Caroline Nore, Houda Zaidi, Frederic Bouillault, Alain Bossavit and Jean-Luc Guermond
The purpose of this paper is to present a new formulation for taking into account the convective term due to an imposed velocity field in the induction equation in a code based on…
Abstract
Purpose
The purpose of this paper is to present a new formulation for taking into account the convective term due to an imposed velocity field in the induction equation in a code based on Whitney elements called DOLMEN. Different Whitney forms are used to approximate the dependent variables. The authors study the kinematic dynamo action in a von Kármán configuration and obtain results in good agreement with those provided by another well validated code called SFEMaNS. DOLMEN is developed to investigate the dynamo action in non-axisymmetric domains like the impeller driven flow of the von Kármán Sodium (VKS) experiment. The authors show that a 3D magnetic field dominated by an axisymmetric vertical dipole can grow in a kinematic dynamo configuration using an analytical velocity field.
Design/methodology/approach
Different Whitney forms are used to approximate the dependent variables. The vector potential is discretized using first-order edge elements of the first family. The velocity is approximated by using the first-order Raviart-Thomas elements. The time stepping is done by using the Crank-Nicolson scheme.
Findings
The authors study the kinematic dynamo action in a von Kármán configuration and obtain results in good agreement with those provided by another well validated code called SFEMaNS. The authors show that a 3D magnetic field dominated by an axisymmetric vertical dipole can grow in a kinematic dynamo configuration using an analytical velocity field.
Originality/value
The findings offer a basis to a scenario for the VKS dynamo.
Details
Keywords
Passages, seasons, turning points—all of these popular terms refer to periods of transition in our lives. I am careful to say “our lives” because these stages are universal; for…
Abstract
Passages, seasons, turning points—all of these popular terms refer to periods of transition in our lives. I am careful to say “our lives” because these stages are universal; for the most part, they are expected and accepted.
“All things are in a constant state of change”, said Heraclitus of Ephesus. The waters if a river are for ever changing yet the river endures. Every particle of matter is in…
Abstract
“All things are in a constant state of change”, said Heraclitus of Ephesus. The waters if a river are for ever changing yet the river endures. Every particle of matter is in continual movement. All death is birth in a new form, all birth the death of the previous form. The seasons come and go. The myth of our own John Barleycorn, buried in the ground, yet resurrected in the Spring, has close parallels with the fertility rites of Greece and the Near East such as those of Hyacinthas, Hylas, Adonis and Dionysus, of Osiris the Egyptian deity, and Mondamin the Red Indian maize‐god. Indeed, the ritual and myth of Attis, born of a virgin, killed and resurrected on the third day, undoubtedly had a strong influence on Christianity.
John Overby, Mike Rayburn, Kevin Hammond and David C. Wyld
The war in Iraq, the threat of terrorism and the Severe Acute Respiratory Syndrome (SARS) epidemic have made international business activities increasingly difficult and risky…
Abstract
The war in Iraq, the threat of terrorism and the Severe Acute Respiratory Syndrome (SARS) epidemic have made international business activities increasingly difficult and risky. The worldwide economic downturn and slow growth in domestic markets are forcing companies to depend more than ever on overseas trade. SARS emerged in China in November 2002 and has spread to 26 countries. The SARS epidemic has caused the most severe economic crisis in Southeast Asia since the wave of bank failures and currency devaluations that swept the region five years ago. The SARS epidemic has prompted health officials to implement travel advisories and restrictions, in order to defer nonessential travel to regions of Asia with large numbers of SARS cases. They are enforcing quarantine and isolation measures in major cities to try and limit the spread of SARS. The President of the United States has signed an executive order adding SARS to the list of communicable diseases that can be quarantined. A major disruption in China could paralyze just‐in‐time supply chains and cause an economic crisis for retailers and other businesses worldwide. The SARS epidemic has caused many economists to drastically reduce their economic‐growth forecasts for Asia. New infectious diseases, such as SARS, can emerge and easily travel around the globe, infecting less‐resilient hosts and mutating because of the influence of viruses and bacteria in their new environment. Health officials are even more concerned about the pandemic disaster that hasn’t happened, but may still. However, the SARS epidemic has created positive economic benefits for some companies.