Mechanical properties of cohesionless and cohesive bulk solids: transition from non-cohesive to cohesive powders

Granular material is ubiquitous in nature, constituting over 75% of the raw materials used as feedstock in a breadth of industries. Powders and bulk solids not only play a significant role in industrial production and development of novel technologies, it is also directly related to environmental sustainability and public health. With such relevance in industry for centuries, difficulty in predicting their mechanical behavior however poses a challenge towards achieving higher efficiency and production rates in many industrial processes. Thus the characterization of flow properties in powders and bulk solids can enable implementation of credible numerical models to simulate crucial industrial processes, which can potentially save valuable resources, energy and time. Recent advances in nanomaterials have led to development in novel technology and new products. However, the risk posed by many such materials and products are not yet known and hence their characterization can not only promote occupational health and safety but also save valuable resources. 

The research project in the form of a doctoral program aims to characterize mechanical properties of cohesive and non-cohesive bulk solids to enable simulation of such materials. It will involve basic and advanced scientific training in related topics including continuum mechanics, fluid mechanics, particle technology, bulk material testing, bulk process design and cohesion & adhesion. Material properties at bulk scale will be characterised using standard industrial tests, as an input for particle simulations using DEM-CFD. Sets of experimental tests will also be conducted to analyse the transition from non-cohesive to cohesive powder properties. 

The program aims to develop the existing classical shear tester (Jenike tester) for bulk solids, into an automatic translational shear tester, which can enable accurate testing of bulk solids in nano-scale. Calibration of this tester will be done with respect to the shear testers installed at the TU Braunschweig and the BASF headquarters in Ludwigshafen. The shear tester will enable parametric study of nanopowders and their dustiness which will be critically analysed using the state-of-the-art laboratory and equipment at the National Institute for Industrial Environment and Risks (INERIS), France. It is planned to develop constitutive numerical models using DEM-CFD at the University of Twente, which will be implemented to simulate the aerosolization process of nanopowders. Finally, the tested bulk solids will be classified with respect to their emission risk, leading to control banding of such materials.

Somik Chakravarty


Nationality: Indian

Current Stay: Université de Technologie de Compiègne, Compiègne - France

I obtained my Bachelors in Mechanical Engineering from the University of Sheffield followed by a Masters in Thermal Power and Fluids Engineering from the University of Manchester in United Kingdom. Before joining the T-MAPPP program, I was working as a Research assistant at Amity University, India in the field of using localized surface plasmon resonance (LSPR) in metal nanoparticles in enhancing efficiency of thin-film solar cells. My interest in fine and nano-scale particles and their immense potential in scientific research motivated me to be a part of the T-MAPPP program. Under the supervision of Dr Martin Morgeneyer, my research will involve characterization of flow properties of bulk solids with an emphasis on fine and nano-scale powders. The research project also focuses on characterization of parameters which influences aerosolization of potentially hazardous dust generated from handling and processing of nanomaterials in industrial workplaces. 

Somik Chakravarty