scholarly journals Ablation behavior studies of charring materials with different thickness and heat flux intensity

2021 ◽  
Vol 23 ◽  
pp. 100814
Author(s):  
Jie Xiao ◽  
Oisik Das ◽  
Rhoda Afriyie Mensah ◽  
Lin Jiang ◽  
Qiang Xu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Intensity ◽  
Heat Flux Intensity ◽  
Different Thickness

scholarly journals Non-Fourier Heat Conduction of a Functionally Graded Cylinder Containing a Cylindrical Crack

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Jiawei Fu ◽  
Keqiang Hu ◽  
Linfang Qian ◽  
Zengtao Chen
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Intensity Factor ◽  
Functionally Graded ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Flux Intensity ◽  
Cylindrical Crack ◽  
Heat Flux Intensity ◽  
Fourier Heat Conduction

The present work investigates the problem of a cylindrical crack in a functionally graded cylinder under thermal impact by using the non-Fourier heat conduction model. The theoretical derivation is performed by methods of Fourier integral transform, Laplace transform, and Cauchy singular integral equation. The concept of heat flux intensity factor is introduced to investigate the heat concentration degree around the crack tip quantitatively. The temperature field and the heat flux intensity factor in the time domain are obtained by transforming the corresponding quantities from the Laplace domain numerically. The effects of heat conduction model, functionally graded parameter, and thermal resistance of crack on the temperature distribution and heat flux intensity factor are studied. This work is beneficial for the thermal design of functionally graded cylinder containing a cylindrical crack.

scholarly journals Heat Concentration around a Cylindrical Interface Crack in a Composite Tube

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
J. W. Fu ◽  
L. F. Qian
Keyword(s):  
Heat Flux ◽  
Intensity Factor ◽  
Interface Crack ◽  
Composite Structures ◽  
Superposition Method ◽  
Liner Material ◽  
Composite Tube ◽  
Cylindrical Interface ◽  
Flux Intensity ◽  
Heat Flux Intensity

Cracks always form at the interface of discrepant materials in composite structures, which influence thermal performances of the structures under transient thermal loadings remarkably. The heat concentration around a cylindrical interface crack in a bilayered composite tube has not been resolved in literature and thus is investigated in this paper based on the singular integral equation method. The time variable in the two-dimensional temperature governing equation, derived from the non-Fourier theory, is eliminated using the Laplace transformation technique and then solved exactly in the Laplacian domain by the employment of a superposition method. The heat concentration degree caused by the interface crack is judged quantitatively with the employment of heat flux intensity factor. After restoring the results in the time domain using a numerical Laplace inversion technique, the effects of thermal resistance of crack, liner material, and crack length on the results are analyzed with a numerical case study. It is found that heat flux intensity factor is material-dependent, and steel is the best liner material among the three potential materials used for sustaining transiently high temperature loadings.

Efficiency of Water Curtains

2014 ◽  
Vol 1057 ◽  
pp. 147-154 ◽  
Author(s):  
Zdeněk Kadlec ◽  
Miloš Kvarčák
Keyword(s):  
Heat Flux ◽  
Theoretical Calculations ◽  
Radiant Heat ◽  
Radiant Heat Flux ◽  
Water Curtain ◽  
Flux Intensity ◽  
Heat Flux Intensity ◽  
Fire Spreading

It is possible to use a water curtain to preclude a house fire spreading. Water curtains are designed pursuant to theoretical calculations. Experiments were prepared and realised with a goal to determine the radiant heat flux intensity reduction of fire passing through a water curtain in VŠB, TU – Ostrava.

scholarly journals Investigation of heat flux intensity during composting of organic wastes

2020 ◽  
Vol 548 ◽  
pp. 022021
Author(s):  
G K Ivakhnyuk ◽  
I L Skripnik ◽  
Yu G Ksenofontov ◽  
T T Kaverzneva ◽  
A V Basharichev
Keyword(s):  
Heat Flux ◽  
Organic Wastes ◽  
Flux Intensity ◽  
Heat Flux Intensity

Study on transient heat flux intensity factor with interaction integral

2019 ◽  
Vol 146 ◽  
pp. 106014
Author(s):  
Huachao Deng ◽  
Bo Yan ◽  
Honghong Su ◽  
Xiaomin Zhang ◽  
Xin Lv
Keyword(s):  
Heat Flux ◽  
Intensity Factor ◽  
Interaction Integral ◽  
Flux Intensity ◽  
Heat Flux Intensity ◽  
Transient Heat Flux

Numerical Investigation of Transitional Characteristics for Natural-Convection Flow in Open-Ended Inclined Channel Heated From Below

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
D. Talukdar ◽  
C. G. Li ◽  
R. Kurose ◽  
M. Tsubokura
Keyword(s):  
Heat Flux ◽  
Nusselt Number ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Wall Temperature ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Inclined Channel ◽  
Flux Intensity ◽  
Heat Flux Intensity

Abstract This report presents an investigation of the characteristics for transitional natural-convection flow in an open-ended inclined channel heated from below in the air under uniform heat flux intensity and non-Boussinesq condition. The investigated range of modified Rayleigh number and inclination is from 5.93 × 106  to 1.45 × 109  and 30–90 deg to the horizontal, respectively. Fine-resolution implicit large Eddy simulation is performed to solve the compressible governing equations using the modified preconditioned all-speed Roe scheme, hybrid boundary condition, and dual-time-stepping technique. The Nusselt number based on the maximum wall-temperature differs significantly while based on averaged wall-temperature is closer to the previously proposed laminar correlations. Transition is found to be pronounced at a lower angle of inclination (30 deg) for the considered heat flux intensity. The absolute magnitude of the critical length for the start and end of the transition when converted to nondimensional parameters is found to be higher compared to similar data for natural convection flow over a flat plate in water but the ratio of the end to start of the transition is found to be comparable. Single-roll longitudinal vortices periodically placed in spanwise direction exists in the transition region whose wavelength is found to be higher than those reported for channel flow under the isothermal condition and flow over a flat plate in water. Correlations for Nusselt number, critical aspect ratio, and vortex wavelength to the modified Rayleigh number are presented.

Static and Dynamic Response of a Cu-Ni Thin Film Heat Flux Sensor

2014 ◽  
Vol 960-961 ◽  
pp. 304-307
Author(s):  
Shuo Wu ◽  
Fang Ye ◽  
Hang Guo ◽  
Chong Fang Ma
Keyword(s):  
Thin Film ◽  
Heat Flux ◽  
Polyimide Film ◽  
Heat Flux Sensor ◽  
Coating Technology ◽  
State Tests ◽  
Static And Dynamic Tests ◽  
Film Substrate ◽  
Different Thickness ◽  
Flux Sensor

A Cu-Ni thin film heat flux sensor had been fabricated on a 0.05mm thick polyimide film substrate by vacuum coating technology. The overall dimension of the sensor was 8 mm long and 4 mm wide. A thermopile and a thermocouple were arranged on the substrate to measure both heat flux and surface temperature. The thermopile had 18 thermocouple junctions which formed 9 pairs of differential thermocouples and were covered by two different thickness of thermal resistance layers. This research carried out static and dynamic tests of the thin film heat flux sensor. Seebeck coefficient of thermocouple is 19.3761μV/(°C). Sensitivity of the thermopile is 0.010121μV/(W/m2). Steady-state tests of the thermopile and the thermocouple were taken separately. Time constant of the thermocouple is about 0.26s, which is faster than the thermopile of 1.57s.

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