Effects of heat conduction in wall on thermoacoustic wave propagation in a gas-filled, channel subject to temperature gradient

2011 ◽  
Vol 130 (4) ◽  
pp. 2371-2371
Author(s):  
Nobumasa Sugimoto ◽  
Hiroaki Hyodo
Keyword(s):  
Wave Propagation ◽  
Heat Conduction ◽  
Temperature Gradient

Study on Radial Temperature Distribution of Aluminum Dispersed Nuclear Fuels: U3O8-Al, U3Si2-Al, and UN-Al

2018 ◽  
Vol 4 (3) ◽  
Author(s):  
Jayangani I. Ranasinghe ◽  
Ericmoore Jossou ◽  
Linu Malakkal ◽  
Barbara Szpunar ◽  
Jerzy A. Szpunar
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Steady State ◽  
Temperature Gradient ◽  
Heat Conduction Equation ◽  
Conduction Equation ◽  
Temperature Profiles ◽  
Nuclear Fuels ◽  
State Heat ◽  
Steady State Heat

The understanding of the radial distribution of temperature in a fuel pellet, under normal operation and accident conditions, is important for a safe operation of a nuclear reactor. Therefore, in this study, we have solved the steady-state heat conduction equation, to analyze the temperature profiles of a 12 mm diameter cylindrical dispersed nuclear fuels of U3O8-Al, U3Si2-Al, and UN-Al operating at 597 °C. Moreover, we have also derived the thermal conductivity correlations as a function of temperature for U3Si2, uranium mononitride (UN), and Al. To evaluate the thermal conductivity correlations of U3Si2, UN, and Al, we have used density functional theory (DFT) as incorporated in the Quantum ESPRESSO (QE) along with other codes such as Phonopy, ShengBTE, EPW (electron-phonon coupling adopting Wannier functions), and BoltzTraP (Boltzmann transport properties). However, for U3O8, we utilized the thermal conductivity correlation proposed by Pillai et al. Furthermore, the effective thermal conductivity of dispersed fuels with 5, 10, 15, 30, and 50 vol %, respectively of dispersed fuel particle densities over the temperature range of 27–627 °C was evaluated by Bruggman model. Additionally, the temperature profiles and temperature gradient profiles of the dispersed fuels were evaluated by solving the steady-state heat conduction equation by using Maple code. This study not only predicts a reduction in the centerline temperature and temperature gradient in dispersed fuels but also reveals the maximum concentration of fissile material (U3O8, U3Si2, and UN) that can be incorporated in the Al matrix without the centerline melting. Furthermore, these predictions enable the experimental scientists in selecting an appropriate dispersion fuel with a lower risk of fuel melting and fuel cracking.

Study on the Grind-Hardening of the Loader Clevis Pin

2014 ◽  
Vol 621 ◽  
pp. 140-145 ◽  
Author(s):  
Ju Dong Liu ◽  
Jie Zhen Zhuang ◽  
Zhi Long Xu
Keyword(s):  
Heat Conduction ◽  
High Temperature ◽  
Temperature Gradient ◽  
Layer Structure ◽  
Hardened Layer ◽  
Tempered Martensite ◽  
Microhardness Distribution ◽  
Hardened Zone ◽  
Grind Hardening ◽  
Arc Shape

On the basis of the cylindrical plunge grinding and intermittent axial feed grinding experiment, the grind-hardened layer structure and its property of the loader clevis pin were studied. The result shows that there are some arc shape medium/high-temperature tempered zones and some annular unhardened zone in external circumference surface, which is result of temperature gradient, induced grinding heat when circumferential feed and axial grinding heat conduction. The microstructure of hardened zone is mixture martensite, and the microstructure of tempered zone is tempered martensite and troostite. Different structure zone has same microhardness distribution regulation, but the microhardness of hardened zone can reach 640HV0.5. The loader clevis pin processed by grind-hardening meets the property request for working.

A Numerical Method for Heat Conduction Problems

1974 ◽  
Vol 96 (3) ◽  
pp. 307-312 ◽  
Author(s):  
M. J. Reiser ◽  
F. J. Appl
Keyword(s):  
Exact Solution ◽  
Heat Conduction ◽  
Steady State ◽  
Numerical Analysis ◽  
Temperature Gradient ◽  
Singular Integral ◽  
Integral Method ◽  
Two Dimensional ◽  
Convection Boundary ◽  
Steady State Heat

A singular integral method of numerical analysis for two-dimensional steady-state heat conduction problems with any combination of temperature, gradient, or convection boundary conditions is presented. Excellent agreement with the exact solution is illustrated for an example problem. The method is used to determine the solution for a fin bank with convection.

Anharmonicity Dependent Heat Conduction in One-Dimensional Lattices

2013 ◽  
Vol 209 ◽  
pp. 129-132 ◽  
Author(s):  
Shreya Shah ◽  
Tejal N. Shah ◽  
P.N. Gajjar
Keyword(s):  
Thermal Conductivity ◽  
Numerical Simulation ◽  
Heat Flux ◽  
Heat Conduction ◽  
Temperature Gradient ◽  
Temperature Profile ◽  
Chain Length ◽  
Interparticle Interactions ◽  
One Dimensional ◽  
Harmonic Chain

The temperature profile, heat flux and thermal conductivity are investigated for the chain length of 67 one-dimensional (1-D) oscillators. FPU-β and FK models are used for interparticle interactions and substrate interactions, respectively. As harmonic chain does not produce temperature gradient along the chain, it is required to introduce anharmonicity in the numerical simulation. The anharmonicity dependent temperature profile, thermal conductivity and heat flux are simulated for different strength of anharmonicity β = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1. It is concluded that heat flux obeys J = 0.3947 e0.553β with R2 = 0.9319 and thermal conductivity obeys κ = 0.0276 e0.5559β with R2 = 0.9319.

scholarly journals Theoretical Analysis of Experimental Thermoelectric Characteristics of Silicon-Based Whiskers

2019 ◽  
Vol 20 (4) ◽  
pp. 331-337
Author(s):  
Ya.S. Budzhak ◽  
А.A. Druzhinin ◽  
S.I. Nichkalo
Keyword(s):  
Magnetic Field ◽  
Heat Conduction ◽  
Solid State ◽  
Temperature Gradient ◽  
Kinetic Properties ◽  
Induction Vector ◽  
Solid State Electronics ◽  
Spatial Quantization ◽  
Silicon Based ◽  
Heat Carriers

It is shown that when a conductive crystal with electric field strength  and a temperature gradient  is placed in a magnetic field with an induction vector , processes of charge and heat carriers transport occur, and they can be described by known generalized electrical conduction and heat conduction equations. The tensors and scalar coefficients that make up these equations are the kinetic properties of crystals. They describe the nature of actual properties of crystals and have a wide pragmatic application in modern solid-state electronics. The process of spatial quantization of the spectrum and its influence on the kinetic properties of crystals is also analyzed.

Sign in / Sign up

Export Citation Format

Share Document