Exact Solution of Axial Stress for a Multilayered Pressure Vessel Subjected to Mechanical and Thermal Loads

2012 ◽  
Vol 197 ◽  
pp. 185-189
Author(s):  
Ze Wu Wang ◽  
Qian Zhang ◽  
Liang Zhi Xia ◽  
Da Peng Hu
Keyword(s):  
Exact Solution ◽  
Numerical Solution ◽  
Pressure Vessel ◽  
Thermal Load ◽  
Structural Strength ◽  
Axial Stress ◽  
Urea Synthesis ◽  
Thermal Loads ◽  
Precise Calculation ◽  
Good Agreement

At present, limited work was reported on the exact solution of axial stress for a multilayered pressure vessel subjected to mechanical and thermal loads. However, the axial stress plays an important role to the structural strength due to the influence of thermal load. Based on the theory of thermo-elasticity and finite element (FE) technology, therefore, the exact solution and numerical solution were constructed for a multilayered urea synthesis tower made of different kinds of materials subjected to an internal pressure and a thermal load. Results show good agreement between the theoretical solution and numerical solution, and thus it demonstrates the reliability of the derivation process and developed calculation formula, which would be helpful for more precise calculation and scientific design of the multilayered pressure vessel.

scholarly journals Numerical Solution of the Modified Equal Width Wave Equation

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Seydi Battal Gazi Karakoç ◽  
Turabi Geyikli
Keyword(s):  
Finite Element Method ◽  
Exact Solution ◽  
Finite Element ◽  
Wave Equation ◽  
Numerical Solution ◽  
Wave Motion ◽  
B Spline ◽  
Spline Finite Element ◽  
Method Accuracy ◽  
Good Agreement

Numerical solution of the modified equal width wave equation is obtained by using lumped Galerkin method based on cubic B-spline finite element method. Solitary wave motion and interaction of two solitary waves are studied using the proposed method. Accuracy of the proposed method is discussed by computing the numerical conserved laws and error norms. The numerical results are found in good agreement with exact solution. A linear stability analysis of the scheme is also investigated.

scholarly journals Algebraic Approach to Exact Solution of the (2 + 1)-Dimensional Dirac Oscillator in the Noncommutative Phase Space

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
H. Panahi ◽  
A. Savadi
Keyword(s):  
Exact Solution ◽  
Phase Space ◽  
Algebraic Approach ◽  
Wave Functions ◽  
Dirac Oscillator ◽  
Noncommutative Phase Space ◽  
Energy Eigenvalues ◽  
Good Agreement

We study the (2 + 1)-dimensional Dirac oscillator in the noncommutative phase space and the energy eigenvalues and the corresponding wave functions of the system are obtained through the sl(2) algebraization. It is shown that the results are in good agreement with those obtained previously via a different method.

scholarly journals The method of exact solution of the problem of short-range guidance with two turns

2018 ◽  
pp. 91-99
Author(s):  
A. E. Felikson
Keyword(s):  
Exact Solution ◽  
Numerical Solution ◽  
Iterative Process ◽  
Short Range

The task of determining the guidance parameters by the “two-turn maneuver” method is related to numerical solution of an equation defining the trajectory of the fighter-interceptor. We propose an easy-to-implement in software approach which is based on the exact solution of the problem at each step of the iterative process constructed by one of the parameters

scholarly journals Use of Mini-CT Specimens for Fracture Toughness Characterization of Low Upper-Shelf Linde 80 Weld Before and After Irradiation

2018 ◽  
Author(s):  
Mikhail A. Sokolov
Keyword(s):  
Fracture Toughness ◽  
Pressure Vessel ◽  
Master Curve ◽  
Collaborative Program ◽  
Before And After ◽  
Minimum Number ◽  
Real Practice ◽  
Reactor Pressure ◽  
Good Agreement

Mini-CT specimens are becoming a highly popular geometry for use in reactor pressure vessel (RPV) community for direct measurement of fracture toughness in the transition region using the Master Curve methodology. In the present study, Mini-CT specimens were machined from previously tested Charpy specimens of the Midland low upper-shelf Linde 80 weld in both, unirradiated and irradiated conditions. The irradiated specimens have been characterized as part of a joint ORNL-EPRI-CRIEPI collaborative program. The Linde 80 weld was selected because it has been extensively characterized in the irradiated condition by conventional specimens, and because of the need to validate application of Mini-CT specimens for low upper-shelf materials — a more likely case for some irradiated materials of older generation RPVs. It is shown that the fracture toughness reference temperatures, To, derived from these Mini-CT specimens are in good agreement with To values previously recorded for this material in the unirradiated and irradiated conditions. However, this study indicates that in real practice it is highly advisable to use a much larger number of specimens than the minimum number prescribed in ASTM E1921.

scholarly journals Energy Dependence of Total Cross Sections for Reactions with 4, 6he, 6, 7, 9li Nuclei

KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Yu Penionzhkevich ◽  
Yu Sobolev ◽  
V Samarin ◽  
M Naumenko
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Numerical Solution ◽  
Energy Dependence ◽  
Cross Sections ◽  
Beam Energy ◽  
Microscopic Analysis ◽  
Time Dependent ◽  
Total Cross Sections ◽  
Good Agreement

The paper presents the results of measurement of the total cross sections for reactions 4,6He + Si and 6,7,9Li + Si in the beam energy range 5−50 A⋅MeV. The enhancements of the total cross sections for reaction 6He + Si compared with reaction 4He + Si, and 9Li + Si compared with reactions 6,7Li + Si have been observed. The performed microscopic analysis of total cross sections for reactions 6He + Si and 9Li + Si based on numerical solution of the time-dependent Schrödinger equation for external neutrons of projectile nuclei 6He and 9Li yielded good agreement with experimental data.

Influences of overall thermal balance on local inputs for drive of evaporation in men

1987 ◽  
Vol 62 (3) ◽  
pp. 926-931 ◽  
Author(s):  
M. Heising ◽  
J. Werner
Keyword(s):  
Thermal Load ◽  
Sweat Rate ◽  
Thermal Balance ◽  
Whole Body ◽  
Thermal Loads ◽  
Climatic Chamber ◽  
Local Skin ◽  
Local Skin Temperature ◽  
Local Mean ◽  
Regulatory Models

Three kinds of experiments were carried out in a climatic chamber: experiments with warm load on the whole body at 36 degrees C (4 subjects); experiments at 36 degrees C with reduction of thermal load (28 degrees C) on the left leg (right leg at 36 degrees C) (8 subjects); and experiments at 36 degrees C with antisymmetric thermal load on the legs of 44 degrees C (right leg) and 28 degrees C (left leg), which resulted in additional thermal loads of +/- 30 W/leg (8 subjects). The additional thermal loads, which were applied via two climatic boxes, produced measurable effects on sweat rate when applied to one leg only. In comparison to the experiment 1, experiment 2 brought about a significant reduction of local evaporation on the left leg. With antisymmetric thermal loads on both legs (experiment 3), which did not influence the overall thermal balance, there was no significant influence on local evaporation, although significant changes of local temperatures were measured. It is suggested that the well-known regulatory models, declaring local, mean skin, and core temperatures as local evaporation drive should be supplemented with an important additional feature: local control of evaporation by local skin temperature may be blocked by an overall thermal balance.

Investigation of the Oscillatory Behavior of Electrostatically-Actuated Microbeams

2010 ◽  
Author(s):  
Mahdi Mojahedi ◽  
Mahdi Moghimi Zand ◽  
Mohammad Taghi Ahmadian
Keyword(s):  
Differential Equation ◽  
Homotopy Perturbation Method ◽  
Axial Stress ◽  
Nonlinear Partial Differential Equation ◽  
Nonlinear Ordinary Differential Equation ◽  
Oscillatory Behavior ◽  
Electrostatically Actuated ◽  
Homotopy Analysis ◽  
Analytic Expressions ◽  
Good Agreement

Vibrations of electrostatically-actuated microbeams are investigated. Effects of electrostatic actuation, axial stress and midplane stretching are considered in the model. Galerkin’s decomposition method is utilized to convert the governing nonlinear partial differential equation to a nonlinear ordinary differential equation. Homotopy perturbation method (i.e. a special and simpler case of homotopy analysis method) is utilized to find analytic expressions for natural frequencies of predeformed microbeam. Effects of increasing the voltage, midplane stretching, axial force and higher modes contribution on natural frequency are also studied. The anayltical results are in good agreement with the numerical results in the literature.

scholarly journals A New Algorithm for Solving Terminal Value Problems of q-Difference Equations

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Yong-Hong Fan ◽  
Lin-Lin Wang
Keyword(s):  
Exact Solution ◽  
Numerical Methods ◽  
Error Estimate ◽  
Numerical Solution ◽  
Numerical Method ◽  
Difference Equations ◽  
Initial Value Problems ◽  
Convergence Speed ◽  
Initial Value ◽  
Delta Derivatives

We propose a new algorithm for solving the terminal value problems on a q-difference equations. Through some transformations, the terminal value problems which contain the first- and second-order delta-derivatives have been changed into the corresponding initial value problems; then with the help of the methods developed by Liu and H. Jafari, the numerical solution has been obtained and the error estimate has also been considered for the terminal value problems. Some examples are given to illustrate the accuracy of the numerical methods we proposed. By comparing the exact solution with the numerical solution, we find that the convergence speed of this numerical method is very fast.

Analysis of Flashing and Slow Descending Phenomenon in Ring Coelom of Integrated Reactor During LOCA

2016 ◽  
Author(s):  
Dingqu Wang ◽  
Yan Wang ◽  
Songyang Li ◽  
Haijun Jia ◽  
Lina Jin ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Pressure Vessel ◽  
Liquid Level ◽  
Mitigation Measure ◽  
Coolant Loop ◽  
Good Agreement

Integrated reactor has an integrated pressure vessel with all components of the main coolant loop inside. Ring coelom is formed between the pressure vessel and the heat exchanger. Several small-bore pipes are plugged into the ring coelom to attain the coolant. Because of the existence of the isolated ring coelom, slow descending phenomenon of liquid level in the ring coelom takes place during LOCA with a coolant diversion pipe breaking. The phenomenon is analyzed by modelling the reactor during LOCA in Relap5 and one mitigation measure is acquired. As drastic flashing seriously influences the slow descending phenomenon, which enhance the pressure in the ring coelom, we divide the ring coelom into several parts and use Fluent to gain the flashing details. The results of Relap5 and Fluent show good agreement, which proves the flashing and slow descending phenomenon in the ring coelom of integrated reactor is reasonable during LOCA.

True Stress and Shakedown Analysis of Pressure Vessel which under Cyclic Loading to Plastic Deformation

2014 ◽  
Vol 590 ◽  
pp. 8-12
Author(s):  
Xiao Liang Jia ◽  
Yi Liang Zhang ◽  
Jing Wang ◽  
Chun Bo Wang
Keyword(s):  
Plastic Deformation ◽  
Constitutive Model ◽  
Pressure Vessel ◽  
Axial Stress ◽  
Water Pressure ◽  
True Strain ◽  
Test System ◽  
True Stress ◽  
Plastic Shakedown ◽  
The Relationship

The aim of this study is to discuss the plastic shakedown and true stress of the cyclically loaded pressure vessel. A thin-walled cylinder pressure vessel is made according to actual working state and a water pressure test system is built. The vessel is loaded to different strain levels of plastic deformation first. Then it is loaded cyclically to shakedown state. The relationship between plastic strain and shakedown range is given based on numerous experiments. The constitutive model of the true stress-true strain of the vessel is obtained. The experimental results show that the ratcheting obviously occurred when the vessel is cyclically loaded to plastic deformation. The true stress-strain constitutive model which is presented in this paper can show appropriately the constitutive relation of the vessel when it is under multi-axial stress state. The application of uniaxial shakedown constitutive model has been demonstrated in this study.

Sign in / Sign up

Export Citation Format

Share Document