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Primeur weekly 2015-03-30

Exascale supercomputing

PRACEdays15 to include EESI2 Final Conference, Women in HPC, and Enabling Exascale in Europe ...

The Cloud

HP delivers first fully-configured and integrated OpenStack and Cloud Foundry-based private Cloud ...

Desktop Grids

BOINC 7.4.42 released to the public ...

EuroFlash

Altair Engineering announces keynote speakers from Airbus, Jaguar Land Rover and Bloodhound SSC to present at the 9th UK Altair Technology Conference ...

UK Atomic Weapons Establishment awards SGI contract to support research with new SGI ICE XA systems ...

Cray to deliver five-petaflop supercomputer and high-performance storage system to Petroleum Geo-Services ...

Theory of the Strong Interaction verified - Supercomputer calculates mass difference between neutron and proton ...

Lenovo opens first global High Performance Computing innovation centre in Germany ...

A rehearsal space with musicians 2,700 kilometers apart from each other ...

A first glimpse inside a macroscopic quantum state ...

USFlash

Automotive, aerospace and defense take centre stage at the 2015 Americas Altair Technology Conference ...

Big Data allows computer engineers to find genetic clues in humans ...

SGI delivers cutting-edge supercomputer to the National Institute for Materials Science ...

Supercomputers give universities a competitive edge, researchers find ...

Engineers develop new methods to speed up simulations in computational grand challenge ...

Micron and Intel unveil new 3D NAND flash memory ...

India's National Supercomputing Mission (NSM): Building capacity and capability to be jointly implemented by the Department of Science and Technology and Department of Electronics and Information Technology ...

U.S. Army improves systems testing to deliver more capability to fight ...

Quantum compute this - WSU mathematicians build code to take on toughest of cyber attacks ...

IBM invests in Modernizing Medicine to accelerate adoption of Watson technologies in health care ...

Quantum correlation can imply causation ...

From programmable backbones to advanced 'apps': An end-to-end vision of the future Internet ...

Building shape inspires new material discovery ...

UW scientists build a nanolaser using a single atomic sheet ...

OpenPOWER Foundation technology leaders unveil hardware solutions to deliver new server alternatives ...

Engineers develop new methods to speed up simulations in computational grand challenge


Thomas Bewley/Jacobs School of Engineering/UC San Diego
26 Mar 2015 San Diego - Engineers at the University of California, San Diego, have developed a new family of methods to significantly increase the speed of time-resolved numerical simulations in computational grand challenge problems. Such problems often arise from the high-resolution approximation of the partial differential equations governing complex flows of fluids or plasmas. The breakthrough could be applied to simulations that include millions or billions of variables, including turbulence simulations.

Modern computers are generally built from commodity hardware developed for serving and surfing the web. When applied to cutting-edge problems in scientific computing, computers built from such general-purpose hardware usually spend most of their time moving data around in memory, and the hardware dedicated to floating point computations - that is, the actual addition and multiplication of numbers - spends most of its time idle. The small memory footprint of the new schemes developed at UC San Diego means that numerical problems of a given size will run much faster on a given computer, and that even larger numerical problems may be considered.

"Moving information around in memory is the bottleneck in almost all large-scale numerical simulations today", stated Thomas Bewley, a mechanical engineering professor who leads the Flow Control Lab at the Jacobs School of Engineering at UC San Diego. "The remarkable feature of the new family of schemes developed in this work is that they require significantly less memory in the computer for a given size simulation problem than existing high-order methods of the same class, while providing excellent numerical stability, accuracy, and computational efficiency."

Complex systems such as flows of fluids and plasmas generally evolve as a result of a combination of physical effects, such as diffusion and convection. Some of these effects are linear and incorporate many spatial derivatives - that is, they are characterized by a large range of characteristic time scales, and are thus referred to as "stiff". These terms are best handled with "implicit" methods, which require the solution of many simple simultaneous equations using matrix algebra and iterative solvers.

Other effects are nonlinear and incorporate fewer spatial derivatives - that is, they are characterized by a smaller range of characteristic time scales, and are thus referred to as "nonstiff". These terms are most easily handled with explicit methods, which treat the propagation of each equation independently. If the stiff terms are treated with explicit methods, a severe restriction arises on the timestep, which slows the simulation; if the nonstiff terms are treated with implicit methods, complex and computationally expensive iterative solvers must be used.

The new "implicit/explicit" or IMEX time marching schemes developed at UC San Diego thus marry together two algorithms for time-resolved simulations of the standard "Runge-Kutta" or RK form. The implicit algorithm is applied to the stiff terms of the problem, and the explicit algorithm is applied to the nonstiff terms of the problem. The two algorithms so joined are each endowed with good numerical properties, such as excellent stability and high accuracy, and, notably, maintain this high accuracy when working together in concert. The compatible pairs of simulation methods so developed are known as IMEXRK schemes.

"Searching for the right combination of the dozens of parameters that make these new IMEXRK algorithms work well was like finding a needle in a haystack, and required a tedious search over a very large parameter space, combined with the delicate codification of various numerical intuition to simplify the search. It took almost one year to complete", stated Daniele Cavaglieri, a Ph.D. student and co-author of the paper.

Researchers describe the new methods in the January 2015 issue of theJournal of Computational Physics. The paper "Low-storage implicit/explicit Runge-Kutta schemes for the simulation of stiff high-dimensional OED systems" is available at http://www.sciencedirect.com/science/article/pii/S0021999115000352 .
Source: University of California - San Diego

Back to Table of contents

Primeur weekly 2015-03-30

Exascale supercomputing

PRACEdays15 to include EESI2 Final Conference, Women in HPC, and Enabling Exascale in Europe ...

The Cloud

HP delivers first fully-configured and integrated OpenStack and Cloud Foundry-based private Cloud ...

Desktop Grids

BOINC 7.4.42 released to the public ...

EuroFlash

Altair Engineering announces keynote speakers from Airbus, Jaguar Land Rover and Bloodhound SSC to present at the 9th UK Altair Technology Conference ...

UK Atomic Weapons Establishment awards SGI contract to support research with new SGI ICE XA systems ...

Cray to deliver five-petaflop supercomputer and high-performance storage system to Petroleum Geo-Services ...

Theory of the Strong Interaction verified - Supercomputer calculates mass difference between neutron and proton ...

Lenovo opens first global High Performance Computing innovation centre in Germany ...

A rehearsal space with musicians 2,700 kilometers apart from each other ...

A first glimpse inside a macroscopic quantum state ...

USFlash

Automotive, aerospace and defense take centre stage at the 2015 Americas Altair Technology Conference ...

Big Data allows computer engineers to find genetic clues in humans ...

SGI delivers cutting-edge supercomputer to the National Institute for Materials Science ...

Supercomputers give universities a competitive edge, researchers find ...

Engineers develop new methods to speed up simulations in computational grand challenge ...

Micron and Intel unveil new 3D NAND flash memory ...

India's National Supercomputing Mission (NSM): Building capacity and capability to be jointly implemented by the Department of Science and Technology and Department of Electronics and Information Technology ...

U.S. Army improves systems testing to deliver more capability to fight ...

Quantum compute this - WSU mathematicians build code to take on toughest of cyber attacks ...

IBM invests in Modernizing Medicine to accelerate adoption of Watson technologies in health care ...

Quantum correlation can imply causation ...

From programmable backbones to advanced 'apps': An end-to-end vision of the future Internet ...

Building shape inspires new material discovery ...

UW scientists build a nanolaser using a single atomic sheet ...

OpenPOWER Foundation technology leaders unveil hardware solutions to deliver new server alternatives ...