scholarly journals Mathematical Model of a Heating Furnace Implemented with Volumetric Fuel Combustion

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 469
Author(s):  
Miroslav Rimar ◽  
Andrii Kulikov ◽  
Marcel Fedak ◽  
Oleksandr Yeromin ◽  
Kostyantyn Sukhyy ◽  
...  
Keyword(s):  
Large Scale ◽  
Main Type ◽  
Heating Furnace ◽  
Uniform Temperature ◽  
Influence Of Temperature ◽  
Working Chamber ◽  
Furnace Gases ◽  
Uniform Temperature Field ◽  
Metal Products ◽  
Working Parameters

Heating flame furnaces are the main type of furnaces used for heating and heat treatment of metal products in metallurgy and mechanical engineering. In the working chamber of a modern heating furnace, there should be neither high-temperature nor stagnation zones. One of the methods used to provide such combustion conditions is the application of distributed (volumetric) combustion. Owing to this method, heating quality is ensured by creating a uniform temperature field and equivalent heat exchange conditions, regardless of the placement of the charge in the working chamber of the furnace. In this work, we numerically study the volumetric combustion and influences of small- and large-scale recirculation ratios of furnace gases, the influence of temperature fluctuation on the regenerator nozzle, and the working parameters at the starting phase and reverse.

The influence of temperature dependence of viscosity on stability liquid flows in a plane channel

2014 ◽  
Vol 10 ◽  
pp. 90-94 ◽  
Author(s):  
A.D. Nizamova
Keyword(s):  
Temperature Dependence ◽  
Liquid Flow ◽  
Plane Channel ◽  
Isothermal Flow ◽  
Uniform Temperature ◽  
Influence Of Temperature ◽  
Uniform Temperature Field ◽  
The Stability ◽  
Liquid Flows ◽  
Sommerfeld Equation

The influence problem of temperature dependence of viscosity on stability of liquid flow in a plane channel under non-uniform temperature field was considered. The system of two ordinary differential equations for the perturbation amplitudes of velocity and temperature was received. In the case of isothermal flow, derived system can be reduced to the Orr-Sommerfeld equation. The spectra of eigenvalues for Poiseuille flow with different temperature dependence of viscosity were numerical studied. It is shown that temperature dependence of viscosity has an influence on the stability of the liquid flow.

scholarly journals Influence of temperature on the larval development of the edible crab, Cancer pagurus

2009 ◽  
Vol 89 (4) ◽  
pp. 753-759 ◽  
Author(s):  
Monika Weiss ◽  
Sven Thatje ◽  
Olaf Heilmayer ◽  
Klaus Anger ◽  
Thomas Brey ◽  
...  
Keyword(s):  
Larval Development ◽  
Body Mass ◽  
Large Scale ◽  
Citrate Synthase ◽  
C:N Ratio ◽  
Intraspecific Variability ◽  
Larval Body ◽  
Influence Of Temperature ◽  
Cancer Pagurus ◽  
Influence Of Temperature On

The influence of temperature on larval survival and development was studied in the edible crab, Cancer pagurus, from a population off the island of Helgoland, North Sea. In rearing experiments conducted at six different temperatures (6°, 10°, 14°, 15°, 18° and 24°C), zoeal development was only completed at 14° and 15°C. Instar duration of the Zoea I was negatively correlated with temperature. A model relating larval body mass to temperature and developmental time suggests that successful larval development is possible within a narrow temperature range (14° ± 3°C) only. This temperature optimum coincides with the highest citrate synthase activity found at 14°C. A comparison for intraspecific variability among freshly hatched zoeae from different females (CW 13–17 cm, N = 8) revealed that both body mass and elemental composition varied significantly. Initial larval dry weight ranged from 12.1 to 17.9 μg/individual, the carbon content from 4.6 to 5.8 μg/individual, nitrogen from 1.1 to 1.3 μg/individual, and the C:N ratio from 4.1 to 4.4. A narrow larval temperature tolerance range of C. pagurus as well as the indication of intraspecific variability in female energy allocation into eggs may indicate a potential vulnerability of this species to climate change. Large-scale studies on the ecological and physiological resilience potential of this commercially fished predator are needed.

Non-uniform temperature distribution of the main reflector of a large radio telescope under solar radiation

2021 ◽  
Vol 21 (11) ◽  
pp. 293
Author(s):  
Shan-Xiang Wei ◽  
De-Qing Kong ◽  
Qi-Ming Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Radio Telescope ◽  
Thermal Imaging ◽  
Uniform Temperature ◽  
Large Radio Telescope ◽  
Uniform Temperature Distribution ◽  
Uniform Temperature Field ◽  
Main Reflector

Abstract The non-uniform temperature distribution of the main reflector of a large radio telescope may cause serious deformation of the main reflector, which will dramatically reduce the aperture efficiency of a radio telescope. To study the non-uniform temperature field of the main reflector of a large radio telescope, numerical calculations including thermal environment factors, the coefficients on convection and radiation, and the shadow boundary of the main reflector are first discussed. In addition, the shadow coverage and the non-uniform temperature field of the main reflector of a 70-m radio telescope under solar radiation are simulated by finite element analysis. The simulation results show that the temperature distribution of the main reflector under solar radiation is very uneven, and the maximum of the root mean square temperature is 12.3°C. To verify the simulation results, an optical camera and a thermal imaging camera are used to measure the shadow coverage and the non-uniform temperature distribution of the main reflector on a clear day. At the same time, some temperature sensors are used to measure the temperature at some points close to the main reflector on the backup structure. It has been verified that the simulation and measurement results of the shadow coverage on the main reflector are in good agreement, and the cosine similarity between the simulation and the measurement is above 90%. Despite the inevitable thermal imaging errors caused by large viewing angles, the simulated temperature field is similar to the measured temperature distribution of the main reflector to a large extent. The temperature trend measured at the test points on the backup structure close to the main reflector without direct solar radiation is consistent with the simulated temperature trend of the corresponding points on the main reflector with the solar radiation. It is credible to calculate the temperature field of the main reflector through the finite element method. This work can provide valuable references for studying the thermal deformation and the surface accuracy of the main reflector of a large radio telescope.

scholarly journals Polarizing effect in natural polymer cellulose

2019 ◽  
pp. 45-46
Author(s):  
N. N. Matveev ◽  
V. V. Saushkin ◽  
N. Yu. Evsikova ◽  
N. S. Kamalova ◽  
V. I. Lisitsyn
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Natural Polymer ◽  
Uniform Temperature ◽  
Polarization Mechanism ◽  
Uniform Temperature Field ◽  
First Time

For the first time, a method based on the registration of polarization and depolarization currents arising in wood in a non-uniform temperature field was used to study the properties of cellulose. The purpose of the method used is to record the relaxation of bound charges with a change in the temperature of the sample under study. It is shown that the detected low-temperature transitions have a crystal-crystal polarization mechanism, and the natural polymer cellulose is an active dielectric.

Non-uniform temperature field and effects of Shanghai 65 m radio telescope

2014 ◽  
Vol 22 (4) ◽  
pp. 970-978 ◽  
Author(s):  
钱宏亮 QIAN Hong-liang ◽  
柳叶 LIU Ye ◽  
范峰 FAN Feng ◽  
金晓飞 JIN Xiao-fei
Keyword(s):  
Temperature Field ◽  
Radio Telescope ◽  
Uniform Temperature ◽  
Uniform Temperature Field

The Composite Tool Design Technologies of Aircraft Composite Parts in Autoclave Forming

2012 ◽  
Vol 426 ◽  
pp. 330-334 ◽  
Author(s):  
Ying Guang Li ◽  
C.Y. Fu ◽  
D.S. Li ◽  
S.M. Wan
Keyword(s):  
Temperature Field ◽  
Fiber Reinforced Composites ◽  
Field Analysis ◽  
Reinforced Composites ◽  
Uniform Temperature ◽  
Composite Component ◽  
Cure Process ◽  
Design Flexibility ◽  
Composite Tool ◽  
Uniform Temperature Field

Aiming at the problems of composites of anisotropic, poor in dimensional and uneven temperature field in the designing of composite tool in autoclave, the techniques of designing the composite tool of aircraft components were constructed, involving in the following aspects: Taking advantage of design flexibility of composites, the thermal expansion coefficient between the moulding board and composite components matched. By analyzing the cure process curve of fiber-reinforced composites, the result that the crisis point without stress between component and tool, which the shape of composite component decided was concluded. By the temperature field analysis, and contrasted with the experimental results, the maximum difference was 4.95°C，after analysis, optimized the structure of the tool, obtaining the relatively uniform temperature field of the board.

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