Thermo-Mechanical Safety Analyses of Preliminary Design Experiments for 238Pu Production

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Christopher J. Hurt ◽  
James D. Freels ◽  
Prashant K. Jain ◽  
G. Ivan Maldonado
Keyword(s):  
High Heat ◽  
Mechanical Analysis ◽  
Fissile Material ◽  
Preliminary Design ◽  
Melting Temperatures ◽  
Safety Margins ◽  
Neptunium Dioxide ◽  
Thermal Simulations ◽  
Fully Coupled ◽  
Design Experiments

Safety analyses at the high flux isotope reactor (HFIR) are required to qualify experiment targets for the production of plutonium-238 (238Pu) from neptunium dioxide/aluminum cermet (NpO2/Al) pellets. High heat generation rates (HGRs) due to fissile material and low melting temperatures require a sophisticated set of steady-state thermal simulations in order to ensure sufficient safety margins. These simulations are achieved in a fully coupled thermo-mechanical analysis using comsolmultiphysics for four different preliminary target designs using an evolving set of pre- and postirradiation data inputs, and subsequently evolving solution scopes, from the unique pellet and target designs. A new comprehensive presentation of these preliminary analyses is given and revisited analyses of the first prototypical target designs are presented to reveal the effectiveness of evolving methods and input data.

Thermomechanical Safety Analyses for a 238Pu Production Target at the HFIR

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Christopher J. Hurt ◽  
James D. Freels ◽  
Prashant K. Jain ◽  
G. Ivan Maldonado
Keyword(s):  
High Heat ◽  
Melting Temperatures ◽  
Safety Margins ◽  
Fission Gas ◽  
Neptunium Dioxide ◽  
Thermal Simulations ◽  
Irradiation Behavior ◽  
Fission Gas Release ◽  
Production Target ◽  
Material Irradiation

Safety analyses at the high flux isotope reactor (HFIR) are required to qualify irradiation of production targets containing neptunium dioxide/aluminum cermet (NpO2/Al) pellets for the production of plutonium-238 (238Pu). High heat generation rates (HGRs) due to a fertile starting material (237Np), low melting temperatures, and previously unstudied material irradiation behavior (i.e., swelling/densification, fission gas release) require a sophisticated set of steady-state thermal simulations in order to ensure sufficient safety margins. Experience gained from previous models for preliminary target designs is incorporated into a more comprehensive production target model designed to qualify a target for three cycles of irradiation and illuminate potential in-reactor behavior of the target.

scholarly journals DESIGNING LEARNING ROTATION USING THE CONTEXT OF BAMBOO WOVEN MOTIF

2020 ◽  
Vol 4 (2) ◽  
pp. 100
Author(s):  
Maryati Maryati ◽  
Rully Charitas Indra Prahmana
Keyword(s):  
Design Research ◽  
Learning Trajectory ◽  
Realistic Mathematics Education ◽  
Preliminary Design ◽  
Realistic Mathematics ◽  
Formal Level ◽  
Three Stages ◽  
Transformation Geometry ◽  
Ninth Grade Students ◽  
Design Experiments

An essential part of learning transformation geometry is rotation. Before learning more about other parts of the transformation geometry topic, such as translation, dilation, and reflection, firstly, students are required to understand well about rotation. However, several students have not been able to understand this subject properly due to the stages of learning in the rotation has not been appropriately arranged. Thus, this study aims to design a student learning trajectory in learning rotation, which develop from informal to formal level through the Indonesian Realistic Mathematics Education (IRME) approach. Furthermore, researchers used a design research method divided into three stages, namely preliminary design, design experiments, and retrospective analysis. This study describes how the bamboo woven motif contributes significantly to 31 ninth-grade students understanding the rotation concept. As a result, the woven bamboo motif's context can stimulate students' understanding of rotation. It is proven based on the strategies and models of students during their learning process which contributes to their fundamental knowledge of rotation.

scholarly journals Thermo-Viscoelastic Modeling of the Aircraft Tire Cornering

2015 ◽  
Vol 1099 ◽  
pp. 80-86 ◽  
Author(s):  
Iulian Rosu ◽  
Lama Elias-Birembaux ◽  
Frederic Lebon
Keyword(s):  
Thermal Evolution ◽  
Numerical Models ◽  
Frictional Heating ◽  
Mechanical Analysis ◽  
High Speeds ◽  
Numerical Studies ◽  
Deformation Dynamics ◽  
Viscoelastic Modeling ◽  
Fully Coupled ◽  
Tread Rubber

Some numerical models are proposed for simulate the aircraft tire behaviour on the ground in critical situations. Fully coupled thermo-mechanical analysis procedures taking into account finite deformation, dynamics and frictional contact are studied; the visco-elasticity properties of the rubber were identified. A good agreement is observed at moderate speed, thus the model is extrapolated to high speeds and seems able to predict results in cases for which it is not possible to obtain realistic experimental data. In order to understand the thermal evolution of tire tread rubber materials during rolling and skidding steps, new experimental and numerical studies were also realized on tire tread rubber. The aim of this approach is to simulate and understand the effect of frictional heating on the tire behaviour.

Preparation of High Heat-Resistant Profile Based on PVC/α-MSAN/ABS Ternary Blends

2013 ◽  
Vol 690-693 ◽  
pp. 1581-1585
Author(s):  
Xing Wang ◽  
Shao Yun Guo ◽  
Fei Hu Yang
Keyword(s):  
High Performance ◽  
Softening Temperature ◽  
High Heat ◽  
Mechanical Analysis ◽  
Ternary Blends ◽  
Heat Resistant ◽  
Styrene Acrylonitrile ◽  
Methyl Styrene ◽  
Pvc Profile ◽  
The Impact

In this paper, ternary blends of PVC mixed with α-methyl styrene-acrylonitrile (α-MSAN) and toughening modifier was prepared, with the aim to obtain a high performance PVC profile with an improved heat resistant temperature, better impact property and good processability. The results of dynamic mechanical analysis (DMA) showed the good miscibility owing to the additional intermolecular interaction between α-hydrogen of PVC and AN of α-MSAN. The glass transition temperature (Tg) and vicat softening temperature (VST) were improved remarkably with introduction of α-MSAN due to excellent heat resistant property of α-MSAN. With regard to mechanical and process properties, the impact strength and dynamic rheological property were evaluated.

A structure-coupled CFD method for time-marching flutter analysis

2004 ◽  
Vol 108 (1086) ◽  
pp. 389-401 ◽  
Author(s):  
N. V. Taylor ◽  
C. B. Allen ◽  
A. Gaitonde ◽  
D. P. Jones
Keyword(s):  
Structural Model ◽  
Aircraft Design ◽  
Shape Preservation ◽  
Test Cases ◽  
Aeroelastic Analysis ◽  
Safety Margins ◽  
Time Marching ◽  
Wing Structure ◽  
Cfd Method ◽  
Fully Coupled

AbstractAeroelastic analysis is a critical area of the aircraft design process, as a good understanding of the dynamic behaviour of the wing structure is essential to safe operation of the vehicle. The inevitable inaccuracies present in the modelling of such phenomena impose mass penalties, as large safety margins are necessitated, which in turn lead to overly stiff designs. In an effort to reduce the uncertainty in analysis methods, fully coupled CFD and structural models are under widespread development. This paper describes the results produced by such a system for a series of test cases based on the AGARD445.6 and MDO wings. Results relating to the latter are of particular interest, as significant variations were found to be produced by the different methodologies used in previous studies, the precise cause of which could not be isolated. In an effort to provide this isolation, a detailed description of the method used is given, including the interpolation scheme between the structural model and the aerodynamic surface, and particular attention is given to the issue of aerofoil shape preservation.

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