Transient Heat Transfer Analysis of Alloy Solidification

1973 ◽  
Vol 95 (3) ◽  
pp. 324-331 ◽  
Author(s):  
J. C. Muehlbauer ◽  
J. D. Hatcher ◽  
D. W. Lyons ◽  
J. E. Sunderland
Keyword(s):  
Temperature Distribution ◽  
Eutectic Composition ◽  
Approximate Solutions ◽  
The Other ◽  
Heat Transfer Analysis ◽  
Uniform Temperature ◽  
One Dimensional ◽  
Temperature Distributions ◽  
Finite Slab ◽  
Good Agreement

Approximate solutions are obtained for the temperature distribution and rate of phase change for the transient one-dimensional solidification of a finite slab of a binary alloy. The alloy is selected to avoid the eutectic composition so that solidification takes place over a range of temperatures. The slab is initially superheated and has a uniform temperature distribution. Solidification occurs after one surface is cooled by convection while the other surface is insulated. Temperature distributions are determined analytically and experimentally and are in reasonably good agreement.

Examination of Oscillating Frequencies Generated by Combustion Oscillation Considering Temperature Distribution in a Combustor Tube Fueled by Natural Gas and Hydrogen Mixture

2020 ◽  
Author(s):  
Akane Uemichi ◽  
Kan Mitani ◽  
Yudai Yamasaki ◽  
Shigehiko Kaneko
Keyword(s):  
Temperature Distribution ◽  
Natural Gas ◽  
Transfer Matrix ◽  
Fuel Mixture ◽  
One Dimensional ◽  
Temperature Distributions ◽  
Combustion Oscillation ◽  
The Town ◽  
Small Elements ◽  
Oscillation Experiment

Abstract A combustion oscillation experiment fueling a mixture of hydrogen and natural gas was performed. The results showed oscillating frequencies of around 350 Hz in the case of the town gas only, whereas oscillating frequencies of around 200 and 400 Hz were observed in the hydrogen-containing fuel case. We hypothesized that the oscillating frequencies shift may occur by changing the temperature-distribution inside the tube, which was caused by different combustion conditions with the fuel mixture. As a result, the possible oscillating frequencies of not only around 350 Hz but also around 200 and 400 Hz were obtained. Although three types of possible oscillating frequencies were obtained in our previous study, more detailed temperature distributions should be considered to clarify the effect of the changing fuel mixture composition. In this paper, representative one-dimensional temperature distributions were formed by the combination of measured and calculated temperature distributions in the combustion tube for the corresponding fuel mixture. To include the detailed temperature distributions, the acoustic network model was divided into enough small elements to express the temperature distributions, where each element was connected by the transfer matrix. Then, the possible oscillating frequencies were calculated, taking account of the influence of the temperature distributions.

Transient Heat Conduction in an Infinite Plate With a Transverse Circular Cylindrical Hole

1973 ◽  
Vol 95 (3) ◽  
pp. 414-416 ◽  
Author(s):  
C. D. Michalopoulos ◽  
J. J. Seco
Keyword(s):  
Heat Conduction ◽  
Temperature Distribution ◽  
Infinite Plate ◽  
Transient Heat Conduction ◽  
Cylindrical Hole ◽  
The Other ◽  
Graphical Form ◽  
Zero Temperature ◽  
Temperature Distributions ◽  
Axisymmetric Temperature

The flow of heat in an infinite plate with a transverse circular cylindrical hole is considered. The boundary conditions are zero temperature on the cylindrical surface and arbitrary but axisymmetric temperature distributions on the plane surfaces. The solution is obtained by means of Laplace and an unconventional Hankel transforms. Numerical results are given in graphical form for a plate with a step temperature distribution on one face and zero temperature on the other.

Predicting the temperature distribution and suction gas superheating of an oil-free linear compressor

2016 ◽  
Vol 231 (1) ◽  
pp. 47-56 ◽  
Author(s):  
MJ Oliveira ◽  
MC Diniz ◽  
CJ Deschamps
Keyword(s):  
Temperature Distribution ◽  
Gas Flow ◽  
The Other ◽  
Design Parameters ◽  
Linear Compressor ◽  
Discharge System ◽  
Experimental Calibration ◽  
Compression Cycle ◽  
Volume Method ◽  
Good Agreement

It is well established that the volumetric and isentropic efficiencies of reciprocating compressors used for household refrigeration are significantly reduced by suction gas superheating. Moreover, excessive levels of temperature may affect the reliability of some components, such as the electrical motor. This paper reports a modeling approach to predict the temperature distribution in the gas and solid components of an oil-free linear compressor. A simulation model based on the finite volume method was used to solve the heat conduction in the solid components and gas flow inside the compressor. On the other hand, the compression cycle in the cylinder was solved with a transient lumped formulation, but in a coupled manner with the remainder of the solution domain. The prediction of the suction gas superheating obtained with the model was in good agreement with the measurements, despite discrepancies being observed in some solid components and in the gas path along the discharge system. The model does not require any experimental calibration and hence is suitable to analyze different compressor designs. To illustrate this, the model was applied to predict the temperature distribution with respect to two design parameters.

Combined Mode Heat Transfer Analysis Utilizing Radiation Scaling

1986 ◽  
Vol 108 (3) ◽  
pp. 626-632 ◽  
Author(s):  
H. Lee ◽  
R. O. Buckius
Keyword(s):  
Heat Transfer ◽  
Scaling Laws ◽  
Radiant Heat ◽  
Heat Fluxes ◽  
Heat Transfer Analysis ◽  
Incident Intensity ◽  
One Dimensional ◽  
Flow Problems ◽  
Combined Mode ◽  
Good Agreement

Scaling laws have been formulated to predict the radiant heat flux in anisotropically scattering, one-dimensional planar media [1, 2]. The radiation portion of the problem is reduced to an equivalent nonscattering problem by the scaling. The same scaling laws are applied to problems when radiation is combined with other modes of heat transfer, requiring the solution of the energy equation for a temperature profile. The average incident intensity is accurately scaled by a multilayer approach. Results presented for radiation/conduction and the thermally developing Poiseuille flow problems show very good agreement between exact and scaled solutions for heat fluxes and temperature distributions.

Pulse Propagation in Inhomogeneous Media

1974 ◽  
Vol 41 (4) ◽  
pp. 1057-1062 ◽  
Author(s):  
D. B. Longcope ◽  
C. R. Steele
Keyword(s):  
Exact Solution ◽  
Opposite Direction ◽  
Wave Speed ◽  
Pulse Propagation ◽  
Characteristic Length ◽  
Pulse Length ◽  
Approximate Solutions ◽  
The Other ◽  
One Dimensional ◽  
Analytic Wave

Approximate solutions are developed for one-dimensional pulse propagation in a medium with an analytic wave speed when the ratio ε of the pulse length to a characteristic length of the wave speed variation is small. The solutions describe an 0(1) transmitted pulse, given by the WKB solution, and an 0(ε) reflection which may progress in the opposite direction. Two approximations for the reflection are given, one in terms of explicit integrals and the other, which may be uniformly valid, by a combination of explicit integrals and a slowly varying numerical term. Comparisons with the exact solution in several examples show the usefulness of the approximate solutions.

scholarly journals Parameterisation of the residual temperature distribution based on the modelling of successive emission of prompt neutrons

2018 ◽  
Vol 169 ◽  
pp. 00025 ◽  
Author(s):  
Anabella Tudora ◽  
Franz-Josef Hambsch
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Temperature Distribution ◽  
Los Alamos ◽  
Temperature Distributions ◽  
Residual Temperature ◽  
Deterministic Modelling ◽  
Prompt Emission ◽  
Good Agreement

A new deterministic modelling taking into account the successive emission of prompt neutrons from initial fragments of a fragmentation range {A, Z, TKE} constructed as in the Point-by-Point (PbP) treatment is described. The good agreement of different prompt emission quantities obtained from this modelling (e.g. v(A), v(TKE), E-γ(A), E-γ(TKE), etc.) with the experimental data and the results of the PbP model and other Monte-Carlo models validates the present modelling of sequential emission. The distributions of different residual quantities, including the residual temperature distributions P(T) of light and heavy fragments allow to obtain a new parameterisation of P(T) which can be used in the PbP model and the Los Alamos model.

Laminar Natural Convection in an Inclined Rectangular Box With the Lower Surface Half-Heated and Half-Insulated

1983 ◽  
Vol 105 (3) ◽  
pp. 425-432 ◽  
Author(s):  
P. K.-B. Chao ◽  
H. Ozoe ◽  
S. W. Churchill ◽  
N. Lior
Keyword(s):  
Heat Transfer ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Lower Surface ◽  
The Other ◽  
Uniform Temperature ◽  
Side Walls ◽  
Laminar Natural Convection ◽  
Rayleigh Numbers ◽  
Good Agreement

The pattern of circulation and the rate of heat transfer were determined experimentally and also by three-dimensional, finite-difference calculations for an inclined 2 × 1 × 1 rectangular enclosure with a 1 × 1 segment of the lower 2 × 1 surface at a uniform temperature, the other 1 × 1 segment and four side walls insulated, and the upper surface at a lower uniform temperature. As contrasted with an enclosure heated and cooled on the horizontal surfaces, a fluid motion occurs and the rate of heat transfer exceeds that for pure conduction for all temperature differences and orientations. The effects of elevation of the heated and insulated segments were investigated, as well as of inclination about the longer dimension. Despite differences in the Prandtl and Rayleigh numbers, the observed and predicted patterns of circulation are in good agreement, and the measured and predicted rates of heat are in qualitative agreement.

Impact of Cargo Stacking Modes on Temperature Distribution Inside Marine Reefer Containers

2017 ◽  
Vol 25 (03) ◽  
pp. 1750020 ◽  
Author(s):  
Ankang Kan ◽  
Jin Hu ◽  
Zhipeng Guo ◽  
Chuang Meng ◽  
Chen Chao
Keyword(s):  
Temperature Distribution ◽  
Heat Release ◽  
Internal Temperature ◽  
Temperature Distributions ◽  
Key Factor ◽  
Simulation Results ◽  
Cfd Method ◽  
Sidewall Surface ◽  
Good Agreement

The refrigerated/chilled quality of marine cargo is vitally influenced by the temperature distribution inside reefer container. The stacking mode is a key factor affecting temperature distribution. CFD method is employed to model and simulate a 20-ft standard reefer container, in which seven cargo stacking modes are emulated to numerically analyze the internal temperature distribution inside the container. The stacking cargo is assumed as solid stack without heat release and the variables, such as stack number, height, length and gap, are considered in seven simulation cases. The results show that the temperature distributions become disordered along with increase in the stack height; the temperature difference increase along with increase in the stack length; the temperature tends to be isothermal when the gap of the stacks or the space between the stack and sidewall surface is enlarging. The simulation results are in very good agreement with the experimental results.

Effect of Rake Face Design on Cutting Tool Temperature Distributions

1980 ◽  
Vol 102 (2) ◽  
pp. 123-128 ◽  
Author(s):  
P. K. Wright ◽  
S. P. McCormick ◽  
T. R. Miller
Keyword(s):  
Temperature Distribution ◽  
Cutting Tool ◽  
Contact Length ◽  
Measured Temperature ◽  
Rake Face ◽  
Low Carbon ◽  
Temperature Distributions ◽  
Metallographic Method ◽  
Carbon Iron ◽  
Good Agreement

Turning experiments have been carried out on a low carbon iron using steel tools of different side rake face geometry. Temperature distributions have been determined using a recently developed metallographic method. It has been found that when using tools which have a controlled chip-tool contact length of 0.5 mm. the temperatures are ∼30 per cent lower than when using conventional, 6 deg rake tools and, as a result, tool life is longer. Theoretical equations are described which allow the calculation of the temperature distribution along the chip tool interface and the tribological conditions in this region are also considered in detail. There is good agreement between the calculated and measured temperature distributions.

Experimental Analysis and Numerical Modeling of Microwave Reheating of Cylindrically Shaped Instant Rice

2014 ◽  
Vol 10 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Daming Fan ◽  
Chunxiang Li ◽  
Yi Li ◽  
Wei Chen ◽  
Jianxin Zhao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Internal Temperature ◽  
Microwave Application ◽  
Cooked Rice ◽  
Temperature Distributions ◽  
Rice Samples ◽  
Good Agreement

Abstract The purpose of this study was to develop a numerical model to predict the temperature distribution in cylindrically shaped cooked rice samples during microwave reheating and to give impetus to a uniform microwave-heating design. Cylindrically shaped instant rice was reheated by continuous microwave application, and the sample temperature was measured to determine the internal temperature profile which resulted in a desired uniformity of temperature observed using the non-uniformity temperature evaluation. A finite difference method was used to predict the temperature distribution of the cylindrical rice during microwave reheating and applying Lambert’s law to calculate the microwave power absorption in a large sample of cylindrically shaped instant rice. In order to solve the numerical model of heat transfer, the thermal and dielectric properties of instant rice were measured with respect to temperature. Our results showed that the temperature had a significant effect on the specific heat and dielectric loss of rice, while the thermal conductivity and dielectric constant were unaffected. The numerically predicted temperature distributions were in good agreement with the measured ones of instant rice.

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