Adam Skorek

Parallel CFD Analysis of Conjugate Heat Transfer in a Dry Type Transformer

In this paper, we present the conjugate heat transfer analysis in a 167-kVA dry-type transformer using the parallel version of the computational fluid dynamics code Fluent 6.0. The renormalization group kappa-epsiv model is proposed to compute the turbulent aspect of the convective airflow inside the transformer metal tank for Air Natural/Air Natural cooling conditions. An experimental approach was used to assess Joule losses in the low-/high-voltage windings and eddy-current losses in the magnetic core. The resulting mathematical model was solved using 14 compute nodes on a distributed machine.

Analysis of high frequency electromagnetic wave propagation using parallel MIMD computer and cluster system

We present a parallel implementation of an algorithm for the determination of the electromagnetic field in a closed three-dimensional space. A homogenous dielectric and a remote radiation source are taken into consideration for the region under scope. Computations were carried out on the two different systems: a parallel MIMD computer, ALEX AVX2; and a cluster system, a network of PCs with an MPI library and Windows NT system. Analysis of the efficiency for the proposed parallel algorithm was carried out in both cases. Based on the results obtained we discuss the advantages and disadvantages of the use of parallel MIMD computers and cluster systems in numerical computations.

A new concept for finite element simulation of induction heating of steel cylinders

This paper presents an algorithm for finite element simulation induction heating of steel cylinders. Such cylinders have been installed as calender rolls in the Calcoil system for paper plants. This algorithm is used in place of the pre-processor module in EMRC NISA II software. A special pre-processing program has been designed for modelling of a typical section of the cylinder. Computed results are compared to infrared measurements of a laboratory model of a calender roll. And, finally, the possibilities of utilizing and developing the algorithm are discussed.<<ETX>>

Nanoscale Thermal Analysis of Electronic Devices

Heat transfer at nanoscale is of importance for many nanotechnology applications. There are typically two types of problems. One is the management of heat; the other is to manipulate the heat flow and energy conversion. In this paper we review the status and progress of theoretical experimental investigations of thermal transport in nanoelectronics devices. In section 2, we discuss different regimes of nanoscale heat transfer phenomena. In section 3, we present an example including nanoscale phonon hotspots in transistors and finally in section 4, we summarize modeling tools for nanoscale heat transfer, followed by a summary of this paper

Transient thermal stability of the x-ray mask SiC-W under short pulse irradiation

Abstract The transient thermal stability of x-ray mask SiC-W has been numerically studied with special reference to the effect of silicon carbide (SiC) thermal conductivity. This paper presents the transient modeling of an x-ray lithography mask undergoing short x-ray pulses (from a laser plasma or similar source). The computations based on a finite element method are performed for a SiC-W mask under a helium gas environment using powerful analytical capabilities of NISA®. Heat generated in the mask membrane, a tungsten absorber, and helium during x-ray exposure is taken into consideration for the transient thermal stability simulation. Parametric studies are performed to identify the effects of the SiCs thermal conductivity, pulse length, x-ray wavelength and pulses repetition rate. Three thermal conductivity values of SiC were studied: 0.41, 1.9 and 3.5 W/cm °C. The temperature distributions obtained were used as input in order to study the mechanical deformations of the membrane and absorber. A three-dimensional finite element models are developed to analyze the heat transfer mechanisms in the mask and mapping the mask distortions resulting from the short pulse irradiation. Results show that pattern thermal distortion can be minimized if low thermal conductivity of the deposit SiC membrane was obtained.

Parallel Approach to the Nanothermal Numerical Analysis

These paper overviews a numerical parallel approach to the thermal phenomena analysis at the nanoscale level. We are assuming that the effect of a single electron can be important to the thermal phenomena linked to a nano-device. To illustrate this importance, we are considering the single electron transistor and we are defining the governing equation from which is possible to do so. Predicting that the thermal analysis of a nanoscale device takes a lot of computations, we are presenting a plan of use of the parallel computing environment

Parallel analysis of electrothermal phenomena in a dry type distribution

In this paper we describe the steps taken to solve electrothermal problems in distributed configurations. For that purpose, we computed the 3D temperature distribution in a dry type transformer by solving the Poisson equation with source terms specific to the topology under scope, that is, heat generation by Joule losses and eddy currents, as well as natural cooling on the outside of the metal casing. Our approach is based on the assumption that heat transfer in the electrical device is predominantly diffusion. The solver used for this problem is the well-know BICCG (block incomplete Choleski conjugate gradient).

Rating of Pipe-Type Cables With Slow Circulation of Dielectric Fluid

This paper presents a new, rigorous approach to calculation of current ratings in pipe type cables with slow circulation of the fluid. Detailed mathematical analysis is presented for the calculation of the hot-spot fluid temperature as a function of the cable geometry and the fluid inlet temperature. The emphasis is placed on real time applications in which the pipe surface temperature is measured. A numerical example from an actual cable installation is presented. A comparison with the commonly applied method based on Bullers model is offered.

HPC approach to thermal analysis of graphene-based single electron transistor

We present an overview of an approach to the thermal modeling of the grapheme-based nanostructures, and its implementation in high performance computing (HPC) system. As example of graphene-based nanosystem, a single electron transistor (SET) is discussed and the governing equations related to its structure are presented. The proposed approach is based on solution of the many-body Schrödinger equation and on the computation of the thermal conductivity using an HPC environment because of a lot of computations required for an accurate thermal analysis of a SET.

Nanothermal Management in Nanoelectronics Systems

In this paper, we are presenting an approach for electro-thermal management in nanoelectronics devices and systems. We are assuming that at the nanoscale level like at the highest the thermal phenomena are important in the conception of the electronics systems. In addition, an optimal location of the heat sources in nonoscale devices is considered as an important issue. A general strategy for numerical modeling of nanoelectronic system is introduced. Each heat source is approximated by a space, time and temperature dependent function. The presented strategy is generalized on any system containing a number N of nanoelectronic devices.