Design Optimisation of the Feeding System of a Novel Counter-Gravity Casting Process

Abstract

The appropriate design of feeders in a rigging system is critical for ensuring efficient compensation for solidification shrinkage, thus eliminating (shrinkage-related) porosity and contributing to the production of superior quality castings. In this study, a multi-objective optimisation framework combined with Computational Fluid Dynamics (CFD) simulations has been introduced to investigate the effect of the feeders’ geometry on shrinkage porosity aiming to optimise casting quality and yield for a novel counter-gravity casting process (CRIMSON). The weighted sum technique was employed to convert this multi-objective optimisation problem to a single objective one. Moreover, an evolutionary multi-objective optimisation algorithm (NSGA-II) has been applied to estimate the trade-off between the objective functions and support decision makers on selecting the optimum solution based on the desired properties of the final casting product and the process characteristics. This study is one of the first attempts to combine CFD simulations with multi-objective optimisation techniques in counter-gravity casting. The obtained results indicate the benefits of applying multi-objective optimisation techniques to casting processes.

Numerical Simulation and Evaluation of Campbell Running and Gating Systems

“…The mold material was considered to be sand silica. Only half of the simulation domain was simulated by exploiting symmetry boundary conditions in order to reduce the computational cost [17]. The only exception was the VG design which is asymmetric, so in this case the whole domain was simulated.…”

“…A concrete review of the numerical models implemented for modelling entrainment defects is given in [14]. Nowadays, CFD models are being used in conjunction with design of experiments (DoE) methods [15,16] and optimisation schemes [17,18] in order to eliminate defective locations in castings by altering process parameters such as the pouring temperature or geometrical parameters of the running, feeding, and gating systems.…”

Optimization of Industrial Casting Processes

“…Switching to near-net-shape casting, in the study by Papanikolaou et al [5], a multi-objective optimization framework was combined with computational fluid dynamics (CFD) simulations to investigate the effect of the feeder(s) geometry on shrinkage porosity, the goal being to optimize casting quality and yield for a novel counter-gravity casting process (CRIMSON). The weighted sum technique was employed to convert this multi-objective optimization problem to a single objective one.…”

Substitution of cast iron engine components with aluminium alloys: A life cycle perspective

“…According to the results presented in the previous sections, the need for a full assessment of the energy requirements and CO2 emissions of the "manufacturing" and "use" phases of a component is more than imperative before deciding to substitute currently used materials with so-called lighter ones. Therefore, performing numerical optimization in order to simultaneously maximize the yield of manufacturing processes as well as the quality of the final cast product could be a trustworthy alternative solution [20]. Moreover, decision support tools need to be developed in order to assist design and foundry engineers to select the most appropriate material for a particular application with respect to minimizing the energy requirements and CO2 emissions of the "manufacturing" and "use" phases of the product.…”