Fabrizio Dughiero

Numerical FEM Models for the Planning of Magnetic Induction Hyperthermia Treatments With Nanoparticles

A numerical FEM model of a magnetic fluid hyperthermia (MFH) treatment on an hepatocellular carcinoma (HCC) metastasis has been simulated. Starting from actual CT images of the patient, a 3-D geometry of the anatomical district has been reconstructed and a coupled electromagnetic and thermal transient analysis has been performed, in order to predict the temperature distribution during the treatment. The in vivo effect of blood perfusion has also been implemented through the Penness model. Various simulations have been carried out, based on different particle sizes and concentrations, as well as different exciting field intensities.

Proximity effect and magnetic field calculation in GIL and in isolated phase bus ducts

This paper deals with an integral numerical method suitable to predict the current density distribution in typical multiconductor systems represented by gas-insulated lines (GIL) or by isolated phase MV bus ducts, highlighting their proximity effect. Besides the prediction of power density distribution due to Joule losses, the integral approach makes the evaluation of the external flux density easy. The simplicity of the approach, the conciseness of the matrix algebra applied, and the close-to-reality procedure make this method extremely attractive for self-made software implementation on any commercially available math packages such as Matlab. For the sake of comparison, a finite-element method (FEM) model of the system has been implemented. In this model, a coupling between electric circuit and electromagnetic model has been used in order to take into account the real power supply conditions.

Magnetic Field Synthesis in the Design of Inductors for Magnetic Fluid Hyperthermia

A magnetic fluid hyperthermia (MFH) inductor design using multiobjective evolution strategy techniques is proposed. Uniformity of the magnetic field and solution sensitivity are the objective functions chosen for the selection of the inductor geometry. After a 3-D finite-element analysis (FEA) of the thermal field, the coupled-field response of the synthesized inductor has been assessed.

Solution of coupled electromagnetic and thermal problems in gas-insulated transmission lines

Gas-insulated high-voltage and extra high-voltage transmission lines are a new technology for transmitting high-power ratings over long distances. A previous paper was devoted to predict the current distribution along with the external flux density in this multiconductor system, highlighting its proximity effect. It served as the vehicle for the present further research taking into account the thermal problems coupled to the electromagnetic field. The aim of the present paper, therefore, is to show the concordance between literature analytical formulas and the finite-element method (FEM) approach considering the concrete tunnel installations. The FEM model is able to study the precise thermal distribution inside the phase and enclosure thickness both in the steady-state regime and transient condition due to the phase-to-ground short circuit.

Coupled field synthesis in Magnetic Fluid Hyperthermia

In this paper, the actual synthesis of the thermal field is proposed and solved as an inverse problem, considering a fully coupled magnetic-thermal analysis as for the direct problem. Reference is made to an air-cored inductor for magnetic fluid hyperthermia (MFH).

Synthesizing Distributions of Magnetic Nanoparticles for Clinical Hyperthermia

An automated procedure based on evolutionary computation and Finite Element Analysis (FEA) is proposed to synthesize the optimal distribution of nanoparticles (NPs) in multi-site injection for a Magnetic Fluid Hyperthermia (MFH) therapy. In particular a bi-objective formulation of the synthesis problem is considered taking into account both surface and volume temperature distribution in the tumor region.

Electromagnetic and thermal analysis of the induction heating of aluminum billets rotating in DC magnetic field

Purpose – The paper aims to deal with the induction heating of metal billets rotating in a DC magnetic field.Design/methodology/approach – The induced power distributions are analysed and the main heating parameters are estimated with reference to an infinitely long Al billet 200 mm diameter. The paper refers to the activity developed in the frame of a National Italian Project carried out by research groups of the Universities of Bologna, Padua and Roma “La Sapienza.”Findings – The main process parameters have been evaluated for the heating up to 500°C of an Al billet 200 mm diameter.Practical implications – This innovative technology appears to be very promising for improving the efficiency of the through heating of high‐conductivity metals (e.g. copper, aluminum) before hot working, by using superconducting magnets.Originality/value – The paper analyses the induction heating of a infinitely long billet rotating in a uniform DC magnetic field.

A Paretian Approach to Optimal Design With Uncertainties: Application in Induction Heating

A major issue in optimal design of electromagnetic devices relates to optimizing against uncertainty, in terms of geometric and physical parameters. The induction heating of a graphite disk, with the purpose to obtain a prescribed temperature profile, is considered as the model problem. The novelty of this paper is a cost-effective method enabling the designer to select the Pareto optimal solutions trading off design criterion and sensitivity.

Multiphysics modeling of induction hardening of ring gears for the aerospace industry

Induction heating has been widely used for heat treating and especially surface hardening in a broad variety of applications, ranging from the automotive to the renewable energy market. However, the lack of precise knowledge about the interrelation between all the concurrent physical phenomena occurring within the part during the heating cycle has restricted its use to mass-production items (mostly gears). The benefits of this technology, which is clean, repeatable, and cost-effective, could boost its introduction into more conservative industry sectors, such as aerospace, where furnace-based treatments (e.g., carburizing) represent the golden standard. The major limitation is related to the optimization of the induction hardening process, which usually requires significant material know-how and can thus be very long and expensive. Computer simulation could provide a general tool for understanding and improving the critical aspects of each step of the process, thus speeding up the spreading of the induction technology into new markets.

Comparison of edge-effects of transverse flux and travelling wave induction heating inductors

In this paper a comparison of the edge-effects in the induction heating of thin aluminium strips by transverse flux (TF) and travelling wave (TW) inductors at power frequencies is presented. The main attention is focused on the choice of the optimal position of the inductor relative to the strip for both systems in order to minimise the unevenness of power density distribution, both in the workpiece cross section and along the strip movement direction. The calculations of the electromagnetic field quantities have been made by 3D finite element models.