scholarly journals Numerical and experimental study of pyrophoric activated metal Mg surface combustion characteristics

2018 ◽  
Vol 5 (5) ◽  
pp. 172064
Author(s):  
Hesong Huang ◽  
Zhongxiang Tong ◽  
Chaozhe Wang ◽  
Biao Wang
Keyword(s):  
Temperature Distribution ◽  
Heat Balance ◽  
High Speed ◽  
Difficult Problem ◽  
Combustion Mechanism ◽  
Thermal Imager ◽  
Balance Equations ◽  
Adiabatic Wall ◽  
The Heat Balance ◽  
Infrared Thermal Imager

The combustion of multi-hole pyrophoric activated metal is solid combustion and the combustion mechanism is quite complex, which is a difficult problem to be solved. Once the pyrophoric activated metal is exposed to air, the oxygen diffuses to the interior of the activated metal within plenty of holes and reacts with it, which enlarges the contact area with oxygen. Consequently, the whole combustion is vigorous and the temperature rises rapidly. To study the combustion mechanism of the chaff, the surface heat balance equation is established in this work by taking Mg as the activated metal. To solve this equation, the chaff adiabatic wall temperature distribution is computed by computational fluid dynamics in the presence of high-speed airflow. Then, the chaff surface temperature distribution is obtained by solving the heat balance equations. Finally, numerical and experimental results obtained via an infrared thermal imager are compared to demonstrate the effectiveness of the established equation.

Research on On-Line Anti-Icing Technology for Carenary along Electrified Railway

2013 ◽  
Vol 676 ◽  
pp. 321-324
Author(s):  
Lei Guo ◽  
Qun Zhan Li
Keyword(s):  
Simulation Model ◽  
Heat Balance ◽  
Normal Operation ◽  
Balance Equations ◽  
Model Based ◽  
Static Var Generator ◽  
On Line ◽  
Electrified Railway ◽  
The Heat Balance

Accidents of icing on catenary have great impacts on normal operation of trains. An on-line anti-icing technology used static var generator (SVG) for catenary was proposed, which can prevent icing formation without interrupting trains normal operation. The heat balance equations for catenary were solved, whose results were compared with data provided by TB/T 3111 and testing show the equation was correct. The simulation model based on Matlab was bulit , whose results and analysis show the correctness of the method.

Calculation of Hourly Output of a Solar Still

1993 ◽  
Vol 115 (4) ◽  
pp. 231-236 ◽  
Author(s):  
V. B. Sharma ◽  
S. C. Mullick
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Balance ◽  
Solar Still ◽  
Balance Equations ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Hourly Output ◽  
The Heat Balance

An approximate method for calculation of the hourly output of a solar still over a 24-hour cycle has been studied. The hourly performance of a solar still is predicted given the values of the insolation, ambient temperature, wind heat-transfer coefficient, water depth, and the heat-transfer coefficient through base and sides. The proposed method does not require graphical constructions and does not assume constant heat-transfer coefficients as in the previous methods. The possibility of using the values of the heat-transfer coefficients for the preceding time interval in the heat balance equations is examined. In fact, two variants of the basic method of calculation are examined. The hourly rate of evaporation is obtained. The results are compared to those obtained by numerical solution of the complete set of heat balance equations. The errors from the approximate method in prediction of the 24-hour output are within ±1.5 percent of the values from the numerical solution using the heat balance equations. The range of variables covered is 5 to 15 cms in water depth, 0 to 3 W/m2K in a heat-transfer coefficient through base and sides, and 5 to 40 W/m2K in a wind heat-transfer coefficient.

Modeling of Droplet Dynamic and Thermal Behavior during Gas Atomization Process

2011 ◽  
Vol 672 ◽  
pp. 80-83
Author(s):  
Marius Bodea ◽  
Radu Mureşan ◽  
Virgiliu Călin Prică
Keyword(s):  
Heat Balance ◽  
Temperature History ◽  
Gas Atomization ◽  
Fragmentation Mechanism ◽  
Balance Equations ◽  
Atomization Process ◽  
Breakup Mechanism ◽  
Secondary Breakup ◽  
Physical Phenomena ◽  
The Heat Balance

The paper is focused on the physical phenomena that occurs during gas atomization process, like fragmentation mechanism of the molten stream, the secondary breakup mechanism, droplets velocities and particles temperature history. The modeling of droplet dynamic and thermal history was achieved by using a software program realized by authors, called MetLAB, using the heat balance equations between the cooling gas and the molten metal droplets.

scholarly journals Experimental study of the adiabatic wall temperature of a cylinder in a supersonic cross flow

2021 ◽  
Vol 2039 (1) ◽  
pp. 012029
Author(s):  
S S Popovich ◽  
N A Kiselev ◽  
A G Zditovets ◽  
Y A Vinogradov
Keyword(s):  
Experimental Study ◽  
Wall Temperature ◽  
High Speed ◽  
Cross Flow ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
State University ◽  
Adiabatic Wall ◽  
Speed Flow ◽  
Total Temperature

Abstract The results of an experimental study of the adiabatic wall temperature for a supersonic air flow across the cylinder are presented. The temperature was measured contactlessly using an InfraTEC ImageIR 8855 thermal imager through a ZnSe infrared illuminator. The freestream Mach number was 3.0, input flow total temperature was 295 K, and the total pressure 615 kPa. The Reynolds number calculated from the cylinder diameter (30 mm) was about 106. It is shown that it is possible in principle to determine the high-speed flow total temperature by defining the maximum temperature of a cylindrical probe at the front critical point. Thermograms of the wall temperature distribution along the profile of the cylinder were obtained. The research was performed at the experimental facilities of the Institute of Mechanics of Lomonosov Moscow State University.

An Approximate Analysis of the Temperature Conditions in a Journal Bearing. Part II: Application

1984 ◽  
Vol 106 (2) ◽  
pp. 237-244 ◽  
Author(s):  
J. W. Lund ◽  
J. Tonnesen
Keyword(s):  
Temperature Distribution ◽  
Heat Balance ◽  
Journal Bearing ◽  
Pressure Profile ◽  
Design Parameters ◽  
Experimental Measurements ◽  
Approximate Analysis ◽  
Bearing Sleeve ◽  
The Heat Balance ◽  
Bearing Part

To test the validity of the theory, described in Part I of this investigation, calculations are performed for a cylindrical, two-axial groove journal bearing over a range of loads and speeds. The results give the temperature distribution in the lubricant film and in the bearing sleeve, the journal surface temperature, the heat balance for the bearing, the journal center eccentricity, and the film pressure profile. The calculated results are compared with experimental measurements, and although significant discrepancies are observed, the overall agreement is satisfactory, considering the usual tolerance effects and the uncertainties in defining some of the design parameters

scholarly journals Numerical study of the efficiency of integrating phase change material into a clay-straw wall in the Drâa-Tafilalet region (Errachidia Province)

2021 ◽  
Vol 297 ◽  
pp. 01007
Author(s):  
Zaineb Ben Zaid ◽  
Amine Tilioua ◽  
Omar Ansari ◽  
Ibtissam Lamaamar ◽  
Moulay Ahmed Hamdi Alaoui
Keyword(s):  
Phase Change ◽  
Heat Balance ◽  
Heat Flux Density ◽  
Phase Change Materials ◽  
Numerical Study ◽  
Climatic Conditions ◽  
Balance Equations ◽  
Different Types ◽  
Change Material ◽  
The Heat Balance

The objective of this study is to evaluate the thermal performance of clay-straw walls of buildings integrating phase change materials (PCM). The influence of integrating different types of PCM in the envelope has been studied numerically in several studies. The optimal wall thickness with PCM integrated suitable for the climatic conditions of Errachidia has been studied. The heat balance equations for the different wall configurations are formulated and solved numerically under the same climatic conditions. The results obtained show that the integration of PCM in the clay-straw wall instead of the cement wall increases the heat flux density as a function of time by up to 80 % based on the thermal properties of the PCM and the environmental conditions of the study.

scholarly journals HEAT BALANCE RESEARCH OF 3MW MARINE WIND TURBINE'S ENGINE ROOM

2012 ◽  
Vol 19 ◽  
pp. 362-373
Author(s):  
NA KANG ◽  
YANLONG JIANG ◽  
NIANYONG ZHOU ◽  
HONG SHI ◽  
ZHILI LIU ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Wind Turbine ◽  
Heat Balance ◽  
Heat Load ◽  
Cooling System ◽  
Turbine Cooling ◽  
Engine Room ◽  
Wind Turbine System ◽  
Volume Method ◽  
The Heat Balance

The increment of heat load in Wind Turbine's engine room could cause the system shut down. In this paper the heat balance of Wind Turbine's engine room is investigated according to the structure of the engine room, environmental operating requirements as well as heat-dissipating of different components of a 3MW Wind Turbine System. The heat load of the engine room is analyzed and the physical model is developed based on finite volume method. After that, the temperature distribution of the cabin is obtained under different conditions with/without the jet unit. The temperature distribution in engine compartments with different number and the arrangement of jet units is compared in this paper. Based on the analysis, the cabin cooling design is carried out to achieve the purpose of stopping heat gathering and keeping heat balance of the cabin. This work puts forward the heat balance maintenance and completes the corresponding research, which could be helpful for the optimization of large-capacity Wind Turbine cooling system.

scholarly journals Logistic Heat Integral Methods for the One-Phase Stefan Problem

2011 ◽  
Vol 2011 ◽  
pp. 1-13
Author(s):  
O. P. Layeni ◽  
A. M. Adegoke
Keyword(s):  
Temperature Distribution ◽  
Boundary Conditions ◽  
Stefan Problem ◽  
Heat Balance ◽  
Time Dependent ◽  
Integral Methods ◽  
The One ◽  
The Heat Balance ◽  
Moving Front

Logistic versions of the heat balance integral and refined integral methods are introduced. A benchmark with a one-phase Stefan problem under constant and time-dependent boundary conditions shows remarkable accuracy at estimating temperature distribution and position of the moving front.

Experimental Research on Cutting Temperature of AISI 1045 in High Speed Milling Process

2014 ◽  
Vol 893 ◽  
pp. 621-624
Author(s):  
Yong Feng ◽  
Mu Lan Wang ◽  
Bao Sheng Wang ◽  
Jun Ming Hou
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Experimental System ◽  
Milling Process ◽  
Thermal Imager ◽  
High Speed Milling ◽  
High Speed Cutting ◽  
Aisi 1045

The aim of this paper is to investigate the time dependence distribution of workpiece cutting temperature in milling process. An experimental system used to achieve a measurement of cutting temperature in high speed milling is designed by use of the thermocouple and infrared thermal imager. The general regularity of temperature distribution is concluded, and the influence of the process variables such as cutting speed, cutting depth, etc. on the temperature distribution was investigated in detail. All the experiment results can be effective used to develop a new non-contact soft-sensing method for high speed cutting temperature prediction.

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