recently, multi-core CPU and GPU processors have attracted much attention in accelerating computer simulations in various fields. We propose a new algorithm for multi-thread parallel computation of DEM, which makes effective use of the available memory and accelerates the computation. This study shows that memory usage is drastically reduced by using this algorithm. To show the practical use of DEM in industry, a large-scale powder system is simulated with a complicated drive unit. We compared the performance of the simulation between the latest GPU and CPU processors with optimized programs for each processor. The results show that the difference in performance is not substantial when using either GPUs or CPUs with a multi-thread parallel algorithm. In addition, DEM algorithm is shown to have high scalabilitv in a multi-thread parallel computation on a CPU.
基金supported by the National Science Foundation(NSF)(Grant No.ATM0955629)the National Aeronautics and Space Administration(NASA)(Grant Nos.NNX13AD64G and NNX14AD46G)Air Force Office of Scientific Research(AFOSR)(Grant Nos.FA9550-16-1-0059 and MURI FA9559-16-1-0364)
文摘4 Summary and conclusion The JOULE sounding rocket 1 experiment was carried out at Poker Flat Research Range in Alaska around 1200 UT on March 27th,2003 with two instrumented rockets and one chemical tracer rocket.From the released TMA trails,neutral wind measurements from approximately 85 to 160 km altitude showed a vertically propagating wave and a jet structure around 120 km altitude.Large shears appeared at the bottom side of the jet with Richardson numbers close to or smaller than the critical value of 0.25,which implies the possible existence of Kelvin-Helmholtz instabilities caused by the vertical shear in the fast flows.
