Cooling of 3D printed tool for Aluminium casting
Developing an innovative methodology for designing a conformal cooling channel embedded in a 3D-printed HPDC tool for aluminium parts of complex geometries.
Led by Dr Ran Holtzman, our group combines analytical, experimental and numerical methods to gain fundamental understanding and establish quantitative models of various phenomena in which fluid mechanics is key.
Our research interests include mass and heat transfer, multiphase and reactive flow in porous media, turbulence, aerodynamics, magnetohydrodynamics, combustion, and biomechanics.
Our research aims to advance a variety of engineering applications ranging across scales, from microfabrication and biological flows, 3-D printing, microfluidics and filters, to water resources, geohazards, enhanced hydrocarbon recovery, carbon geosequestration and renewable energy systems.
A wine stain spreading across a tablecloth or oil percolating into wet sand are examples of a fluid displacing another in a porous material.
The way fluids move and the associated enchanting invasion patterns are scientifically and technologically important, as they help us to understand how to control the efficiency of processes such as oil production, removal or storage of contaminant in the subsurface, or fluid mixing in microfluidics.
However, despite this importance and the great scientific and technological interest, modelling of how fluids flow in porous media remains elusive. A major challenge is that many of the processes occur at the scale of individual pores (sizes of the order of millimetres), whereas the phenomena of interest are often at the scale of meters and even kilometres.
In recent projects, we combine novel controlled experiments, numerical simulations and theoretical analysis to expose the impact of wettability (Phys. Rev. Lett. 2015; PNAS 2019), the interplay of wettability and microstructural heterogeneity (Nature Sci. Rep. 2016), and the role of spatially-correlated heterogeneity in both forced fluid displacement (Adv. Water Resour. 2019) and isothrmal drying (Water Resour. Res. 2017; Nature Sci. Rep. 2017; Phys. Rev. Fluids 2018). We examine the origins of wetting-dewetting hysteresis, linking between microscopic capillary instabilities, energy dissipation and avalanches and the macroscopic pressure-saturation hysteretic response (Nature Commun. Physics 2020).
This is a 3-year Innovate UK project in collaboration with CastAlum, Renishaw and the Centre for Fluid and Complex Systems, with the aim to develop a full thermal and optimisation model to design cooling channels in a direct metal laser sintered (DMLS) steel tool for high pressure aluminium die-casting (HPADC).
The objective is to develop a new methodology to enhance the design of the printed tool component, using Renishaw’s 3D printing technology, to increase the potential number of units that can be cast at CastAlum to a possible 150,000 units for a given mould. At the same time, the intention is to ensure that CastAlum’s printed and optimally cooled tool can maintain the quality and compliance of the cast parts within the critical specifications of their automotive manufacturer’s supply chain.
The thermal model is to be validated using experimental data that are collected from a test rig facility built at our research centre, and the tools available at CastAlum. The new method allows the building of a baseline design and optimisation by changing the cooling channel cross section and shape locally depending on the heat flux, to meet the optimisation criteria.
The new approach will be used for various cooling systems that employ 3D printing capability. The project is led by Dr Essam Abo-Serie and Dr James Jewkes, and includes Tongyan Zeng as a PhD student and Yuancheng Liang as a Research Assistant.
In the automotive industry, porous medium filtration is used in particulate filters to remove toxic emissions.
The two- (sometimes three-) phase flow in such filters exhibits a range of complex features (e.g. flow separation, soot accumulation, slip effect), and our group has provided a range of reduced dimension models to facilitate cost-effective filter design.
We were the first to demonstrate that the turbulent flow may be present in the filter under certain conditions, and developed an extension to the established flow loss model taking into account transition to turbulence.
Our joint projects with Jaguar Land Rover led to a range of publications, including:
Our group also leads the Special Interest Group in Particulate Matter Filtration Flows (part of the EPSRC funded UK Fluids network).
If you wish to find out more about this theme, please get in contact with Dr Svetlana Aleksandrova.
Multiphase and reactive fluid flow in porous media is often unstable, and highly heterogeneous: inevitable microstructural heterogeneity leads to the emergence of preferential pathways, where most of the flow is focused in a small portion of the medium. Furthermore, strong hysteresis (Nature Commun. Physics 2020) and rate-dependence (Phys. Rev. Lett. 2015; Adv. Water Resour. 2019; PNAS 2019) are frequently observed.
This complex, out-of-equilibrium behaviour is further corroborated by interactions between the fluids and the solid matrix, for example, fracturing (Phys. Rev. Lett. 2012; Int. J. Heat Mass Transf. 2020) and dissolution (Earth Planet. Sci. Lett. 2018; Water Resour. Res. 2020).
We combine experiments, simulations and theory to understand the pore-scale physics underlying nonequilibrium flows in porous media, and its implications on engineering problems, mainly in the field of energy and the environment.
The group has a keen interest in biological flows, which includes both cardiovascular system and flow in human airways. Our recently initiated collaboration with Imperial College London resulted in a fully-funded joint PhD project on airway flow validation techniques (starting in January 2021).
Another GCRF funded PhD project (January 2021) will study modelling particle transport in human airways, as an extension of our commitment to air quality agenda stemming from the industrial collaboration on automotive aftertreatment.
A new PhD project, in collaboration with Misal company, will also start in January 2021 to characterise the flow and performance of an innovative Intra-Aorta pump that can replace the current heart assist devices that require open heart surgery and lead to partial heart damage.
If you wish to find out more about this theme, please get in contact with Associate Professor Ran Holtzman.
The growing concern over reduction of CO2 emissions resulted in a major trend of downsizing the car engines, with turbocharging being one of the most developed technologies.
This presents a new challenge for roxic emission aftertreatment system designers as the swirling motion introduced by the turbocharger turbine will affect flow distribution inside the catalyst and thus its performance.
Our research uses experimental and modelling techniques to study the effect of the swirl on the flow inside the catalyst, focussing on the flow uniformity and CFD model assessment. However, swirl is important in many other applications, and we are also applying our expertise to the area of using swirl for water and air filtration, which is the topic of the PhD project funded by GCRF starting in January.
If you wish to find out more about this theme, please get in contact with Dr Svetlana Aleksandrova.
Our group has extensive expertise in nozzle flow and spray characterisation using optical and laser techniques using LDV and PIV systems. Atomization and evaporation processes are critical in many engineering applications, particularly to have efficient combustion and low emissions in aircraft and automotive engines.
Team members have worked in various industrial projects that included industrial companies, such as Siemens, Bosch and Rolls Royce. Our work on Selective Catalytic Reduction in collaboration with Jaguar Land Rover, Johnson Matthey and other partners resulted in an EPSRC project “Modelling NOx reduction by selective catalytic reduction (SCR) appropriate for light-duty vehicles under steady state and transient conditions” (EP/F036175/1). The project provided validation data for a new model of urea droplet dispersion, evaporation and thermolysis, in both steady and transient states, along with models for SCR kinetics over a Cu zeolite catalyst.
Contact Dr Essam Abo-Serie if you need further information.
Name | Title | Areas of expertise | |
---|---|---|---|
Ran Holtzman | Associate Professor, Theme Lead | Multiphase and reactive flows in porous and granular media, emphasizing nonequilibrium, instabilities, preferential pathways, and coupling with matrix deformation | Ran.Holtzman@coventry.ac.uk |
Essam Abo-Serie | Assistant Professor, School of Mechanical, Aerospace and Automotive Engineering | Thermofluids systems analysis using experimental and modelling techniques | Essam.Abdelfatah@coventry.ac.uk |
Svetlana Aleksandrova | Assistant Professor | Computational and experimental fluid dynamics, magnetohydrodynamics, filtration flows, swirling flows, biological flows | S.Aleksandrova@coventry.ac.uk |
Jonathan Carter | Assistant Professor, School of Energy, Construction and Environment | Uncertainty quantification, decision making under uncertainty | Jonathan.Carter@coventry.ac.uk |
James Jewkes | Assistant Professor, School of Mechanical, Aerospace and Automotive Engineering | CFD (RANS, LES and DNS), turbulent flows (boundary layers and jets), automotive aerodynamics, shape-optimisation (kriging and adjoint methods), heat transfer, and biomechanics (computational haemodynamics) | James.Jewkes@coventry.ac.uk |
Humberto Medina | Assistant Professor | Computational and experimental fluid dynamics, Transitional flow, Porous filters | Humberto.Medina@coventry.ac.uk |
Jonathan Nixon | Assistant Professor, School of Mechanical, Aerospace and Automotive Engineering | Energy systems modelling and optimisation, wind, solar and bio- energy engineering, decentralised energy and multi-criteria decision analysis | Jonathan.Nixon@coventry.ac.uk |
Seyed Shariatipour | Senior Lecturer in Petroleum Reservoir Management | Experimental studies and numerical modelling of fluid flow in porous media; in particular, CO2 storage in geological formations and CO2 Enhanced Oil Recovery (CO2-EOR) | Seyed.Shariatipour@coventry.ac.uk |
Our projects evolve around the application of basic fluid dynamics concepts to a variety of applications across scales.
Examples range from microfabrication and 3-D printing, microfluidics, filters, and biological flows, to water resources, geohazards, enhanced hydrocarbon recovery, carbon geosequestration and renewable energy systems.
Find out more about some of our projects:
Developing an innovative methodology for designing a conformal cooling channel embedded in a 3D-printed HPDC tool for aluminium parts of complex geometries.
Making the standard models required for the testing and comparison of petroleum reservoir engineering modelling techniques available at a single location.
This special interest group (part of the UK Fluids network) brings together industry, academia and policy makers to boost research in filtration flows in automotive and marine applications.