The vertebral column represents an essential element for support, mobility, and the protection of the central nervous system. Various pathologies can compromise these vital functions, leading to pain ...and a decrease in the quality of life. Within the scope of this study, a novel redesign of the Intersomatic Cage, traditionally used in the presence of discopathy, was proposed. The adoption of additive manufacturing technology allowed for the creation of highly complex geometries, focusing on the lumbosacral tract, particularly on the L4-L5 and L5-S1 intervertebral discs. In addition to the tensile analysis carried out using Finite Element Analysis (FEA) in static simulations, a parallel study on the range of motion (ROM) of the aforementioned vertebral pairs was conducted. The ROM represents the relative movement range between various vertebral pairs. The introduction of the intersomatic cage between the vertebrae, replacing the pulpy nucleus of the intervertebral disc, could influence the ROM, thus having significant clinical implications. For the analysis, the ligaments were modelled using a 1D approach. Their constraint reaction and deformability upon load application were analysed to better understand the potential biomechanical implications arising from the adoption of the cages. During the FEA simulations, two types of cages were analysed: LLIF for L4-L5 and ALIF for L5-S1, subjecting them to four different loading conditions. The results indicate that the stresses exhibited by cages with a NET structure are generally lower compared to those of traditional cages. This stress reduction in cages with NET structure suggests a more optimal load distribution, but it is essential to assess potential repercussions on the surrounding bone structure.
•Demonstrate 3D CFD of buoyancy-driven convection flow resolved on a full-geometry passenger car.•A transient CFD - heat transfer modelling predicted cool-down behaviours during the static ...soak.•Additional heat retention benefits characterised with vehicle-mounted-encapsulation design.•A cost-effective CAE tool developed for heat retention analysis and encapsulation design.•The CAE will aid the design development to achieve reduced CO2 emissions and fuel consumption.
This paper investigates high fatality modelling of vehicle heat transfer process during natural soak environment and heat retention benefits with powertrain encapsulations. A coupled computer-aided-engineering (CAE) method utilising 3D computational-fluids-dynamics (CFD) and transient thermal modelling was applied to solve buoyancy-driven convection, thermal radiation and conduction heat transfer of vehicle structure and fluids within. Two vehicle models with different encapsulation layouts were studied. One has engine-mounted-encapsulation (EME) and the other has additional vehicle-mounted-encapsulation (VME). Coupled transient heat transfer simulations were carried out for the two vehicle models to simulate their cool-down behaviours of 9 h static soak. The key fluids temperatures’ cool-down trajectories were obtained and correlated well with vehicle test data. Increased end temperatures were seen for both coolant and oils of the VME model. This provides potential benefits towards CO2 emissions reduction and fuel savings. The air paths and thermal leakages with both encapsulations were visualised. Reduced leakage pathways were found in the VME design in comparison with the EME design. This demonstrated the capability of embedded CAE encapsulation heat retention modelling for evaluating encapsulation designs to reduce fuel consumption and emissions in a timely and robust manner, aiding the development of low-carbon transport technologies.
•3D CFD modelling of buoyancy-driven convection flow resolved on full-geometry vehicle.•Convective heat transfer coefficients characterised during natural soak environment.•Coupled transient CFD - ...heat transfer modelling analysis was demonstrated.•9 h cool-down behaviours of the key engine fluids were resolved.•A CAE tool developed enabling evaluations of heat retention and encapsulation design.
This paper investigates transient heat transfer processes of a vehicle under-bonnet region during natural soak condition using computer aided engineering (CAE). Heat reserved within the engine bay is beneficial to the engine cold-start for potentially reductions in friction losses, CO2 emissions and fuel consumption. Buoyancy-driven convection, thermal radiation and conduction are key contributors to heat transfer processes of engine compartments during soak. In this study, a coupled transient 3D computational fluids dynamics (CFD) – heat transfer modelling method was studied in a passenger vehicle to simulate its 9 h cool-down behaviours. The developed CAE method was able to predict the temperature cool-down of the key fluids of good agreement with experiments. Potential air and heat leakage paths around the engine bay were identified. The flow development during the early stage (0–2 h) of the soak was vital to accurate prediction of the heat transfer coefficients for the heat retention modelling, where convection and radiation have played important parts. Optimum simulation strategy was obtained with reduced simulation time and good prediction accuracy. This further allows the integration of engine encapsulation design for optimising fuel consumption and emissions in a timely and robust manner, aiding the development of low-carbon transport technologies.
A non-parametric model was proposed for modelling the influence of different technological and chemical parameters on the mechanical properties of the 6082 aluminium alloys during the hot extrusion ...process with a special consideration of human factor. It was shown that human factor (influence of process engineers) was important and that it could be efficiently modelled and taken into account by the proposed Conditional Average Estimator (CAE) method. Production might be improved (optimized) by a proper education and/or by eliminating critical process engineers. It was found that the highest values for elongation and yield stress did not coincide with the range of the most frequent combinations of input parameters.
Predložen je neparametarski model za modeliranje utjecaja različitih tehnoloških i kemijskih parametara na mehanička svojstva aluminijske legure 6082 tijekom istiskivanja na toplo s posebnim ...razmatranjem na ljudskom faktorom. Pokazano je, da je ljudski faktor (utjecaj proces inženjera) važan i da se može efikasno uzeti u obzir s predloženom CAE metodom. Proizvodnja se može poboljšati (optimirati) uz odgovarajuće obrazovanje i/ili uklanjanje kritičnih proces inženjera. Zapaženo je, da se najviše vrijednosti produljenja i naprezanja tečenja ne podudaraju s područjem najčešćih kombinacija ulaznih parametara.
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