97 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Fluid Mechanics"  
Results: 1 - 24 next
open access

Natural convection phenomena in a nuclear power plant during a postulated TMLB' accident

Description: After the TMI (Three Mile Island) accident, there has been significant interest in analyzing and understanding the phenomena that may occur in a PWR (Pressurized Water Reactor) accident which may lead to partial or total core meltdown and degradation. Natural convection is one of the important phenomena. In the present paper the results of two numerical simulations of (1) four-loop PWR and (2) three-loop PWR are presented. The simulations were performed with the COMMIX(2) computer code. Our ana… more
Date: January 1, 1987
Creator: Domanus, H. M.; Schmitt, R. C.; Sha, W. T.; Shah, V. L. & Han, J. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Revised Users Manual, Pulverized Coal Gasification or Combustion: 2-Dimensional (87-PCGC-2): Final Report, Volume 2. [87-PCGC-2]

Description: A two-dimensional, steady-state model for describing a variety of reactive and non-reactive flows, including pulverized coal combustion and gasification, is presented. Recent code revisions and additions are described. The model, referred to as 87-PCGC-2, is applicable to cylindrical axi-symmetric systems. Turbulence is accounted for in both the fluid mechanics equations and the combustion scheme. Radiation from gases, walls, and particles is taken into account using either a flux method or dis… more
Date: December 1, 1987
Creator: Smith, P. J.; Smoot, L. D. & Brewster, B. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Results of two-phase natural circulation in hot-leg U-bend simulation experiments

Description: In order to study the two-phase natural circulation and flow termination during a small break loss of coolant accident in LWR, simulation experiments have been performed using two different thermal-hydraulic loops. The main focus of the experiment was the two-phase flow behavior in the hot-leg U-bend typical of BandW LWR systems. The first group of experiments was carried out in the nitrogen gas-water adiabatic simulation loop and the second in the Freon 113 boiling and condensation loop. Both … more
Date: January 1, 1987
Creator: Ishii, M.; Lee, S. Y. & Abou El-Seoud, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Quench detection by fluid dynamic means in cable-in-conduit superconductors

Description: The tight confinement of the helium in cable-in-conduit superconductors creates protection problems because of the substantial pressure rise that can occur during a quench. But the same pressure rise offers the useful possibility of a non-electrical means of detecting incipient quenches by monitoring the outflow from the various hydraulic paths of the magnet. If the method is to work, the signal must be large enough to be detected unambiguously at an early enough time, and the signal must not d… more
Date: June 1, 1987
Creator: Dresner, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Evaluation of postulated LOF (loss-of-flow) events in PRISM and SAFR

Description: The PRISM and SAFR designs, as currently proposed by DOE, are designed for ''inherent'', as opposed to ''engineered'', safety. Brookhaven National Laboratory is supporting the initial NRC review of these advanced LMR concepts. A loss-of-flow (LOF) accident coupled with a failure of the reactor shutdown system is one of the major safety concerns in the advanced liquid metal reactor (LMR) evaluation effort. The analysis discussed here covers: (1) primary pipe break without pump trip, (2) primary … more
Date: January 1, 1987
Creator: Chan, B. C.; Van Tuyle, G. J.; Slovik, G. C. & Aronson, A. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hybrid simulations

Description: The philosophy and numerical implementation of hybrid algorithms are reviewed. In the hybrid approximation, a plasma is described by a set of discrete equations, equivalent to a Vlasov-fluid system. The dynamics of one or more species are modeled using moment equations, while the remaining species are treated as a large number of individual macro-particles. In this paper the hybrid method will be compared to fluid and particle-in-cell algorithms, and the strengths and weaknesses of the various … more
Date: January 1, 1987
Creator: Quest, K. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Uncertainties in modeling and scaling in the prediction of fuel stored energy and thermal response

Description: The steady-state temperature distribution and the stored energy in nuclear fuel elements are computed by analytical methods and used to rank, in the order of importance, the effects on stored energy from statistical uncertainties in modeling parameters, in boundary and in operating conditions. An integral technique is used to calculate the transient fuel temperature and to estimate the uncertainties in predicting the fuel thermal response and the peak clad temperature during a large-break loss … more
Date: January 1, 1987
Creator: Wulff, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Reduction of erosion in elbows due to flow modifications: Final report, Phase 1. [Elbows]

Description: The objective of this project is to investigate the concept of flow-field modification as a method for reducing erosion in bends (elbows) used in pneumatic transport systems. Flow field modifications were primarily accomplished by injecting air at selected locations within the bends. Part I of this project shows the feasibility of the concept. Part II of this project will include further experiments and analysis, leading to a design methodology for incorporating this concept into piping systems… more
Date: November 1, 1987
Creator: Johnson, E. K.; Means, K. H.; Eyler, R. L. & Holtzworth, J. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

MINET (Momentum Integral NETwork) analysis of MHTGR (Modular High Temperature Gas-Cooled Reactor) moisture-ingress transient

Description: The transient which involved a steam-generator tube leak and the ingress of moisture into the primary coolant system of the standard Modular Modular High Temperature Gas-Cooled Reactor (MHTGR) is analyzed by using the MINET (Momentum Integral NETwork) computer code. The analysis provides detailed information on the effect of power excursion on transient system pressures and temperatures. It is concluded that during the short term transient period the moisture ingress presents no threat to the i… more
Date: January 1, 1987
Creator: Yang, J. W.; Kroeger, P. G.; Van Tuyle, G. J. & Aronson, A. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Analysis of fission product release behavior during the TMI-2 accident

Description: An analysis of fission product release during the Three Mile Island Unit 2 (TMI-2) accident has been initiated to provide an understanding of fission product behavior that is consistent with both the best estimate accident scenario and fission product results from the ongoing sample acquisition and examination efforts. ''First principles'' fission product release models are used to describe release from intact, disrupted, and molten fuel. Conclusions relating to fission prod… more
Date: January 1, 1987
Creator: Petti, D. A.; Adams, J. P.; Anderson, J. L. & Hobbins, R. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Potential impacts of artificial intelligence expert systems on geothermal well drilling costs:

Description: The Geothermal research Program of the US Department of Energy (DOE) has as one of its goals to reduce the cost of drilling geothermal wells by 25 percent. To attain this goal, DOE continuously evaluates new technologies to determine their potential in contributing to the Program. One such technology is artifical intelligence (AI), a branch of computer science that, in recent years, has begun to impact the marketplace in a number of fields. Expert systems techniques can (and in some cases, alre… more
Date: November 24, 1987
Creator: Satrape, J.V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Study of Resistive Pressure-Gradient-Driven Turbulence

Description: Previous studies have shown the resistive pressure-gradient-driven turbulence (RPGDT) is a likely cause of observed turbulent fluctuations and anomalous transport in magnetically confined plasmas. More recent study of RPGDT found a true saturation criterion and predicted significantly larger pressure diffusivity over simple mixing-length estimate. In this study, we investigate wavenumber spectrum for more detailed characteristics of this driven turbulence and consider an electromagnetic model w… more
Date: January 1, 1987
Creator: Lee, G. S.; Garcia, L.; Carreras, B. A. & Diamond, P. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

COMMIX analysis of the Sodium Heated Helical Coil Steam Generator

Description: This paper describes the COMMIX-HCSG computer program and compares predictions to data obtained from performance tests on a 76 MWt Helical Coil Steam Generator (HCSG) test unit. COMMIX-HCSG is a multi-dimensional thermal/hydraulic code that models both steady state and transient operation of an HCSG. The code solves a system of Navier-Stokes continuum equations that have been modified with a combination of volume and directional surface porosities and distributed resistances. This formulation p… more
Date: January 1, 1987
Creator: Kakarala, C. R.; Burge, S. W. & Sha, W. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

ATHENA radiation model

Description: The ATHENA computer program has many features that make it desirable to use as a space reactor evaluation tool. One of the missing features was a surface-to-surface thermal radiation model. A model was developed that allows any of the regular ATHENA heat slabs to radiate to any other heat slab. The view factors and surface emissivities must be specified by the user. To verify that the model was properly accounting for radiant energy transfer, two different types of test calculations were perfor… more
Date: October 1, 1987
Creator: Shumway, R.W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Fundamentals of numerical magnetohydrodynamics

Description: Magnetohydrodynamics is a fluid model for the motion of an ionized gas in a magnetic field. In its ideal, non-dissipative form, the Lundquist equations, it has the same mathematical character as the model for gas dynamics. It gives, in the same way, a self-consistent description of the fluid dynamics, including the exchange of momentum and energy between the field and the fluid. However, because of the greater complexity of the physics which they describe, some aspects of the solutions are quit… more
Date: January 1, 1987
Creator: Brackbill, J.U.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Experimental and analytical studies of passive shutdown heat removal systems

Description: Using a naturally circulating air stream to remove shutdown decay heat from a nuclear reactor vessel is a key feature of advanced liquid metal reactor (LMR) concepts developed by potential vendors selected by the Department of Energy. General Electric and Rockwell International continue to develop innovative design concepts aimed at improving safety, lowering plant costs, simplifying plant operation, reducing construction times, and most of all, enhancing plant licensability. The reactor progra… more
Date: January 1, 1987
Creator: Pedersen, D.; Tessier, J.; Heineman, J.; Stewart, R.; Anderson, T.; August, C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

DHCVIM: A direct heating containment vessel interactions module: Applications to Sandia National Laboratory Surtsey experiments

Description: Direct containment heating is the mechanism of severe nuclear reactor accident containment loading which results from transfer of thermal and chemical energy from high temperature, finely divided, molten core material to the containment atmosphere. The Direct Heating Containment Vessel Interactions Module, DHCVIM, has been developed at BNL to mechanistically model the mechanisms of containment loading resulting from the direct heating accident sequence. The calculational procedure is being used… more
Date: January 1, 1987
Creator: Ginsberg, T. & Tutu, N.K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

SASSYS analysis of EBR-II SHRT experiments

Description: SASSYS is a general purpose one-dimensional thermal-hydraulic LMR systems analysis code. The application of SASSYS to studies of protected and unprotected transient analysis of LMR designs, such as PRISM and SAFR, is commonplace. This usage requires that a strong validation base exist for SASSYS. Validation of a code such as SASSYS is made up of a variety of activities such as, application of separate component models to model problems where the solution is analytically known, cross comparison … more
Date: January 1, 1987
Creator: Hill, D.J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Integrated TRAC/MELPROG analyses of a PWR station blackout

Description: The first complete, coupled, and largely mechanistic analysis of the entire reactor-coolant system during a station blackout (TMLB') core-meltdown accident has been made with MELPROG/TRAC. The calculation was initiated at the start of the transient and ended with a late recovery of cooling. Additional cooling provided by water from the primary system delayed events relative to a standalone MELPROG calculation. Natural circulation within the vessel was established and primary-relief-valve action… more
Date: January 1, 1987
Creator: Henninger, R. & Dearing, J.F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Heat engine regenerators: Research status and needs

Description: The rapidly oscillating, variable density flows of regenerative heat engines provide a class of poorly understood unsteady flow and heat transfer problems. These problems are not currently amenable to direct experimental resolution. Experiences in engine development and test programs and efforts to develop analysis tools point to the regenerator as a key area of insufficient understanding. Focusing on flow and heat transfer in regenerators, this report discusses similarity parameters for the fl… more
Date: August 1, 1987
Creator: Hutchinson, R.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Low gravity fluid-thermal experiments

Description: Pacific Northwest Laboratory (PNL) is the lead laboratory for the thermal-hydraulic research in the US Department of Energy Multimegawatt Space Nuclear Power Program. PNL must provide the tools necessary to analyze proposed space reactor concepts, which include single- and two-phase alkali metal and gas-cooled designs. PNL has divided its activities for this task into three basic areas: computer code development, thermal-hydraulic modeling, and experimentation. The subject of this paper is the … more
Date: June 1, 1987
Creator: Krotiuk, W.J. & Cuta, J.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Initial pipe break analyses for advanced LMR (liquid metal reactor) concepts using MINET

Description: In support of an initial NRC review of DOE sponsored advanced liquid metal reactors (LMRs), BNL has performed some very conservative calculations of postulated primary loop pipe breaks using the MINET Code. This report briefly describes the results obtained from these calculations. 5 refs., 2 figs.
Date: June 1, 1987
Creator: Van Tuyle, G. J.; Chan, B. C. & Slovik, G. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The history and development of nonlinear stellar pulsation codes

Description: This review is limited to the history and development of nonlinear stellar pulsation codes and methods. The narrative includes examples of practical interest in the application of these numerical methods to problems in stellar pulsation such as Cepheid mass discrepancy, the delineation of the RR Lyrae instability strip, and the question of the development of double-mode pulsation as observed in Cepheids, RR Lyrae and other variable stars. 15 refs.
Date: January 1, 1987
Creator: Davis, C.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Mechanistic model for void distribution in flashing flow

Description: A problem of discharging of an initially subcooled liquid from a high pressure condition into a low pressure environment is quite important in several industrial systems such as nuclear reactors and chemical reactors. A new model for the flashing process is proposed here based on the wall nucleation theory, bubble growth model and drift-flux bubble transport model. In order to calculate the bubble number density, the bubble number transport equation with a distributed source from the wall nucle… more
Date: January 1, 1987
Creator: Riznic, J.; Ishii, M. & Afgan, N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen