Periodic Reporting for period 1 - YIELDGAP (YIELD-stress fluids beyond Bingham - closing the GAP in modelling real-world yield-stress materials)
Reporting period: 2021-01-01 to 2022-12-31
Combining clean environment with an economic growth in EU requires more efficient industrial processes. It is impossible to design cost-and resource-efficient yet safe processes and products, without measuring and predicting the flow behaviour of the materials that are processed. It is hence crucial to assist with a better characterization, modelling, formulation and processing of yield-stress fluids (YSFs) as well as understanding the role of additives (masterbatches, particles), to help the growth of both traditional and new key emerging industries in EU. Yield-stress fluids flow when a high-enough stress is applied to them, but behave as rigid or deformable solids otherwise. The force or stress required to initiate their flow along with their deformation history plays a significant role in the production, storage, transfer, packaging, and end-use performance of yield-stress materials. Examples of EU industries that are producing YSFs are: printing (ink), health care (e.g. pharmaceutics, toothpaste), building industry (concrete, paint, plaster, mortar), cosmetics (foams, creams and oils), food processing (numerous products, e.g. mayonnaise, peanut butter and chocolate), oil and gas (oils and mud drillings to be transported in pipelines). Moreover, our ability to predict and handle common natural disasters of great societal and environmental impact for the EU, such as mud slides, lava flows and avalanches, are associated with the yielding behaviour of this type of material.
Despite the abundance of yield-stress materials in industrial and natural processes, existing practices cannot predict even basic characteristics such as the minimal pressure drop needed to start a flow. A patchwork of approaches exists for modelling flows of YSFs, across different industries and academia, and there is no consensus to which models or measurements apply in which situations. Hence, the challenge of predicting the flows of YSFs cannot be solved by single research groups or existing networks, which focus on only a particular sector or aspect. YIELDGAP is a new multidisciplinary network aiming to (i) establish a coherent and efficient approach for the prediction of YSM flow in Europe, (ii) gather a sufficient database of material properties, models, computer simulations and measurements in order to develop new models and methods and establish guidelines for best practice, and (iii) consolidate the world-leading networks of scientific expertise which are necessary for solving these challenging issues, and (iv) to train a new generation of researchers who will apply the techniques across industrial sectors and academia in the EU in the coming years.
Despite the abundance of yield-stress materials in industrial and natural processes, existing practices cannot predict even basic characteristics such as the minimal pressure drop needed to start a flow. A patchwork of approaches exists for modelling flows of YSFs, across different industries and academia, and there is no consensus to which models or measurements apply in which situations. Hence, the challenge of predicting the flows of YSFs cannot be solved by single research groups or existing networks, which focus on only a particular sector or aspect. YIELDGAP is a new multidisciplinary network aiming to (i) establish a coherent and efficient approach for the prediction of YSM flow in Europe, (ii) gather a sufficient database of material properties, models, computer simulations and measurements in order to develop new models and methods and establish guidelines for best practice, and (iii) consolidate the world-leading networks of scientific expertise which are necessary for solving these challenging issues, and (iv) to train a new generation of researchers who will apply the techniques across industrial sectors and academia in the EU in the coming years.
Twelve (12) Early-Stage Researchers were recruited during the first year of the project to 7 beneficiaries who are at: KTH Royal Institute of Technology (Sweden), Chalmers University of Technology (Sweden), University of Bordeaux (France), ESPCI (France), INRAE (France), University of Naples (Italy) and University of Patras (Greece). In this period, all but one ESR have already started their secondments to academic or industrial partners. These secondments benefited the ESRs careers and PhD studies, and have resulted in many new collaborations within the consortium.
The two first YIELDGAP Graduate Schools, of 5 days each, were held during the first reporting period. The first School was organized by KTH (held digitally), and the second one was held at Capri, Italy, organized by UNINA. Following our plan, the ESRs and external participants were introduced to yield-stress materials, their physical and chemical properties, approaches to measure and characterize them in academia and industry, and existing modelling approaches from continuum (macroscale) to mesoscale. They have also learned transferrable skills, including communication and presentation, and report writing. In the remaining Schools, the ESRs will further deepen their technical skills, and prepare for bridging computational and experimental rheology and modelling, which will result in database and guidelines for prediction of YSFs.
The Early-Stage Researchers (ESRs) have been working on their PhD between 1-1.5 years by the time of this report, and together with academic and industrial partners have already made scientific progress in a wide variety of areas connected to the four scientific workpackages.
In WP3, 5 ESRs are working individually and together to improve computational models by including the following realistic effects in their models and software: time-dependent rheology (thixo-elasto-visco-plastic effects), particles, bubbles and droplets present in many real fluids, and complex geometries. A journal paper on particle sedimentation was published in Journal of Non-Newtonian Fluid Mechanics, and many conference presentations have been given.
In WP4, 5 ESRs are working collaboratively on how to measure relevant YSF properties and connect them to model parameters. Especially, they are quantifying how behaviours of real-world materials can be measured in a reliable way and connected to model parameters, both industrial materials such as yoghurt and mayonnaise, and work on designing lab fluids with controlled and tunable properties (yield stress, elasticity). Secondments have been conducted allowing ESRs to collaborate with each other and the industry.
In WP5, 4 ESRs are working on experimental validation of computational models, using lab fluids and industrial fluids. Here, we explore novel measurement techniques that can be used also for opaque fluids, characterisation of how YSFs slide over different surfaces (slip behaviour), and turbulent flows of YSFs. One journal paper has been published, and many conference presentations have been given.
In WP6, 2 ESRs are working on improved prediction of natural disasters (debris and lava flows) by developing computational methods for these challenging free-surface flows. A journal paper is under review and several conference presentations have been given.
The two first YIELDGAP Graduate Schools, of 5 days each, were held during the first reporting period. The first School was organized by KTH (held digitally), and the second one was held at Capri, Italy, organized by UNINA. Following our plan, the ESRs and external participants were introduced to yield-stress materials, their physical and chemical properties, approaches to measure and characterize them in academia and industry, and existing modelling approaches from continuum (macroscale) to mesoscale. They have also learned transferrable skills, including communication and presentation, and report writing. In the remaining Schools, the ESRs will further deepen their technical skills, and prepare for bridging computational and experimental rheology and modelling, which will result in database and guidelines for prediction of YSFs.
The Early-Stage Researchers (ESRs) have been working on their PhD between 1-1.5 years by the time of this report, and together with academic and industrial partners have already made scientific progress in a wide variety of areas connected to the four scientific workpackages.
In WP3, 5 ESRs are working individually and together to improve computational models by including the following realistic effects in their models and software: time-dependent rheology (thixo-elasto-visco-plastic effects), particles, bubbles and droplets present in many real fluids, and complex geometries. A journal paper on particle sedimentation was published in Journal of Non-Newtonian Fluid Mechanics, and many conference presentations have been given.
In WP4, 5 ESRs are working collaboratively on how to measure relevant YSF properties and connect them to model parameters. Especially, they are quantifying how behaviours of real-world materials can be measured in a reliable way and connected to model parameters, both industrial materials such as yoghurt and mayonnaise, and work on designing lab fluids with controlled and tunable properties (yield stress, elasticity). Secondments have been conducted allowing ESRs to collaborate with each other and the industry.
In WP5, 4 ESRs are working on experimental validation of computational models, using lab fluids and industrial fluids. Here, we explore novel measurement techniques that can be used also for opaque fluids, characterisation of how YSFs slide over different surfaces (slip behaviour), and turbulent flows of YSFs. One journal paper has been published, and many conference presentations have been given.
In WP6, 2 ESRs are working on improved prediction of natural disasters (debris and lava flows) by developing computational methods for these challenging free-surface flows. A journal paper is under review and several conference presentations have been given.
The YIELDGAP ITN-ETN programme targets to provide answers to burning questions in this research field, bridge the gaps and enhance the synergy between industry and academia, and create (i) a database of material properties, models and measurements and (ii) best practice guidelines for modelling of Yield-Stress Fluids (YSFs).
The 12 ESRs are already taking steps to enhance our understanding of yield-stress fluids (as detailed in the section above) and the results have already been disseminated in journal publications, 14 scientific conferences and 3 university/laboratory open days.
We are expecting that fundamental modelling and industrial processing of yield-stress fluids will continue to improve by the YIELDGAP programme which gathers leading experts in all aspects of YSFs who will together train a new generation of researchers for Europe. These Early Stage Researchers (ESRs) will generate and disseminate knowledge and become versatile and multidisciplinary future leaders in the design of processes using complex fluids in academia and industry. Their education includes cutting-edge concepts of industrial design, the most advanced experimental techniques and numerical models, chemistry and flow dynamics. This will give the YIELDGAP researchers a unique ability to bridge the yield gap – a gap between academic models and industrial engineering practice, and a gap between the predicted and the measured characteristics of real industrial flows.
The 12 ESRs are already taking steps to enhance our understanding of yield-stress fluids (as detailed in the section above) and the results have already been disseminated in journal publications, 14 scientific conferences and 3 university/laboratory open days.
We are expecting that fundamental modelling and industrial processing of yield-stress fluids will continue to improve by the YIELDGAP programme which gathers leading experts in all aspects of YSFs who will together train a new generation of researchers for Europe. These Early Stage Researchers (ESRs) will generate and disseminate knowledge and become versatile and multidisciplinary future leaders in the design of processes using complex fluids in academia and industry. Their education includes cutting-edge concepts of industrial design, the most advanced experimental techniques and numerical models, chemistry and flow dynamics. This will give the YIELDGAP researchers a unique ability to bridge the yield gap – a gap between academic models and industrial engineering practice, and a gap between the predicted and the measured characteristics of real industrial flows.