Morgana de Vasconcellos Araújo

Transient Heat Transfer in a Packed-Bed Elliptic Cylindrical Reactor: A Finite-Volume Approach

This work aims to develop a transient three-dimensional mathematical model using the elliptic cylindrical coordinate system, to predict heat transfer in a elliptic cylindrical packed fixed bed reactor. The model considers variable thermo physical properties and a parabolic temperature profile at the fluid inlet. The governing equation is solved using the finite volume method. Results of temperature profile along the reactor are presented and discussed at different moments.It was verified that the maximum heat transfer rate inside the reactor occurs near the extreme region close to minor semi-axis of the ellipse; the higher temperatures at the reactor surface are also in this region, along the entire height of the bed; the steady-state regime is reached at t = 4.5 s of process, presenting after this time interval,small axial temperature gradients and high radial gradients along of the reactor bed; the parabolic temperature profile give to the bed a predominance of radial temperature gradients, and the radial porosity profile favours a higher heat transfer rate at reactor surface.

Drying of Industrial Hollow Ceramic Brick: Analysis of the Moisture Content and Temperature Parameters

The study of ceramic drying is theme of several researches today. In most case, this research is realized experimentally, making possible measurements errors that reverberating in data slightly out of the expected, or erroneous. Numerical simulation emerges like a tool that allows the reproduction of experiments using computers and suitable software’s. The use of numerical simulation enables fast changes in boundary conditions and help in the improvement of an unit operation. This paper aims to predict the drying process of an industrial hollow ceramic brick using the liquid diffusion model to describe the behavior of the temperature and moisture content inside the brick and drying kinetics along time, with the help of the Ansys® CFX commercial package. Predicted results of the average moisture content and temperature of the brick were compared with experimental results, and good agreements were obtained. It was verified that regions with smaller thickness dry and heat faster than the others.

Hydrodynamic Study of Oil Leakage in Pipeline via CFD

This paper describes the transient dynamics behavior of oil flow in a pipe with the presence of one or two leaks through fluid dynamics simulations using the Ansys CFX commercial software. The pipe...This paper describes the transient dynamics behavior of oil flow in a pipe with the presence of one or two leaks through fluid dynamics simulations using the Ansys CFX commercial software. The pipe section is three-dimensional with a pipe length of 10 m, a pipe diameter of 20 cm, and leak diameter of 1.6 mm. The interest of this work is to evaluate the influence of the flow velocity, and the number and position of leaks on the transient pressure behavior. These new data may provide support for more efficient detection systems. Thus, this work intends to contribute to the development of tools of operations in oil and gas industry.

On the Use of CFD in Thermal Analysis of Industrial Hollow Ceramic Brick

The manufacture of clay bricks goes through several phases, among which are clay wetting, molding, drying and firing. The drying process has a high energy consumption and the material needs to be dried with control for avoid it to be unusable after drying. Optimization of the drying process (reduction of process time and energy expenditure) is crucial for the ceramist industry. In this sense, this work aims to make a transient thermal study of the temperature distribution in an industrial brick due to the energy supply of drying-air flowing inner it turbulent regime. The study is performed through numerical simulation using the software ANSYS® CFX. Transient results are displayed in terms of fields of the temperature and air velocity, and temperature of the brick. It was concluded that the higher the velocity of flow of hot air, the faster the heat diffuses into the brick. Independent of air velocity, there are temperature gradients on the surface of the brick