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Effect of air distribution on radial temperature distribution in one-sixth sector of annular turbojet combustor

Description: Report presenting an experimental investigation in a one-sixth sector of an annular turbojet combustor to determine a method of controlling radial exhaust-gas-temperature distribution in a gas-turbine combustion chamber. The adjustment in controlling air was made by ducting the dilution air into the combustion zone in a predetermined manner through hollow radial struts or by modifying the basket-wall open-hole area. Results regarding the temperature distribution, temperature-rise efficiency, total-pressure loss, and altitude operating limits are provided.
Date: April 5, 1950
Creator: Mark, Herman & Zettle, Eugene V.
Partner: UNT Libraries Government Documents Department

The Location of the Maximum Temperature on the Cutting Edges of a Drill

Description: This study analyzes the temperature profile along the cutting edges of a drill and describes how the temperature on the chisel edge can exceed the temperature on the primary cutting edges. A finite element model predicts the temperature distribution in the drill, where the heat flux loads applied to the finite element model are determined from analytical equations. The model for the heat flux loads considers both the heat generated on the shear plane and the heat generated on the rake face of the tool to determine the amount of heat flowing into the tool on each segment of the cutting edges. Contrary to the conventional belief that the maximum temperature occurs near the outer corner of the drill, the model predicts that the maximum temperature occurs on the chisel edge, which is consistent with experimental measurements of the temperature profile.
Date: January 7, 2005
Creator: Bono, M J & Ni, J
Partner: UNT Libraries Government Documents Department

Distribution of excess temperature from the Morgantown Generating Station on the Potomac Estuary

Description: Research undertaken to determine the effects of thermal effluents on the temperature distribution in estuarine waters is described. Procedures for and results from measurements of the temperature, river flow, tidal currents, salinity, wind, etc at the Potomac River estuary in 1969 and 1972, which represent pre- and post-operation conditions for the operation of the fossil- fueled Morgantown power plant, are reported. (LC L)
Date: October 1, 1973
Creator: Carter, H.H.
Partner: UNT Libraries Government Documents Department

Effect of Flux Adjustments on Temperature Variability in Climate Models

Description: It has been suggested that ''flux adjustments'' in climate models suppress simulated temperature variability. If true, this might invalidate the conclusion that at least some of observed temperature increases since 1860 are anthropogenic, since this conclusion is based in part on estimates of natural temperature variability derived from flux-adjusted models. We assess variability of surface air temperatures in 17 simulations of internal temperature variability submitted to the Coupled Model Intercomparison Project. By comparing variability in flux-adjusted vs. non-flux adjusted simulations, we find no evidence that flux adjustments suppress temperature variability in climate models; other, largely unknown, factors are much more important in determining simulated temperature variability. Therefore the conclusion that at least some of observed temperature increases are anthropogenic cannot be questioned on the grounds that it is based in part on results of flux-adjusted models. Also, reducing or eliminating flux adjustments would probably do little to improve simulations of temperature variability.
Date: December 27, 1999
Creator: Duffy, P.; Bell, J.; Covey, C. & Sloan, L.
Partner: UNT Libraries Government Documents Department

Bursting Frequency Predictions for Compressible Turbulent Boundary Layers

Description: A computational method for the prediction of the bursting frequency associated with the coherent streamwise structures in high-speed compressible turbulent boundary layers is presented. The structures are described as wavelike disturbances of the turbulent mean flow. A direct resonance theory is used to determine the frequency of bursting. The resulting hydrodynamic linear stability equations are discretized by using a Chebyshev collocation method. A global numerical method capable of resolving the entire eigenvalue spectrum is used. Realistic turbulent mean velocity and temperature profiles are applied. For all of the compressible turbulent boundary layers calculated, the results show at least one frequency that satisfies the resonance condition. A second frequency can be identified for cases with high Reynolds numbers. An estimate is also made for the profile distribution of the temperature disturbance.
Date: October 1, 2002
Creator: LIOU, WILLIAM W. & FANG, YICHUAN
Partner: UNT Libraries Government Documents Department

Parametric thermal evaluations of waste package emplacement

Description: Parametric thermal evaluations of spent nuclear fuel (SNF) waste packages (WPs) emplaced in the potential repository were performed to determine the impact of thermal loading, WP spacing, drift diameter, SNF aging, backfill, and relocation on the design of the Engineered Barrier System. Temperatures in the WP and near-field host rock are key to radionuclide containment, as they directly affect oxidation rates of the metal barriers and the ability of the rock to impede particle movement which must be demonstrated for a safe and licensable repository. Maximum allowable temperatures are based on material performance criteria and are specified as the following design goals for the WP/EBS design: SNF cladding 350{degrees}C, drift wall 200{degrees}C, and TSw3 rock 115{degrees}C.
Date: February 1, 1996
Creator: Bahney, R.H. III & Doering, T.W.
Partner: UNT Libraries Government Documents Department

Surface temperatures of insulated glazing units: Infrared thermography laboratory measurements

Description: Data are presented for the distribution of surface temperatures on the warm-side surface of seven different insulated glazing units. Surface temperatures are measured using infrared thermography and an external referencing technique. This technique allows detailed mapping of surface temperatures that is non-intrusive. The glazings were placed between warm and cold environmental chambers that were operated at conditions corresponding to standard design conditions for winter heating. The temperatures conditions are 2 1.1{degrees}C (70{degrees}F) and -17.8{degrees}C (0{degrees}F) on the warm and cold sides, respectively. Film coefficients varied somewhat with average conditions of about 7.6 W/m{sup 2}{circ}K (1.34 Btu/h-ft{sup 2}{circ}{degrees}F) for the warm-side and 28.9 W/m{sup 2}{circ}K (5.1 Btu/h{circ}ft{sup 2}{circ}{degrees}F) for the cold-side. Surface temperature data are plotted for the vertical distribution along the centerline of the IG and for the horizontal distribution along the centerline. This paper is part of larger collaborative effort that studied the same set of glazings.
Date: December 1, 1995
Creator: Griffith, B.T.; Tuerler, D. & Arasteh, D.
Partner: UNT Libraries Government Documents Department

A study of heat transfer for two layered composite inclined plate crotch absorbers

Description: Since a copper plate (Z=29) absorbs most of the photon energy very near the surface, the temperature of the surface becomes very high despite of having a high thermal conductivity. On the other hand, a beryllium plate( Z=4) can diffuse the intense radiation throughout the depth of its plate by allowing photons to penetrate, but has a low thermal conductivity (about half of that of a copper). As an effort to combine both merits of Be and Cu, a Be-Cu composite absorber was developed and has been successfully used in CESR. They analyzed composite the heat transfer problem numerically for the case of a vertically located Be-Cu composite cylinder which results in symmetry with respect to the center of photon beam and allows them to consider only half a domain. In this note, an inclined absorber with two layered metal plates is considered and a full domain solution is sought to study the asymmetric heating due to the inclined photon beam penetration heating. An analytical solution for heat transfer is obtained for a full domain using the Fourier integral transformation and of particular interests are the effects of different thickness ratios of two materials and different inclination angles.
Date: November 1, 1989
Creator: Choi, M.
Partner: UNT Libraries Government Documents Department

Pattern of Thermal Fluctuations in a Recovery Boiler Floor

Description: The floor of a black liquor recovey boiler at a mill in central Canada has experienced cracking and delamination of the composite tubing near the spout wall and deformation of the floor panels that is most severe in the vicinity of the spout wall. One possible explanation for the observed damage is impacts of salt cake falling from the convective section onto the floor. In order to determine if such impacts do occur, strain gauges and thermocouples were installed on the boiler floor in areas where cracking and deformation were most frequent. The data obtained from these instruments indicate that brief, sudden temperature fluctuations do occur, and changes in the strain experienced by the affected tube occur simultaneously. These fluctuations appear to occur less often along the spout wall and more frequently with increasing distance from the wall. The frequency of these temperature fluctuations is insufficient for thermal fatigue to be the sole cause of the cracking observed on the tubes, but the data are consistent with what might be expected from pieces of falling salt cake.
Date: April 25, 1999
Creator: Abdullah, Z.; Gorog, J.P.; Keiser, J.R.; Meyers, L.E. & Swindeman, R.W.
Partner: UNT Libraries Government Documents Department

Electric co-heating in the ASHRAE standard method of test for thermal distribution efficiency: Test results on two New York State homes

Description: Electric co-heating tests on two single-family homes with forced-air heating systems were carried out in March 1995. The goal of these tests was to evaluate procedures being considered for incorporation in a Standard Method of Test for thermal distribution system efficiency now being developed by ASHRAE. Thermal distribution systems are the ductwork, piping, or other means used to transport heat or cooling effect from the building equipment that produces this thermal energy to the spaces in which it is used. Furthering the project goal, the first objective of the tests was to evaluate electric co-heating as a means of measuring system efficiency. The second objective was to investigate procedures for obtaining the distribution efficiency, using system efficiency as a base. Distribution efficiencies of 0.63 and 0.70 were obtained for the two houses.
Date: October 1, 1995
Creator: Andrews, J.W.; Krajewski, R.F. & Strasser, J.J.
Partner: UNT Libraries Government Documents Department

Thermomechanical analysis of the ITER breeding blanket

Description: Thermomechanical performance of the ITER breeding blanket is an important design issue because it requires first, that the thermal expansion mismatch between the blanket structure and the blankets internals (such as, beryllium multiplier and tritium breeders) can be accommodated without creating high stresses, and second, that the thermomechanical deformation of various interfaces within the blanket does not create high resistance to heat flow and consequent unacceptably high temperatures in the blanket materials. Thermomechanical analysis of a single beryllium block sandwiched between two stainless steel plates was carried out using the finite element code ABAQUS to illustrate the importance of elastic deformation on the temperature distributions. Such an analysis for the whole ITER blanket needs to be conducted in the future. Uncertainties in the thermomechanical contact analysis can be reduced by bonding the beryllium blocks to the stainless steel plates by a thin soft interfacial layer.
Date: March 1, 1997
Creator: Majumdar, S.; Gruhn, H.; Gohar, Y. & Giegerich, M.
Partner: UNT Libraries Government Documents Department

A Numerical Analysis of the Single-Well Steam Assisted Gravity Drainage (SW-SAGD) Process, SUPRI TR-124

Description: Results from this study include cumulative recoveries, temperature distributions, and production rates. It was found that cyclic steaming of the reservoir offers the most favorable option for heating the near-wellbore area to create conditions that improve initial SAGD response. More favorable reservoir conditions such as low viscosity, thick oil zones, and solution gas, improved reservoir response. Under unfavorable conditions, response was limited.
Date: July 23, 2001
Creator: Elliot, K.T. & Kovscek, A.R.
Partner: UNT Libraries Government Documents Department

Temperature distribution in a flowing fluid heated in a microwave resonant cavity

Description: This paper presents results of an analytical study of microwave heating of a fluid flowing through a tube situated along the axis of a cylindrical microwave applicator. The interaction of the microwave field pattern and the fluid velocity profiles is illustrated for both laminar and turbulent flow. Resulting temperature profiles are compared with those generated by conventional heating through a surface heat flux. It is found that microwave heating offers several advantages over conventional heating.
Date: April 1, 1996
Creator: Thomas, J.R. Jr.; Nelson, E.M.; Kares, R.J. & Stringfield, R.M.
Partner: UNT Libraries Government Documents Department

Nitrogen system for the SSC

Description: The Superconducting Super Collider consists of two parallel magnet rings, each 87,120 m in circumference, constructed in a tunnel 25 m to 74 m below ground level. They are operated at a controlled low helium temperature in order to maintain the magnet windings in the superconducting state. To obtain this condition, the magnet cryostat is designed with a high-quality insulation obtained by a high vacuum chamber, multilayer insulation, and thermal shields at nominal temperatures of 84 K and 20 K. Thermal radiation and the conduction heat load through the supports are intercepted and absorbed by the 84-K shield. Liquid nitrogen provides the refrigeration for these loads. The 84-K shield is anchored to two 63.5-mm stainless-steel tubes. One of the tubes, the ``liquid line,`` serves as a conduit in the distribution system of liquid nitrogen. The other tube, the ``vapor line,`` is used to collect the nitrogen vapor generated in the cooling process and to supply this vapor to,the helium refrigerators for precooling. The vapor line may also be used as a continuous cooler by injecting controlled amounts of liquid nitrogen. The nitrogen system consists of nitrogen supplies; ten nitrogen dewars for the collider and two for the High Energy Booster located on the ground at the main shaft entrances; liquid and vapor transfer lines through the shaft to connect the surface and the tunnel systems; and transfer lines to bypass warm equipment sections of the collider. The nitrogen system is expected to operate at steady state condition except for cooldown, warmup, and system repair, for which transients are expected. During normal operation and standby modes of the collider, temperature, pressure, and mass flow are expected to be constant in all circuits of the nitrogen system. The conceptual design requirements for various flow schemes and the engineering considerations are presented in ...
Date: October 1, 1992
Creator: McAshan, M.; Thirumaleshwar, M.; Abramovich, S. & Ganni, V.
Partner: UNT Libraries Government Documents Department

Development of characterization of plutonium storage containers

Description: As a result of the end of the Cold War, at least 11,000 (possibly 20,000 or more) plutonium pits are projected to be stored at Pantex for up to fifty years. The current pit container, the ALR8 was not designed for this length of storage duration. As a result, Pantex officials have searched for alternative container options. The objective of this research is to develop and validate a model to predict the temperature distribution within the stored components and the internal structure of the proposed ALR8(SI) container, and to consider and analyze the safety features of the ALR8(SI) container as seen from the thermal performance view. Due to the time scale involved with the current simulations, the radioactive decay of the plutonium may be assumed to provide a uniform rate of heat generation. This heat is conducted to the surroundings through the solid structures of the assembly. In addition to conduction, the inert gas that fills the volume within the steel container convects a fraction of the generated heat from the plutonium to the colder steel surfaces. Radiation must also be accounted for as natural convection and limited conduction paths are present within the container. The research efforts in this project have been directed into two paths, numerical and experimental. First, the temperature distribution within the stored components are being determined experimentally as a function of fill gases, energy generation rate, and boundary conditions. Second, a finite element model of the ALR8 container has been developed so that the temperature distribution can be predicted as a function of the same experimental parameters. This paper presents the experimental method and data that have been obtained thus far, as well as the finite element model created using SDRC I-DEAS.
Date: February 1, 1999
Creator: James, D. & Stevkovski, S.
Partner: UNT Libraries Government Documents Department

A feasibility study for the storage of plutonium pits in non-partitioned warehouse facilities

Description: It is projected that up to 20,000 plutonium pits will be stored at Pantex for up to 50 years. The proposed storage system has to meet longevity, safety and cost requirements. Thermal, mechanical, chemical, nuclear criticality and safety performance characteristics of any proposed plutonium container design need to be formally analyzed. Plutonium generates thermal energy as it decays. The generated thermal energy may cause excessive rise of temperature. For safety and other considerations, it is important that the plutonium temperature remains relatively constant and no hot spots develop. Plutonium containers should not be disassembled for routine monitoring and there are various reasons for the need to monitor the plutonium non-obtrusively. Therefore, accurate predictions of the temperature distribution within the storage container based upon external monitoring within the storage facility needs to be developed. A heat transfer analysis of the storage container is required. The heat transfer analysis, however, requires the knowledge of the temperature and velocity of the air circulating around the containers in order to determine the heat transferred to the air from the containers by convection. Therefore, a complete flow field analysis is required prior to performing the conduction analysis of each pit. The objective of this research is, therefore, to develop and validate a numerical model to predict the temperature distribution within the plutonium storage container as a function of the ambient air temperature within the warehouse.
Date: February 1, 1999
Creator: James, D.; Parameswaran, S. & Nagendran, S.
Partner: UNT Libraries Government Documents Department

Growth curve analysis for plasma profiles using smoothing splines. Final report, January 1993--January 1995

Description: In this project, we parameterize the shape and magnitude of the temperature and density profiles on JET and the temperature profiles on TFTR. The key control variables for the profiles were tabulated and the response functions were estimated. A sophisticated statistical analysis code was developed to fit the plasma profiles. Our analysis indicate that the JET density shape depends primarily on {bar n}/B{sub t} for Ohmic heating, {bar n} for L-mode and I{sub p} for H-mode. The temperature profiles for JET are mainly determined by q{sub 95} for the case of Ohmic heating, and by B{sub t} and P/{bar n} for the L-mode. For the H-mode the shape depends on the type of auxiliary heating, Z{sub eff}, N{bar n}, q{sub 95}, and P.
Date: July 1, 1995
Creator: Imre, K.
Partner: UNT Libraries Government Documents Department

Die Casting Part Distortion: Prediction and Attenuation

Description: The goal of this research was to predict the part deformation and residual stresses after ejection from the die and cooling to room temperature. A finite element model was built to achieve this goal and several modeling techniques were investigated throughout this research. Die-casting is a very complex process and the researchers are faced with a large number of hard to solve physical problems when modeling the process. Several assumptions are made in our simulation model. The first significant assumption is the instantaneous cavity filling. This means that the cavity filling stage is not considered in our model. Considering the cavity filling stage increases the modeling complexity as a result of different flow patterns. expected in the shot sleeve, gate, runner and different cavity features. The flow of gas from the cavity through the vents is another problem that is ignored in our model as a result of this assumption. Our second assumption is that the cast metal has uniform temperature distribution inside the cavity, at the starting point of simulation. This temperature is assumed to be over liquidus limit, i.e. the solid fraction is 0.0% of the cast metal. The third assumption is due to ABAQUS (commercial software used in this research) limitations. ABAQUS cannot deal with multi-phase models; therefore we use solid elements to define the casting instead of multi-phase (liquid/solid) elements. Liquid elements can carry the hydrostatic pressure from the shot sleeve and apply it on the cavity surfaces, while the solid elements do not have this capability. To compensate for this assumption we add the cavity pressure as a boundary condition and apply it on the cavity surface separately from the part. Another issue with this assumption is that, liquid casting can follow the cavity shape when it distorts. With the use of solid elements to ...
Date: February 12, 2002
Creator: Dr, R. Allen Miller
Partner: UNT Libraries Government Documents Department

HIERARCHICAL METHODOLOGY FOR MODELING HYDROGEN STORAGE SYSTEMS. PART I: SCOPING MODELS

Description: Detailed models for hydrogen storage systems provide essential design information about flow and temperature distributions, as well as, the utilization of a hydrogen storage media. However, before constructing a detailed model it is necessary to know the geometry and length scales of the system, along with its heat transfer requirements, which depend on the limiting reaction kinetics. More fundamentally, before committing significant time and resources to the development of a detailed model, it is necessary to know whether a conceptual storage system design is viable. For this reason, a hierarchical system of models progressing from scoping models to detailed analyses was developed. This paper, which discusses the scoping models, is the first in a two part series that presents a collection of hierarchical models for the design and evaluation of hydrogen storage systems.
Date: December 22, 2008
Creator: Hardy, B & Donald L. Anton, D
Partner: UNT Libraries Government Documents Department