scholarly journals An Inviscid Low-Solidity Cascade Design Routine

1993 ◽  
Author(s):  
Jerry G. Myers ◽  
Terry Wright
Keyword(s):  
Experimental Data ◽  
Accurate Method ◽  
Analysis Procedure ◽  
Suitable Method ◽  
Design System ◽  
Design Technique ◽  
Axial Fan ◽  
Design Information ◽  
Design Values

An investigation was performed to determine a suitable method of designing and analyzing the performance of straight axial fan cascades of solidities below 0.6. The methods investigated included direct interpolation between design values obtained from experimental data at solidities of 0.6 and isolated airfoil theory predictions. A new inviscid design technique developed from a simplified low-solidity analysis procedure by J. Horlock and K. Tanabe was also developed. Testing of these methods was performed using a PC based inviscid “panel” routine developed by McFarland at NASA-Lewis. Results of the investigation yielded a reasonably accurate method for the design of axial fan cascades for solidities ranging from 0.2 to 0.6 which can supplement an existing design system that requires cascade design information lying beyond the range of NACA testing.

Implosion Analysis of Concrete Cylindrical Vessels

1979 ◽  
Vol 101 (1) ◽  
pp. 98-102
Author(s):  
H. Suzuki ◽  
W. F. Chen ◽  
T. Y. Chang
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Fracture Behavior ◽  
Constitutive Relations ◽  
Analysis Procedure ◽  
Material Behavior ◽  
Ultimate State ◽  
Element Analysis ◽  
Proposed Model ◽  
Effect Of Hydrostatic Pressure

Concrete constitutive relations which can simulate the overall material behavior up to and including its ultimate state under general triaxial loading conditions have been developed. The proposed constitutive relations include: 1) plastic deformation considering the effect of hydrostatic pressure, 2) a dual criterion predicting the fracture of concrete in terms of either stresses or strains, and 3) post-fracture behavior of concrete. Corresponding to the constitutive model, a finite element analysis procedure has also been utilized. Based on the proposed model, implosion pressures and load-deformation responses of several concrete vessels were obtained. The numerical results correlate quite well with the experimental data when the dual criterion was used.

Development of a Reference Enterprise Model for Fixture Design Information Support in Integrated Manufacturing

Manufacturing ◽  
2003 ◽  
Author(s):  
Fathianathan Mervyn ◽  
A. Senthil Kumar ◽  
Bok Shung Hwee ◽  
Andrew Nee Yeh Ching
Keyword(s):  
Information Exchange ◽  
Manufacturing Systems ◽  
Reference Model ◽  
Information Support ◽  
Design System ◽  
Fixture Design ◽  
Integrated Manufacturing ◽  
Design Information ◽  
Computer Aided ◽  
Machining Fixtures

A crucial factor in the success of developing integrated manufacturing systems lies in the ability to exchange information among the various computer-aided systems. Although a vast amount of research has been conducted on computer-aided fixture design systems, the need for information exchange between a fixture design system and other manufacturing systems has not been dealt with thoroughly. Models for the exchange of information within an enterprise or within an extended enterprise depend on the functionality and behaviour of individual enterprises. One means of developing an information model for an enterprise is to determine the information requirements by modelling the enterprise. However, this results in a monolithic model that is only applicable to that enterprise. As a solution to this drawback, we describe the development of a reference model for fixture design information support, which can be instantiated to be applied to different types of enterprises. We concentrate on machining fixtures and information form the fixture design domain to other domains.

Studies on Onset of Ratcheting in Pipe Bends and Effect of Thickness on Strain Accumulation

2005 ◽  
Author(s):  
K. Shanmuga Sundaram ◽  
G. Thanigaiyarasu ◽  
Manoj Kumar Palaniswamy
Keyword(s):  
Experimental Data ◽  
Analytical Study ◽  
Material Model ◽  
Analysis Procedure ◽  
Strain Accumulation ◽  
Research Papers ◽  
Non Linear ◽  
Different Thickness

This paper intends to provide an overview of various possibilities of ratcheting in pipelines subjected to cyclic thermal and mechanical loadings. The present work deals with review on results from the studies of research papers providing experimental data and analytical study on ratcheting. There has been no well-defined material model and analysis procedure to predict this phenomenon accurately. An analysis carried out on 2-inch NPS SS304 pipe bends with different thickness (Schedule 40 and Schedule 80) using ABAQUS, non-linear FEA software to predict the strain accumulation and their influences on ratcheting failure is presented. The results and their inferences are included.

scholarly journals Modeling heat transfer process in soils

2018 ◽  
Vol 251 ◽  
pp. 02048 ◽  
Author(s):  
Ian Ofrikhter ◽  
Alexander Zaharov ◽  
Andrey Ponomaryov ◽  
Natalia Likhacheva
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
Analytical Calculation ◽  
Accurate Method ◽  
Heat Transfer Process ◽  
Preliminary Evaluation ◽  
Soil Base ◽  
Undisturbed Sample ◽  
Analytical Formulas

In this paper, a new model is presented for calculating the thermal conductivity of soils, and the main provisions for the derivation of analytical formulas are given. The presented model allows taking into account the density, moisture content and temperature of the soil base. The technique presented in the paper makes it possible to dispense with laborious experiments to estimate the thermal conductivity of the soil. The method of analytical calculation is step by step presented in the paper. Two variants of using the method are proposed: 1) Less accurate method, for preliminary evaluation, without the need to take probe and conduct experiments. 2) More accurate method, with at least one experiment with a disturbed or undisturbed sample. The results of comparison of calculated values of thermal conductivity and experimental data are presented.

Numerical analysis of seismically induced liquefaction in earth embankment foundations. Part I. Benchmark model

2003 ◽  
Vol 40 (4) ◽  
pp. 753-765 ◽  
Author(s):  
Ogun Aydingun ◽  
Korhan Adalier
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Analysis Procedure ◽  
Finite Element Code ◽  
Remedial Measures ◽  
Foundation Soil ◽  
Benchmark Model ◽  
Numerical Predictions ◽  
Earth Embankment ◽  
Fully Coupled

A numerical analysis has been performed for a clayey embankment founded on a liquefiable foundation soil using an effective stress based, fully coupled, finite element code called DIANA-SWANDYNE II. The results were compared with data obtained from centrifuge experiments. In Part I, the numerical method and the analysis procedure are explained. The results obtained for a series of three consecutive, increasing amplitude shaking events are presented. An attempt has been made to calibrate a benchmark model to be used in the application of different remedial measures which are discussed in Part II. The numerical predictions compared well with the experimental data and provided further insights into the dynamic behavior of embankment–foundation systems.Key words: liquefaction, numerical modeling, coupled formulation, centrifuge, embankment, earthquakes.

Implementation of Liquid Metal Properties in RELAP5 MOD3.2 for Safety Analysis of Sodium-Cooled Fast Reactors

2017 ◽  
Author(s):  
Jian Song ◽  
Limin Liu ◽  
Simiao Tang ◽  
Yingwei Wu ◽  
Wenxi Tian ◽  
...  
Keyword(s):  
Experimental Data ◽  
Liquid Metal ◽  
Fast Reactor ◽  
Natural Circulation ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Working Fluid ◽  
Primary System ◽  
Steady State Condition ◽  
Design Values

Due to great deal of operation experience and technology accumulation, sodium cooled fast reactor (SFR) is the most promising among the six Generation IV reactors, which has advantages of breeding nuclear fuel, transmuting long-lived actinides and good safety characteristics. Thermal-hydraulic computer codes will have to be developed, verified, and validated to support the conceptual and final designs of new SFRs. However, work on developing thermal hydraulic analysis code for SFR is very limited in China, while the common software RELAP5 MOD3 is unable to analyze liquid metal systems. So the modified RELAP5 MOD3.2 is being considered as the thermal-hydraulic system code to support the development of the SFRs. The thermodynamic and transport properties of sodium liquid and vapor have been implemented into the RELAP5 MOD3.2 code, as well as the specific heat transfer correlations for liquid metal. The sodium liquid properties use polynomial equations based on data obtained from Argonne National Laboratory, and the vapor is assumed to be perfect gas. The property equations are acceptably accurate for analysis of SFR, especially for single-phase liquid. New files are added to the fluids directory to generate property tables for new working fluid, which are similar to the table interpolation subroutines for light and heavy water in the original file directory. The method of code modifications are universal for other working fluids and will not affect the code original performance. Some basic verification work for the modified code are carried out. The steam generator of CEFR is analyzed to verify the modified code. The calculated results show that all the water will boil off in the evaporator and the calculated results are in good agreement with the design values. By using modified RELAP5 to model the primary loop of EBR-II fast reactor, the SHRT-17 PLOF test was analyzed. The results show that the natural circulation can be established in the EBR-II primary system after main pumps off to remove the core decay residual heat effectively, and the peak temperature under the safety limits. Moreover, the results computed in this work compared well with the test experimental data for the steady state condition. During the transients, the changing trends of temperature and pressure are similar to experimental data. The discrepancies between calculation and experiment are considered acceptably which need to be improved in the future work. Our work could demonstrate the capability and reliability of the modified RELAP5 for the analysis of SFRs further.

Assessment of Cooling Tower Discharge Recirculation and Dispersion Using CFD Techniques

2015 ◽  
Author(s):  
S. Pal ◽  
L. J. Peltier ◽  
A. Rizhakov ◽  
M. P. Kinzel ◽  
M. H. Elbert ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cooling Tower ◽  
Cross Flow ◽  
Bluff Bodies ◽  
Cooling Towers ◽  
Design Strategies ◽  
Worst Case ◽  
Buoyant Jets ◽  
Design Values ◽  
High Reynolds

The performance of cooling towers, whether operating by themselves, or in close vicinity of other cooling towers can be adversely affected by the re-ingestion of the cooling tower discharge into the tower intakes. The recirculation of the discharge from a wet cooling tower raises the wet bulb temperature of the air entering a wet cooling tower. Current design strategies, often account for this discharge re-ingestion issue, through a conservative adjustment to the far field ambient wet bulb temperature to calculate the actual intake wet bulb temperature. Critical applications, such as those related to nuclear safety applications where there is concern about cooling tower performance, may require more accurate and comprehensive assessment of the recirculation and dispersion of cooling tower discharge. Gaussian plume models alone are of limited use when dealing with discharges in the vicinity of large structures. This paper discusses the use of a computational fluid dynamics approach to evaluate worst case discharge recirculation effects in cooling towers. The bounding design values of tower intake wet bulb temperature increase due to recirculation (ingestion of tower’s own discharge), and interference (ingestion of another interfering tower’s discharge), are calculated considering the various conditions of cooling tower operation, ambient temperature, humidity and wind conditions. The RANS CFD model used in the study is evaluated against published experimental data for flow over bluff bodies at high Reynolds numbers, and experimental data on buoyant jets in cross flow.

scholarly journals An Intelligent/Learning Axial Fan Design System

1991 ◽  
Author(s):  
Dennis G. Jackson ◽  
Terry Wright
Keyword(s):  
Design Process ◽  
Design Parameters ◽  
Design System ◽  
Preliminary Design ◽  
Axial Fan ◽  
Design Program ◽  
Current Design ◽  
Computer Based ◽  
Refinement Process ◽  
Blade Element

A computer-based axial fan design system has been developed that allows the designer to rapidly obtain a preliminary axial fan design. Program FANDES allows the designer two options to determine the preliminary design parameters for a single-stage axial fan. The first option allows the designer the ability to design an axial fan using conventional blade-element design techniques. The second option enables the designer to search a database of previously designed fans for a set of scaled fans that will satisfy the current design point requirements. The designer can then refine one of the fans in this set to possibly improve the selected fan’s performance. The database of fans is utilized and maintained by FANDES and new fans are added at the user’s request. This allows for an intelligent program that is constantly learning from previous designs. As more fans are designed and saved to the database the design process becomes more of a selection and refinement process of previously designed fans.

Integration of Measurements and Maneuvering Technologies Used to Modify Caisson

1993 ◽  
Vol 9 (03) ◽  
pp. 181-187
Author(s):  
Joseph Krulikowski ◽  
Peter Sparacino ◽  
Anthony Giordano
Keyword(s):  
Computer Aided Design ◽  
Design System ◽  
Accurate Data ◽  
Design Information ◽  
Large Structures ◽  
Final Assembly ◽  
Computer Aided ◽  
Computer Based ◽  
Dry Dock ◽  
Aided Design

The modification of the caisson in a dry dock is in many ways more difficult than conventional ship modifications. This is because of the accuracy required, location of the measurements, and the size of the structure. The development of computer-based multi-headed electronic theodolite systems made it possible to extract accurate data on large structures. These data were formatted so they could be input directly into a computer-aided design system. The multi-headed electronic theodolite system was used to transfer new design information directly to the structure. The caisson structure was modified and moved safely into position with the aid of a water castor system for final assembly. Final dimension checks verified the accuracy of the system.

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