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Primeur weekly 2018-03-19

Exascale supercomputing

BSC and Fujitsu to build up an ecosystem for a future exascale supercomputer ...

Quantum computing

New quantum spin liquid predicted by Nobel Laureate prepared for the first time ...

Focus on Europe

New project to plug the software-stack support gap for energy-efficient computing ...

North German scientists receive new supercomputer in the HLRN network ...

Hardware

Cray tapped to deliver largest supercomputer dedicated to fusion science in Japan by National Institutes for Quantum and Radiological Science and Technology ...

Keeping GPUs young ...

Asetek announces ongoing collaboration with Intel on liquid cooling for servers and data centres ...

UC San Diego Center for Microbiome Innovation announces Panasas as Corporate Member ...

Cavium expands industry partnerships to drive OCP NIC 3.0 ...

Applications

How much snow accumulates in North America each year? More than scientists thought. ...

Green light for Galaxy Europe ...

Supercomputer simulation opens prospects for obtaining ultra-dense electron-positron plasmas ...

The complex journey of red bloods cells through microvascular networks ...

The view from inside supersonic combustion ...

A game changer: Metagenomic clustering powered by supercomputers ...

ORNL researchers design novel method for energy-efficient deep neural networks ...

University of Texas researchers develop new visualization tools to explore fusion physics ...

Fishing with simulations for two-dimensional materials ...

The Cloud

IBM helps accelerate AI with fast new data platform and elite team ...

European Commission to adopt Implementation Roadmap for the European Open Science Cloud ...

Univa announces a global partnership and reseller agreement with UberCloud ...

Univa open sources Project Tortuga to accelerate the migration of enterprise HPC workloads to the Cloud ...

USFlash

Xilinx unveils revolutionary adaptable computing product category ...

The view from inside supersonic combustion


Instantaneous distributions of dimensionless temperature T/T0 and fuel mass fraction, with blue dashed lines given by YF=0.05: (top, Case LP-OS1) weak shock with stoichiometric mixture, (middle, Case LP-OS2) strong shock with stoichiometric mixture, and (bottom, Case LP-OS2-H) strong shock with fuel-rich mixture. Here, the gray dots indicate evaporating fuel droplets. Credit: Zhaoxin Ren, Bing Wang and Longxi Zheng.
15 Mar 2018 Washington, D.C. - In a jet engine, the flow of air is slowed down to increase the temperature and pressure for combustion - burning fuel with the right ratio of fuel and air to conquer drag allows for acceleration.

But in supersonic engines achieving the right flow speed, producing the right ratio of evaporated fuel and causing ignition at the right time is more complex. With evaporating liquid in a combustion chamber, there is more at play than just gravity and drag, especially with supersonic shock waves in the equation.

Vortices - the dynamic structures created in a turbulent flow - are affected by the shock wave. This changes the way the fuel combusts and multiplies the number of possibilities of how particles can behave. To deepen our understanding of the dynamics of supersonic flow, researchers look to numerical modelling to calculate the huge variety of possible outcomes in this changed system.

In their study, published inPhysics of Fluids, by AIP Publishing, Zhaoxin Ren, Bing Wang and Longxi Zheng viewed supersonic combustion in a time series through numerical modelling. This allowed them to see how changing variables, such as mass loading fuel, the intensity of the shock wave, and the types of reflecting and transmitted waves created at different points in time will affect ignition.

They were able to quantitatively characterize the influence of an incident oblique shock wave on large-scale shearing vortices and exothermal reactions, mathematically mapping the influence of variables and the resulting types of waves created in a shocked gas. Their analysis establishes a reliable simulation method for supersonic combustion using mathematical modeling tools specifically designed for this purpose.

"Currently, no commercial software can simulate the supersonic combustion problem because it requires high-order numerical schemes to compute supersonic flows with complicated evolved shocks, as well as corrected models to describe the droplet dynamics, both of which we carefully consider in our in-house simulation codes", Bing Wang stated, a co-author of the study. "Direct numerical simulation can capture the full scales of flows involved in the shock-vortex interaction."

Using a combination of custom simulation codes and the Eulerian-Lagrangian method commonly applied to particle-laden two-phase flows, the authors were able to run a broad range of simulations and provide a series of test cases that inform scramjet engine design. Their analysis revealed two induced combustion modes, including a local quasi detonation mode that occurs due to the formation of a refracted wave coupled with the chemical reaction.

"The scramjet engine is the most favorable option for high-speed flight at Mach six or more", Bing Wang stated. "Understanding the complicated physical mechanism of supersonic combustion and the impact of incident shock waves could help engineers choose the best combination of mixing and combustion through installing movable components in the combustor."

The article, " Numerical analysis on interactions of vortex, shock wave and exothermal reaction in a supersonic planar shear layer laden with droplets ", is authored by Zhaoxin Ren, Bing Wang and Longxi Zheng. The article appeared inPhysics of Fluids, March 13, 2018.

Source: American Institute of Physics

Back to Table of contents

Primeur weekly 2018-03-19

Exascale supercomputing

BSC and Fujitsu to build up an ecosystem for a future exascale supercomputer ...

Quantum computing

New quantum spin liquid predicted by Nobel Laureate prepared for the first time ...

Focus on Europe

New project to plug the software-stack support gap for energy-efficient computing ...

North German scientists receive new supercomputer in the HLRN network ...

Hardware

Cray tapped to deliver largest supercomputer dedicated to fusion science in Japan by National Institutes for Quantum and Radiological Science and Technology ...

Keeping GPUs young ...

Asetek announces ongoing collaboration with Intel on liquid cooling for servers and data centres ...

UC San Diego Center for Microbiome Innovation announces Panasas as Corporate Member ...

Cavium expands industry partnerships to drive OCP NIC 3.0 ...

Applications

How much snow accumulates in North America each year? More than scientists thought. ...

Green light for Galaxy Europe ...

Supercomputer simulation opens prospects for obtaining ultra-dense electron-positron plasmas ...

The complex journey of red bloods cells through microvascular networks ...

The view from inside supersonic combustion ...

A game changer: Metagenomic clustering powered by supercomputers ...

ORNL researchers design novel method for energy-efficient deep neural networks ...

University of Texas researchers develop new visualization tools to explore fusion physics ...

Fishing with simulations for two-dimensional materials ...

The Cloud

IBM helps accelerate AI with fast new data platform and elite team ...

European Commission to adopt Implementation Roadmap for the European Open Science Cloud ...

Univa announces a global partnership and reseller agreement with UberCloud ...

Univa open sources Project Tortuga to accelerate the migration of enterprise HPC workloads to the Cloud ...

USFlash

Xilinx unveils revolutionary adaptable computing product category ...