Search results for "Casting"

Automatic Secondary Cooling Control for the Continuous Casting Process of Steel

1991

Two simulation models for finding the optimal secondary cooling strategy in continuous casting process are presented. The first one is a two-dimensional off-line model for optimizing steady state casting operation. The second one is a one-dimensional model which can be used for simulating casting operation in real-time during varying casting conditions.

FE-Modelling of Continuous Casting Problem

1986

A mathematical model for simulating the heat transfer during solidification in continuous casting of steel is presented. The heat transfer coefficients along and across the strand are optimized. The evolution and location of thermal stresses are computed. Numerical examples are included.

Nonsmooth Penalty Techniques in Control of the Continuous Casting Process

1991

We introduce a mathematical model which is used to simulate the continuous casting process and to control the secondary cooling water sprays. The main object is to minimize the defects in the final products. The problem is formulated as an optimal control problem where the cost function is constructed according to certain metallurgical criteria and constraints. The temperature distribution of the strand is calculated by solving a nonlinear heat equation with free boundaries between solid and liquid phases.

On Fixed Point (Trial) Methods for Free Boundary Problems

1992

In this note we consider the trial methods for solving steady state free boundary problems. For two test examples (electrochemical machining and continuous casting) we discuss the convergence of a fixed point method. Moreover, using the techniques of shape optimization we introduce a modification of the method, which gives us superlinear convergence rate. This is also confirmed numerically.

On numerical simulation of the continuous casting process

1988

In this paper a steady-state nonlinear parabolic-type model, which simulates the multiphase heat transfer during solidification in continuous casting, is presented. An enthalpy formulation is used and we apply a FE-method in space and an implicit Euler method in time. A detailed solution algorithm is presented. We compute the temperature distributions in the strand when the boundary conditions (mold/spray cooling) on the strand surface are known. The numerical model gives thereby a good basis for the testing of new designs of continuous-casting machines. An application of the model to continuous casting of billets is presented.

A Short-Term Data Based Water Consumption Prediction Approach

2019

A smart water network consists of a large number of devices that measure a wide range of parameters present in distribution networks in an automatic and continuous way. Among these data, you can find the flow, pressure, or totalizer measurements that, when processed with appropriate algorithms, allow for leakage detection at an early stage. These algorithms are mainly based on water demand forecasting. Different approaches for the prediction of water demand are available in the literature. Although they present successful results at different levels, they have two main drawbacks: the inclusion of several seasonalities is quite cumbersome, and the fitting horizons are not very large. With th…

Sea breeze thunderstorms in the eastern Iberian Peninsula. Neighborhood verification of HIRLAM and HARMONIE precipitation forecasts

2014

In this study we investigated sea breeze thunderstorms with intense convective activity (i.e., heavy rainfall, hail and gusty winds) that occurred over the eastern Iberian Peninsula (Spain) and were missed by the operational HIRLAM model. We used two grid-spacing setups (5.0. km and 2.5. km) of the hydrostatic HIRLAM model, and the non-hydrostatic spectral HARMONIE suite (2.5. km), to simulate isolated convection associated with sea breezes. The overall aim is to estimate the ability of these three experimental setups, in particular the HARMONIE model as the forthcoming operational numerical weather prediction in most European Weather Services, to correctly simulate convective precipitation…

Multi-model simulations of a convective situation in low-mountain terrain in central Europe

2008

The goal of the present study is to investigate the variability of simulated convective precipitation by three convection-resolving models using different set-ups and initial and boundary conditions. The COSMO, MM5 and WRF models have been used to simulate the atmospheric situation on 12 July 2006, when local convection occurred in central Europe under weak synoptic forcing. The focus of this investigation is on the convective precipitation in the northern Black Forest in South-West Germany. The precipitation fields from the nine model simulations differ considerably. Six simulations capture the convective character of the event. However, they differ considerably in the location and timing …

The future of transmission electron microscopy (TEM) in biology and medicine.

2000

Tourism recovery amid COVID-19: The case of Lombardy, Italy

2021

Travel restrictions and social distancing imposed to curb the spread of the new coronavirus have been strongly hitting tourism since March 2020. Tourism forecasting literature addressed the effects of shocks in contexts characterized by a predictable route to recovery. COVID-19 is without precedents. In this article, monthly overnight stays for the period January 2010 to December 2020 are used to estimate the impact of the pandemic in Lombardy, Italy’s most affected region. A model-based approach is implemented, and the number of overnight stays up to December 2023 is forecasted. Four models are compared. Estimation results from an augmented SARIMA model suggest that, provided a new lockdo…