scholarly journals Temperature Problem

2020 ◽  
Author(s):  
Keyword(s):  
Temperature Problem

Use of Asymptotic Methods in the Temperature Problem on Filtration of Gassed Oil in a Pool

2004 ◽  
Vol 77 (1) ◽  
pp. 62-83
Author(s):  
A. I. Filippov ◽  
S. A. Filippov
Keyword(s):  
Asymptotic Methods ◽  
Temperature Problem

Development of a Mathematical Model for a Workpiece Heating and Cooling in a Protective Medium while Treatment under Pressure

2021 ◽  
Vol 410 ◽  
pp. 115-122
Author(s):  
Victoria V. Devyatiarova ◽  
Eugenia E. Balakhnina ◽  
Lilya M. Valeeva
Keyword(s):  
Mathematical Model ◽  
Cross Section ◽  
Arbitrary Shape ◽  
Thermal Conductivity Coefficient ◽  
Regression Equations ◽  
Heating And Cooling ◽  
Temperature Problem ◽  
Protective Medium ◽  
Computer Calculations ◽  
The Mathematical Model

The paper reviews and develops the mathematical model of plastic flow during the hot-forming processes. A flat non-stationary temperature problem for a cross-section of a long solid (rolled product) of arbitrary shape with different heat transfer conditions along the perimeter of the cross-section was considered. Equations for calculation of the thermal conductivity coefficient and heat capacity of tungsten billets were obtained in the temperature range of 700 - 1500°C, based on the literature data. Analytical dependences in form of regression equations were obtained, allowing for computer calculations of physical specifications of 11x11 mm VA grade tungsten billets in form of temperature functions with accuracy sufficient for practical calculations.

A Method of Solving Three Temperature Problem of Turbine With Adiabatic Wall Temperature

2021 ◽  
Author(s):  
Zeyu Wu ◽  
Xiang Luo ◽  
Jianqin Zhu ◽  
Zhe Zhang ◽  
Jiahua Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Reynolds Number ◽  
Wall Temperature ◽  
Reference Temperature ◽  
Inlet Temperature ◽  
Adiabatic Wall ◽  
Rotating Cavity ◽  
Temperature Problem ◽  
Turbulence Parameters

Abstract The aeroengine turbine cavity with pre-swirl structure makes the turbine component obtain better cooling effect, but the complex design of inlet and outlet makes it difficult to determine the heat transfer reference temperature of turbine disk. For the pre-swirl structure with two air intakes, the driving temperature difference of heat transfer between disk and cooling air cannot be determined either in theory or in test, which is usually called three-temperature problem. In this paper, the three-temperature problem of a rotating cavity with two cross inlets are studied by means of experiment and numerical simulation. By substituting the adiabatic wall temperature for the inlet temperature and summarizing its variation law, the problem of selecting the reference temperature of the multi-inlet cavity can be solved. The results show that the distribution of the adiabatic wall temperature is divided into the high jet area and the low inflow area, which are mainly affected by the turbulence parameters λT, the rotating Reynolds number Reω, the high inlet temperature Tf,H* and the low radius inlet temperature Tf,L* of the inflow, while the partition position rd can be considered only related to the turbulence parameters λT and the rotating Reynolds number Reω of the inflow. In this paper, based on the analysis of the numerical simulation results, the calculation formulas of the partition position rd and the adiabatic wall temperature distribution are obtained. The results show that the method of experiment combined with adiabatic wall temperature zone simulation can effectively solve the three-temperature problem of rotating cavity.

scholarly journals On Two-Temperature Problem for Harmonic Crystals

2004 ◽  
Vol 114 (3/4) ◽  
pp. 1035-1083 ◽  
Author(s):  
T. V. Dudnikova ◽  
A. I. Komech ◽  
N. J. Mauser
Keyword(s):  
Temperature Problem ◽  
Harmonic Crystals ◽  
Two Temperature

Heat Transfer in Cylindrical Pipes With Fully Established Turbulent Flow and Exposed to a Uniform Temperature Environment

1966 ◽  
Vol 88 (3) ◽  
pp. 305-311 ◽  
Author(s):  
J. W. Goresh
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Heat Equation ◽  
Jacobi Polynomials ◽  
Heat Losses ◽  
Uniform Temperature ◽  
Uniform Wall Temperature ◽  
Temperature Problem ◽  
Temperature Environment ◽  
Uniform Wall

The problem considered is that of determining the heat losses from a gas flowing turbulently in a poorly insulated pipe where the heat lost from the outer surface is by free convection and radiation. The approach employed in solving the heat equation is analogous to that first introduced by Latzko for the solution of the uniform wall temperature problem. Later, in 1957, Fettis obtained a solution to the same problem in terms of Jacobi polynomials. A method for coupling the inner convection with the environment is given in the later portion of the paper. The results obtained for a numerical case are also presented.

Influence of a Leaking Gap Downstream of the Injection Holes on Film Cooling Performance

1996 ◽  
Author(s):  
Y. Yu ◽  
M. K. Chyu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Cooling System ◽  
Convective Transport ◽  
Hole Injection ◽  
Thermochromic Liquid Crystal ◽  
Cooling Performance ◽  
Temperature Problem

This study investigated a practical but never exploited issue concerning the influence of flow leakage through a gap downstream on the film cooling performance with a row of discrete-hole injection. A heat transfer system as such can be categorized as either a three-temperature or a four-temperature problem, depending on the direction of leakage through the gap. To fully characterize a three-temperature based film-cooling system requires knowledge of both local film effectiveness and heat transfer coefficient. A second film effectiveness is necessary for characterizing a four-temperature problem. All these variables can be experimentally determined, based on the transient method of thermochromic liquid crystal imaging. Although the overall convective transport in the region is expected to be dependent on the blowing ratios of the coolants, the mass flow ratio of the two injectants, and the geometry, the current results indicated that the extent of flow injection or extraction through the gap has significant effects on the film effectiveness and less on the heat transfer coefficient which is primarily dominated by the geometric disturbance of gap presence.

The Temperature Problem at the Bone-acrylic Cement Interface of the Total Hip Replacement

1976 ◽  
Vol &NA; (121) ◽  
pp. 95???98 ◽  
Author(s):  
JOSEPH A. DIPISA ◽  
GEORGE S. SIH ◽  
ARNOLD T. BERMAN
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Cement Interface ◽  
Acrylic Cement ◽  
Total Hip ◽  
Temperature Problem

Conjugate Heat Transfer Within a Heterogeneous Hierarchical Structure

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
Ivan Catton
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Heat Exchangers ◽  
Transport Equations ◽  
Complex Data ◽  
Structural Morphology ◽  
Tube Heat Exchanger ◽  
Temperature Problem ◽  
Finned Tube Heat Exchanger ◽  
Two Temperature

Optimization of heat exchangers (HE), compact heat exchangers (CHE) and microheat exchangers, by design of their basic structures is the focus of this work. Consistant models are developed to describe transport phenomena in a porous medium that take into account the scales and other characteristics of the medium morphology. Equation sets allowing for turbulence and two temperature or two concentration diffusion are obtained for nonisotropic porous media with interface exchange. The equations differ from known equations and were developed using a rigorous averaging technique, hierarchical modeling methodology, and fully turbulent models with Reynolds stresses and fluxes in the space of every pore. The transport equations are shown to have additional integral and differential terms. The description of the structural morphology determines the importance of these terms and the range of application of the closure schemes. A natural way to transfer from transport equations in a porous media with integral terms to differential equations with coefficients that could be experimentally or numerically evaluated and determined is described. The relationship between computational fluid dynamics, experiment and closure needed for the volume averaged equations is discussed. Mathematical models for modeling momentum and heat transport based on well established averaging theorems are developed. Use of a “porous media” length scale is shown to be very beneficial in collapsing complex data onto a single curve yielding simple heat transfer and friction factor correlations. The general transport equations developed for a single phase fluid in a heat exchange medium have many more integral and differential terms than the homogenized or classical continuum mechanics equations. Once these terms are dealt with by closure, the resulting equation set is relatively simple and their solution is obtained using simple numerical methods quickly enough for multiple parameter optimization using design of experiment or genetic algorithms. Current efforts to significantly improve the performance of an HE for electronic cooling, a two temperature problem, and of a finned tube heat exchanger, a three temperature problem, are described.

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