Antonio Carlos Siqueira de Lima | Universidade Federal do Rio de Janeiro (UFRJ) (original) (raw)

Antonio Carlos Siqueira de Lima

Uploads

Papers by Antonio Carlos Siqueira de Lima

Research paper thumbnail of Electro-Osmosis and Heating in HVDC Grounding Systems

Research paper thumbnail of Modeling adjustable-speed drives with long feeders

… , IEEE Transactions on, 2000

This paper presents the modeling of different topologies of electric drive systems when the cable... more This paper presents the modeling of different topologies of electric drive systems when the cable that connects the converter to the motor has a significant length. The long feeder together with converter harmonics decrease the performance of the motor. To correctly assess the voltage and the current throughout the drive system, frequency-dependent models for the cable and the motor should be used. A frequency-dependent cable model is necessary for an accurate voltage evaluation while a frequency-dependent motor model responds for accuracy in the current. The models were validated through experimental results carried out on an actual oil platform and from a prototype system. The latter system was used to test the system's performance when very long motor leads (longer than 5 km) are involved.

Research paper thumbnail of Numerical simulations of flows over a rotating circular cylinder using the immersed boundary method

Journal of the Brazilian …, 2011

In this paper, numerical simulations of incompressible flows around rotating circular cylinders h... more In this paper, numerical simulations of incompressible flows around rotating circular cylinders have been performed. The two-dimensional Navier-Stokes equations are solved by using a Cartesian non-uniform grid. The Immersed Boundary Method (IBM) with the Virtual Physical Model (VPM) was used in order to model the presence of the circular cylinder in the flow. The fractional time step method was used to coupling the pressure and velocity fields. The simulations were carried out for Reynolds numbers equals to 60, 100 and 200 for different specific rotations. The effects of rotation on flow characteristics and fluctuating forces were investigated. The Strouhal number, obtained by performing the Fast Fourier Transform (FFT) of the temporal distribution of the lift coefficient, and the pressure coefficients, were also been calculated. Vorticity contours are presented considering different values of the Reynolds number and specific rotation. The numerical results obtained are compared to those obtained by other authors and the usefulness of the numerical methodology composed by the combination of the IBM with the VPM to simulate flows in the presence of mobile bodies is highlighted.

Research paper thumbnail of Kronecker descriptor partitioning for parallel algorithms

Research paper thumbnail of Modeling adjustable-speed drives with long feeders

IEEE Transactions on Industrial Electronics, 2000

This paper presents the modeling of different topologies of electric drive systems when the cable... more This paper presents the modeling of different topologies of electric drive systems when the cable that connects the converter to the motor has a significant length. The long feeder together with converter harmonics decrease the performance of the motor. To correctly assess the voltage and the current throughout the drive system, frequency-dependent models for the cable and the motor should be used. A frequency-dependent cable model is necessary for an accurate voltage evaluation while a frequency-dependent motor model responds for accuracy in the current. The models were validated through experimental results carried out on an actual oil platform and from a prototype system. The latter system was used to test the system's performance when very long motor leads (longer than 5 km) are involved.

Research paper thumbnail of Electro-Osmosis and Heating in HVDC Grounding Systems

Research paper thumbnail of Modeling adjustable-speed drives with long feeders

… , IEEE Transactions on, 2000

This paper presents the modeling of different topologies of electric drive systems when the cable... more This paper presents the modeling of different topologies of electric drive systems when the cable that connects the converter to the motor has a significant length. The long feeder together with converter harmonics decrease the performance of the motor. To correctly assess the voltage and the current throughout the drive system, frequency-dependent models for the cable and the motor should be used. A frequency-dependent cable model is necessary for an accurate voltage evaluation while a frequency-dependent motor model responds for accuracy in the current. The models were validated through experimental results carried out on an actual oil platform and from a prototype system. The latter system was used to test the system's performance when very long motor leads (longer than 5 km) are involved.

Research paper thumbnail of Numerical simulations of flows over a rotating circular cylinder using the immersed boundary method

Journal of the Brazilian …, 2011

In this paper, numerical simulations of incompressible flows around rotating circular cylinders h... more In this paper, numerical simulations of incompressible flows around rotating circular cylinders have been performed. The two-dimensional Navier-Stokes equations are solved by using a Cartesian non-uniform grid. The Immersed Boundary Method (IBM) with the Virtual Physical Model (VPM) was used in order to model the presence of the circular cylinder in the flow. The fractional time step method was used to coupling the pressure and velocity fields. The simulations were carried out for Reynolds numbers equals to 60, 100 and 200 for different specific rotations. The effects of rotation on flow characteristics and fluctuating forces were investigated. The Strouhal number, obtained by performing the Fast Fourier Transform (FFT) of the temporal distribution of the lift coefficient, and the pressure coefficients, were also been calculated. Vorticity contours are presented considering different values of the Reynolds number and specific rotation. The numerical results obtained are compared to those obtained by other authors and the usefulness of the numerical methodology composed by the combination of the IBM with the VPM to simulate flows in the presence of mobile bodies is highlighted.

Research paper thumbnail of Kronecker descriptor partitioning for parallel algorithms

Research paper thumbnail of Modeling adjustable-speed drives with long feeders

IEEE Transactions on Industrial Electronics, 2000

This paper presents the modeling of different topologies of electric drive systems when the cable... more This paper presents the modeling of different topologies of electric drive systems when the cable that connects the converter to the motor has a significant length. The long feeder together with converter harmonics decrease the performance of the motor. To correctly assess the voltage and the current throughout the drive system, frequency-dependent models for the cable and the motor should be used. A frequency-dependent cable model is necessary for an accurate voltage evaluation while a frequency-dependent motor model responds for accuracy in the current. The models were validated through experimental results carried out on an actual oil platform and from a prototype system. The latter system was used to test the system's performance when very long motor leads (longer than 5 km) are involved.

Log In