Anisotropic particles in turbulence: status and outlook

Abstract

Our motivation to publish a special journal issue focusing on various aspects of anisotropic particles in turbulent flows arose during the EUROMECH Colloquium 513 on Dynamics of non-spherical particles in fluid turbulence held at CISM (International Centre for Mechanical Sciences) in Udine in April 2011. The 42 participants came from rather diverse fields of research all along the route from curiosity-driven research on generic phenomena to investigations addressing industrial needs. The practical applications were intentionally biased towards fibre suspension flows since the colloquium was co-organized by ERCOFTAC’s Special Interest Group (SIG43) focussing on the several issues involved in fibre suspensions. Besides conventional paper manufacturing [1], wood crushed down into fibres and transported as a water suspension in pipes is part of the process of producing new products from forest fibres, such as micro-fibrillated cellulose (MFC), nano-crystalline cellulose (NCC), and ethanol. We, as the colloquium organizers, appreciated the benefits of bringing together scientists concerned with the dynamics of non-spherical particles in fluid flow, irrespective of their driving motivation and independent of their approach, be it modelling, experimental or simulation-based research. In accordance with the traditions of EUROMECH colloquia, no proceedings were published. Nevertheless, we found it timely to make a collection of current research achievements in the field of anisotropic particles in turbulence available to a wider audience. In 2012, invitations were sent to several research groups with a well-established activity in the field to contribute a paper to this special issue of Acta Mechanica. To our great pleasure, almost all of the invitees were able to accept the invitation and submitted their works in the late fall. All manuscripts were then subject to evaluation by anonymous reviewers as per the regular publication procedure in Acta Mechanica. Altogether, 13 reviewed and revised papers are published in this special issue. The papers focus on the different physical, modelling and measuring issues emerging when examining the behaviour of anisotropic particles in a turbulent environment. The dynamics of spherical (isotropic) particles has been extensively studied over the years. Studies of anisotropic particles are more scarce although dilute or