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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


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

AC Loss Analysis on the Superconducting Coupling Magnet in MICE

Description: A pair of coupling solenoids is used in MICE experiment to generate magnetic field which keeps the muons within the iris of thin RF cavity windows. The coupling solenoids have a 1.5-meter inner diameter and will produce 7.4 T peak magnetic field. Three types of AC losses in coupling solenoid are discussed. The affect of AC losses on the temperature distribution within the cold mass during charging and rapid discharging process is analyzed also. The analysis result will be further confirmed by the experiment of the prototype solenoid for coupling solenoid, which will be designed, fabricated and tested at ICST.
Date: July 8, 2008
Creator: Wu, Hong; Wang, Li; Green, Michael; Li, LanKai; Xu, FengYu; Liu, XiaoKun et al.
Partner: UNT Libraries Government Documents Department

Development of the Instrumentation and Modeling for Heat Transfer Characteristics in CFBC

Description: This technical report summarizes the research conducted and results obtained during the period beginning October 1, 1999 to March 31, 2000. Heat transfer characteristics study and experimental work were continued using the bench-scale CFB system with the heat transfer probe. A copper tube with thermocouples was used as the heat transfer probe which was convenient to measure the temperature changes at different locations of the bed. The heat transfer coefficient at different locations of the heat transferring surface decreases along the slides down the heat transfer surface; its temperature increase, which reducing the temperature difference between the surface of the tube and the bulk of the bed. The radial variation of heat transfer coefficients showed little increase in heat transfer coefficient near the wall. It is believed that a long heat-transferring surface is located in the core region; a boundary layer develops near the wall of the surface. This may cause clusters or streamers to form which slides down the surface. According to the results, heat transfer coefficients in the core region are not affected significantly by the location of the probe. The wall conduction resistance was eliminated and heat transfer coefficients were measured and calculated at different locations along the bed height. Heat transfer coefficients near the wall area of the bed are decreased along with the length of the probe. Heat transfer coefficient was slightly dropped when the probe was moved from the wall area to the central area of the bed.
Date: March 29, 2000
Creator: Lee, Seong E.
Partner: UNT Libraries Government Documents Department

Laboratory simulations of supernova shockwaves: Formation of a second shock ahead of a radiative shock

Description: Supernovae launch spherical shocks into the circumstellar medium (CSM). These shocks may interact with both the intergalactic magnetic field (IGM) and local mass accumulations (possibly with their own local magnetic fields). The latter interaction may trigger star formation. The shocks have high Mach numbers and may be radiative. We have created similar shocks in the laboratory by focusing laser pulses onto the tip of a solid pin surrounded by ambient gas; ablated material from the pin rapidly expands and launches a shock through the surrounding gas. The shock may then be allowed to interact with (a) mass accumulations, (b) magnetic fields, or (c) allowed to expand freely. We will present examples of each type of experiment, but mainly discuss a new phenomena observed first in (c); at the edge of the radiatively heated gas ahead of the shock, a second shock forms. The two expanding shocks are simultaneously visible for a time, until the original shock stalls from running into the heated gas. The second shock remains visible and continues to expand. A minimum condition for the formation of the second shock is that the original shock is super-critical, i.e., the temperature distribution ahead of the original shock has an inflexion point. In a non-radiative control experiment the second shock does not form.
Date: January 28, 2005
Creator: Hansen, J F; Edwards, M J; Froula, D; Gregori, G; Edens, A & Ditmire, T
Partner: UNT Libraries Government Documents Department

Over Voltage in a Multi-sectioned Solenoid during a Quenching

Description: Accurate analysis of over voltage in the superconducting solenoid during a quench is one of the bases for quench protection system design. Classical quench simulation methods can only give rough estimation of the over voltage within a magnet coil. In this paper, for multi-sectioned superconducting solenoid, based on the classical assumption of ellipsoidal normal zone, three-dimension al temperature results are mapped to the one-dimension of the wire, the temperature distribution along the wire and the resistances of each turn are obtained. The coil is treated as circuit comprised of turn resistances, turn self and mutual inductances. The turn resistive voltage, turn inductive voltage, and turn resultant voltage along the wire are calculated. As a result, maximum internal voltages, the layer-to-layer voltages and the turn-to-turn voltages are better estimated. Utilizing this method, the over voltage of a small solenoid and a large solenoid during quenching have been studied. The result shows that this method can well improve the over voltage estimate, especially when the coil is larger.
Date: June 21, 2009
Creator: Guo, Xinglong; Wang, Li; Pan, Heng; Wu, Hong; Liu, Xiaokun; Chen, Anbin et al.
Partner: UNT Libraries Government Documents Department


Description: The integrity of coatings used in hot section components of combustion turbines is crucial to the reliability of the buckets. This project was initiated in recognition of the need for predicting the life of coatings analytically, and non-destructively; correspondingly, four principal tasks were established. Task 1, with the objective of analytically developing stress, strain and temperature distributions in the bucket and thereby predicting thermal fatigue (TMF) damage for various operating conditions; Task 2 with the objective of developing eddy current techniques to measure both TMF damage and general degradation of coatings and, Task 3 with the objective of developing mechanism based algorithms. Task 4 is aimed at verifying analytical predictions from Task 1 and the NDE predictions from Task 3 against field observations.
Date: March 31, 2006
Creator: Gandy, D.; Viswanathan, R.; Cheruvu, S. & Krzywosz, K.
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
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