Bertrand Nogarede

The electromagnetic actuator design problem: a general and rational approach

This paper clearly delineates the problem of the design of electromagnetic actuators and presents it as an inverse problem. It discusses optimal formulations and explains the most general and rational way to solve this inverse problem. The methodology is based on the association of an exact interval global optimization algorithm and a new, more general analytical model that represents the structure and the composition of the actuators as well as their dimensions. The methodology can be considered both general and rational. The paper concludes with some practical examples of design that validate the approach.

Analytical modeling for the design of a piezoelectric rotating-mode motor

This paper deals with the analytical modeling of a rotating-mode motor. The modeling, based on an equivalent electric circuit, is established by using geometrical and electromechanical parameters for the different parts of the motor. It gives electromechanical characteristics and other useful values for motor design. Numerical simulations and measurements from a real transducer validate the analysis.

Optimal Design of Multi-Airgap Electrical Machines: An Unknown Size Mixed-Constrained Global Optimization Formulation

This paper solves, in a rational way, more sophisticated electrical machine design problems by extending the work done by Fitan et al. It addresses the special case of multi-airgap cylindrical concentric machines. The solution requires a reformulation of the inverse problem associated with the design of electrical machines. Thus, a new mixed-constrained global optimization problem has to be solved. From a mathematical point of view, a major difficulty is that the number of variables and constraints varies during the resolution, depending on the number of considered airgaps. Moreover, this involves extensions of analytical models used for permanent-magnet machines. The paper uses numerical tests for concentric rotor machines with one, two, and three (in one case) mechanical airgaps to validate this methodology of design

Optimal Design of Piezoelectric Transformers: A Rational Approach Based on an Analytical Model and a Deterministic Global Optimization

This paper deals with a deterministic and rational way to design piezoelectric transformers in radial mode. The proposed approach is based on the study of the inverse problem of design and on its reformulation as a mixed constrained global optimization problem. The methodology relies on the association of the analytical models for describing the corresponding optimization problem and on an exact global optimization software, named IBBA and developed by the second author to solve it. Numerical experiments are presented and compared in order to validate the proposed approach.

A novel concept of pulsatile magnetoactive pump for medical circulatory support

The present contribution deals with the development of a new concept of pulsatile magneto-activated pump devoted to mechanical circulatory support. On the bases of theoretical results, a functional demonstrator has been designed and built at the laboratory. Tests of this demonstrator are detailed showing the flow/pressure characteristics.

Electromagnetic analytical modelling of permanent magnets machine in view of their optimal design

This article present a modelling method well adapted to the study of brushless permanent magnet machines used in high speed drives. The issue of the proposed technique lies on the possibility of taking into account the induced currents flowing in the conductive parts of the machine. This modelling integrates different type of rotor and stator current density. So the basic principles and the validation of this method were given in this paper.

Strong formulation using FDS, weak formulation using FEM and experimental data

In this paper, the authors compare the numerical results obtained from a strong formulation using finite difference schemes (FDS) and a weak formulation using finite element method (FEM). The main purpose of our study is to know which method computes accurately the distribution of magnetic field in an experimental device. Numerical results are compared with a set of experimental data.

Educational bench: self-controlled synchronous machine

This article deals with the presentation of an experimental bench dedicated to the teaching of electromechanical systems during undergraduate curriculum. This bench permits to explain the main principles of an elementary synchronous motor by a practical approach of the physical phenomena. At first, students start to describe theoretically the motor based on the fundamental electromagnetic relations and concretise their calculations by a progressive realization of their coil windings and finally the electromechanical characterization of the motor. The educational approach is done in order to bring students to face with essential questions about machines and electrical drives.

Feasibility investigations on an antithrombotic electroactive function for medical applications

Mechanical circulatory support, as well as cardiopulmonary bypass, requires the blood to interface with an artificial surface. This interaction activates the blood, which in turn tends to form clots. Some geometry, such as the junctions, can facilitate blood coagulation. Fluid dynamic simulations show areas where velocity tends to zero after a bifurcation. The proposed contribution deals with the development of electroactive actuator to avoid the clot formation in a circuit while bringing vibrations on the system in a local area.