Ability of the TRAC-P1A computer program to predict blowdown, refill, and reflood phenomena during Semiscale Mod-1 experiments. [PWR]

A computer analysis of a Semiscale Mod-1 Loss-of-Coolant Experiment (LOCE) was performed using the TRAC-P1A computer program. The main purpose of this analysis was to contribute data for the assessment of the ability of TRAC-P1A to predict blowdown, refill, and reflood phenomena during a postulated Loss-of-Coolant Accident (LOCA). A TRAC-P1A Semiscale Mod-1 system model was created and TRAC-P1A was used to obtain initial conditions for Semiscale Mod-1 LOCE S-04-6. After this initialization, TRAC-P1A was used to simulate the first 60 seconds of this experiment. The results of this simulation are presented and discussed

Multidimensional analysis based on a two-fluid model of fluid flow in a component of the LOFT system during a loss of coolant experiment

A computer analysis of fluid flow in the Loss-of-Fluid Test (LOFT) cold leg blowdown pipe during a Loss-of-Coolant Experiment (LOCE) was performed using the computer program K-FIX/MOD1. This analysis constitutes the first application of a two-fluid model to fluid flow in a component of the LOFT system. The purpose of this analysis was to evaluate the capability of K-FIX/MOD1 to obtain theoretical fluid quantity distributions in the blowdown pipe during a LOCE for possible application to the analysis of LOFT experimental data, the determination of mass flow, or the development of data reduction models. A rectangular section of a portion of the blowdown pipe containing measurement Station BL-1 was modeled with fluid inflow from the upper annulus and fluid outflow from this portion of the blowdown pipe represented by time-dependent boundary conditions. Fluid quantities were calculated during a simulation of the first 26 seconds of LOCE L1-4

From fractal media to continuum mechanics

This paper presents an overview of modeling fractal media by continuum mechanics using the method of dimensional regularization. The basis of this method is to express the balance laws for fractal media in terms of fractional integrals and, then, convert them to integer-order integrals in conventional (Euclidean) space. Following an account of this method, we develop balance laws of fractal media (continuity, linear and angular momenta, energy, and second law) and discuss wave equations in several settings (1d and 3d wave motions, fractal Timoshenko beam, and elastodynamics under finite strains). We then discuss extremum and variational principles, fracture mechanics, and equations of turbulent flow in fractal media. In all the cases, the derived equations for fractal media depend explicitly on fractal dimensions and reduce to conventional forms for continuous media with Euclidean geometries upon setting the dimensions to integers. We also point out relations and potential extensions of dimensional regularization to other models of microscopically heterogeneous physical systems

Impact damage assessment by using peridynamic theory

This study presents an application of peridynamic theory for predicting residual strength of impact damaged building components by considering a reinforced panel subjected to multiple load paths. The validity of the approach is established first by simulating a controlled experiment resulting in mixed-mode fracture of concrete. The agreement between the PD prediction and the experimentally observed behavior is remarkable especially considering the simple material model used for the concrete. Subsequently, the PD simulation concerns damage assessment and residual strength of a reinforced panel under compression after impact due to a rigid penetrator