Implementation of Fast Searching Method for the Cross-Section Usage in HTGR Simulators

2017 ◽  
Author(s):  
Benjamin Auve ◽  
Chunlin Wei ◽  
Zhe Sui ◽  
Jun Sun
Keyword(s):  
Real Time ◽  
Cross Section ◽  
Cross Sections ◽  
Full Range ◽  
Target Position ◽  
Design Parameters ◽  
Target Point ◽  
Dimension Space ◽  
Searching Method ◽  
Fast Searching

The modular High-Temperature Gas-cooled Reactor (HTGR) is one of the six generation IV advanced nuclear reactors. With the final purpose of operator training and licensing, the engineering simulation system (ESS) has been studied to model the pebble-bed type reactor core and has been successfully implemented into the full scope simulator of HTR-PM. As stated in corresponding industrial standards, one important feature of the nuclear power plant simulator is real-time calculation, and the other one is simulation results with high fidelity (compared to design parameters or operational data in different stages). In ESS, each macro cross-section was in the form of polynomial by function of several variables (like burn-up, buckling, temperatures), the expression of which was finalized by multivariate regression analysis from large scattered database generated by the VSOP. Since the polynomial is explicit and prepared in advance, the macro cross-sections are quickly calculated in running ESS. However, some variables (such as temperature) in HTGR are in larger scope so that the polynomial is not easy to meet full range accuracy. One normal idea is to optimize the expression of polynomial, while another means was proposed and tested in present paper. Other than focusing on the polynomials, a new method, called the fast searching, was described to significantly improve the accuracy of macro cross-section calculation while it was also fast to maintain the real-time feature. Instead of setting up a regression polynomial from the large cross-section database, the fast searching method treated the database as scatted points in the multi-dimension space, and aimed to locate the target position of unknown macro cross-section by fast searching and interpolating. Searching was to find the neighbouring database points around the target point in the multi-dimension space, which naturally improved the accuracy. While interpolating was to predict the macro cross-section of target point based on those neighbouring database points. To keep the searching and interpolating fast, the original database of macro cross-sections was analysed. A series of searching and interpolating methods have been described, programmed, tested and compared to find appropriate methods to calculate all the macro cross-sections in limited time cost. Finally, the fast searching method and its program was implemented into ESS to show better performances.

scholarly journals RESEARCH ON THE CROSS-SECTION GENERATING METHOD IN HTGR SIMULATOR BASED ON MACHINE LEARNING METHODS

2021 ◽  
Vol 247 ◽  
pp. 02039
Author(s):  
LI Zeguang ◽  
Jun Sun ◽  
Chunlin Wei ◽  
Zhe Sui ◽  
Xiaoye Qian
Keyword(s):  
Machine Learning ◽  
Power Plant ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Power ◽  
Full Range ◽  
Neuron Networks ◽  
Machine Learning Methods ◽  
Generating Method ◽  
The Cross

With the increasing needs of accurate simulation, the 3-D diffusion reactor physics module has been implemented in HTGR’s engineering simulator to give better neutron dynamics results instead of point kinetics model used in previous nuclear power plant simulators. As the requirement of real-time calculation of nuclear power plant simulator, the cross-sections used in 3-D diffusion module must be calculated very efficiently. Normally, each cross-section in simulator is calculated in the form of polynomial by function of several concerned variables, the expression of which was finalized by multivariate regression from large number scattered database generated by previous calculation. Since the polynomial is explicit and prepared in advance, the cross-sections could be calculated quickly enough in running simulator and achieve acceptable accuracy especially in LWR simulations. However, some of concerned variables in HTGR are in large scope and also the relationships of these variables are non-linear and very complex, it is very hard to use polynomial to meet full range accuracy. In this paper, a cross-section generating method used in HTGR simulator is proposed, which is based on machine learning methods, especially deep neuron network and tree regression methods. This method first uses deep neuron networks to consider the nonlinear relationships between different variables and then uses a tree regression to achieve accurate cross-section results in full range, the parameters of deep neuron networks and tree regression are learned automatically from the scattered database generated by VSOP. With the numerical tests, the proposed cross-section generating method could get more accurate cross-section results and the calculation time is acceptable by the simulator.

scholarly journals Inductance gradient and current density distribution for T-shaped convex and concave rail cross-sections

2018 ◽  
Vol 7 (1.8) ◽  
pp. 237
Author(s):  
M. N. Saravana Kumar ◽  
R. Murugan ◽  
Poorani Shivkumar
Keyword(s):  
Density Distribution ◽  
Cross Section ◽  
Cross Sections ◽  
Current Density ◽  
Current Density Distribution ◽  
Design Parameters ◽  
Element Analysis ◽  
Analysis Technique ◽  
Section Shape ◽  
Uniform Current

Rectangular rail was the most widely used cross section shape for the rail gun electromagnetic launching (EML) system. Based on sector assimilation, the rail gun key parameter especially current density (J) and inductance gradient (L’) greatly affected. J decides the efficiency of EML and L’ decides the force acting on the projectile of EML. So, it is mandatory to look upon the sector assimilation of rails. In this paper T shape convex and concave shape rail cross section is proposed and rail gun key design parameters are calculated by varying its dimensions using Ansoft Maxwell 2-D eddy current solver which uses finite element analysis technique to calculate these parameters. The performance of rail gun discussed using the obtained values and it has been observed and that the compared with other considered rail geometries, the T-shaped concave model shows more impact on inductance value which causes uniform current density distribution over the rails.

Design of C-Frames Using Real-Coded Genetic Optimization Algorithms and NURBS

1999 ◽  
Author(s):  
Ashraf O. Nassef ◽  
Hesham A. Hegazi ◽  
Sayed M. Metwalli
Keyword(s):  
Genetic Algorithms ◽  
Cross Section ◽  
Cross Sections ◽  
Design Parameters ◽  
Binary Representation ◽  
Cross Sectional ◽  
Search Spaces ◽  
The Cross ◽  
Sectional Shape ◽  
Real Coded Genetic Algorithms

Abstract C-frames constitute a large portion of machine tools that are currently used in industry. Examples of these frames include drilling machines, presses, punching and stamping machines, clamps, hooks, etc. The design parameters of these frames include the dimensions of their cross-sections, which should be chosen to withstand the applied loads and minimize the element’s overall weight. Traditionally, the cross-section of C-frame belonged to a set of primitive shapes, which included I, T, trapezoidal and rectangular sections. This paper introduces a new methodology for designing the frame’s cross-section. The cross-sectional shape is represented using non-uniform rational B-Spline (NURBS) in order to give it a form of shape flexibility. A special form of genetic algorithms known as real-coded genetic algorithms is used to conduct the search for the design objectives. Real-coded genetic algorithms are known to outperform the simple binary representation genetic algorithms when dealing with continuous search spaces. The results showed that the optimal shape was a semi I/T-section with the material bulk related to the applied load.

Design and Numerical Simulation of Radial Inflow Turbine Volute

2014 ◽  
Vol 31 (4) ◽  
Author(s):  
Samip P. Shah ◽  
S.A. Channiwala ◽  
D.B. Kulshreshtha ◽  
Gaurang Chaudhari
Keyword(s):  
Compressible Flow ◽  
Cross Section ◽  
Cross Sections ◽  
Numerical Models ◽  
Circular Cross Section ◽  
Design Procedure ◽  
Design Parameters ◽  
Flow Angle ◽  
Trapezoidal Cross Section ◽  
Radial Inflow Turbine

AbstractThe volute of a radial inflow turbine has to be designed to ensure that the desired rotor inlet conditions like absolute Mach number, flow angle etc. are attained. For the reasonable performance of vaneless volute turbine care has to be taken for reduction in losses at an appropriate flow angle at the rotor inlet, in the direction of volute, whose function is to convert gas energy into kinetic energy and direct the flow towards the rotor inlet at an appropriate flow angle with reduced losses. In literature it was found that the incompressible approaches failed to provide free vortex and uniform flow at rotor inlet for compressible flow regimes. So, this paper describes a non-dimensional design procedure for a vaneless turbine volute for compressible flow regime and investigates design parameters, such as the distribution of area ratio and radius ratio as a function of azimuth angle. The nondimensional design is converted in dimensional form for three different volute cross sections. A commercial computational fluid dynamics code is used to develop numerical models of three different volute cross sections. From the numerical models, losses generation in the different volutes are identified and compared. The maximum pressure loss coefficient for Trapezoidal cross section is 0.1075, for Bezier-trapezoidal cross section is 0.0677 and for circular cross section is 0.0438 near tongue region, which suggested that the circular cross section will give a better efficiency than other types of volute cross sections.

scholarly journals Neutronics of Lead and Bismuth

2021 ◽  
pp. 177-213
Author(s):  
Cheol Ho Pyeon
Keyword(s):  
Numerical Simulations ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Data ◽  
Design Parameters ◽  
Integral Parameter ◽  
Considerable Impact ◽  
Test Materials ◽  
Design Calculations ◽  
Data Libraries

AbstractCross-section uncertainties of Pb and Bi isotopes could consequently affect the precision of nuclear design calculations of preliminary analyses, before the actual operation of upcoming ADS, since Pb and Bi are composed partly of coolant material (lead-bismuth eutectic: LBE) in ADS facilities. The main characteristics of LBE in ADS are recognized as follows: chemically inactive; high boiling point mechanically; excellent neutron economy caused by large scattering cross sections. From the viewpoint of neutronics, LBE exerts considerable impact on nuclear design parameters for numerical simulations of neutron interactions of Pb and Bi isotopes. As a suitable way of investigating cross-section uncertainties, sample reactivity worth measurements in critical states are considered effective with the use of reference and test materials in a zero-power state, such as a critical assembly, because integral parameter information on cross sections of test materials can be acquired experimentally. For the required experimental study on Pb and Bi nuclear data uncertainties, the sample reactivity worth experiments are carried out at the KUCA core by the substitution of reference (aluminum) for test (Pb or Bi) materials, and numerical simulations are performed with stochastic and deterministic calculation codes together with major nuclear data libraries.

Numerical Investigation and Optimization of Shape and Design Parameters of Lift Rod of Helicopter

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
R. Saravanan ◽  
T. Gopalakrishnan
Keyword(s):  
Numerical Investigation ◽  
Failure Mode ◽  
Cross Section ◽  
Cross Sections ◽  
Mode Analysis ◽  
Design Parameters ◽  
Force System ◽  
Good Design ◽  
Failure Mode Analysis ◽  
Functional Components

The technological advantages lead to design the components and systems of great extent. The functional components and their dimensions are to be designed well for ensuring safe and reliable operations. The lift rod of helicopter is considered here for optimization. The failure mode analysis results show that the lift rod fails often and found to have less life period because of some complex force system that is encountered while landing, take-off and continuation of flight. Initially the existing design parameters and cross sections were considered as it is for observation. Based on the observation, the cross section was optimized to some extent. Then the design parameters are increased to 3 levels. The lift rod is analysed again with modified parameters. Finally, both the dimensions and shape are optimized to achieve a good design with desirable characteristics.

scholarly journals Free Vibration of Composite Thin-Walled Beams with Chordwise Asymmetric Closed Cross-Sections

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Keun-Taek Kim
Keyword(s):  
Free Vibration ◽  
Galerkin Method ◽  
Cross Section ◽  
Cross Sections ◽  
Transverse Shear ◽  
Composite Beam ◽  
Vibration Characteristics ◽  
Design Parameters ◽  
Anisotropic Composite ◽  
Thin Walled

In this paper, some analytical results via extended Galerkin method on free vibration characteristics of an anisotropic composite beam, which is modeled as a nonuniform thin-walled structure with a chordwise asymmetric closed cross-section and corrected the warping functions, are newly presented. For this study, nonclassical parameters such as warping restraint, transverse shear flexibility, and structural couplings induced by two special configurations, such as circumferentially uniform stiffness (CUS) and circumferentially asymmetric stiffness (CAS), are incorporated. And also, design parameters of the beam associated with preset angles, pretwist angles, taper ratios, and section ratios are additionally investigated. The results of this study could play an important role in more efficient designs of composite thin-walled beams.

Investigation of the Influence of the Bourdon Effect on the Stress and Ovalization in Elbows

2014 ◽  
Author(s):  
Farzad M. Shemirani ◽  
Samer Adeeb ◽  
J. J. Roger Cheng ◽  
Michael Martens
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Maximum Stress ◽  
Oil And Gas ◽  
Design Parameters ◽  
Operating Pressure ◽  
Actual Situation ◽  
Straight Pipe ◽  
Element Analysis ◽  
Pipe Length

Elbows are used frequently in pipeline systems. Manufacturing of elbows tends to cause the primary circular sections to ovalize. Ovalization intensifies when elbows are subjected to internal hoop pressure. The total ovality in elbows comprises both manufacturing and pressurization ovality. Elbows with oval cross sections under internal pressure tend to straighten. This effect is called the Bourdon Effect. If these effects are not taken into consideration, unanticipated deformations and higher stress levels could be present at the location of elbows. The Canadian oil and gas pipeline code (CSA Z662-11) has limited the ovality in elbows to 3 and 6 percent for progressive and non-progressive ovalizations, respectively. A mere imposition of two limits cannot determine the safety factor of pipeline. Also, consequences of using elbows with large ovality remain ambiguous as well. Understanding the influence of the Bourdon Effect and ovalization on the elbow design parameters is required. In this paper, the influence of the Bourdon Effect on the stress and ovalization developed in the elbows are investigated. Four Nominal Pipe Sizes (12, 24, 36, and 42) are selected. Elbows and straight pipe segments connected to them are analyzed using Finite Element Analysis. Geometric dimensions of actual scanned pipeline elbows are used to represent the actual situation in the field. Under the operating pressure, the maximum stress, ovality, and the Bourdon Effect in elbows for different elbow thicknesses and straight pipe lengths connected to the elbows are monitored. In addition, in this paper, the effect of the initial ovality was investigated for NPS 24 with constant straight pipe length. It was shown that the increase or decrease in the final ovality of the pipe is dependent on the initial ovality of the elbow cross section.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

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