Research on the Temperature Distribution near the Surface of Long-Shaft Heavy Forging

2012 ◽  
Vol 452-453 ◽  
pp. 1470-1474
Author(s):  
Qin Xiang Xia ◽  
Bao Hua Cao ◽  
Zhe Lin Li ◽  
Wei Qi Zong ◽  
He Qing Xie
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Cross Section ◽  
Measurement Technique ◽  
Theoretical Basis ◽  
Air Cooling ◽  
Two Dimensional ◽  
Ansys Software ◽  
Cooling Process ◽  
Image Measurement

The precise edges of forging should be extracted from the image when measuring the dimensions of high temperature forging based on the non-contact image measurement technique. It is difficult to distinguish the forging boundary precisely due to the continuous variation of the air temperature near the forging. The two-dimensional simplified cross-section models, including the squaring, chamfering and rounding models, were established by the symmetrical modeling method. The air-cooling process from 1200°C to 800°C of high temperature long-shaft heavy forging was simulated based on ANSYS software. The variation regularities of temperature with the distance and time were obtained, which provides a theoretical basis to determine the edges of high temperature objects in non-contact measurement.

Research on Influencing Factors of Methane/Air Combustion in the Ring Porous Medium Burner

2011 ◽  
Vol 130-134 ◽  
pp. 1734-1738 ◽  
Author(s):  
Jiang Rong Xu ◽  
Jian Ming Zhao ◽  
Shan Shan Xu ◽  
Guan Qing Wang
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
High Temperature ◽  
Temperature Distribution ◽  
Influencing Factors ◽  
Hot Spots ◽  
Theoretical Basis ◽  
Asymmetric Structure ◽  
Mixed Gas ◽  
Simulation Results

In this paper, we focuses on combustion characteristics of the mixed gas of methane/air in the ring porous medium burner using numerical simulating method. The influencing factors of combustion, such as different methane/air ratio, the velocity of flow and heat loss of internal and external wall, are discussed, and it is shown that the ring porous medium burners have some advantages different from straight or rectangular porous media burners. Due to annular asymmetric structure, the temperature distribution of ring porous media burners are more uniform, and are no unfavorable phenomena such as the local high temperature and the hot spots. The simulation results for annular porous medium provides important theoretical basis for the development of new porous medium burners.

Experimental Research on the Characteristics of Thermal Bow in an Aeroengine HP Spool

2020 ◽  
Author(s):  
Xiangyu Yu ◽  
Zhansheng Liu ◽  
Zhaohua Zhou ◽  
Jigang Feng ◽  
Peng He
Keyword(s):  
Temperature Distribution ◽  
Cross Section ◽  
Temperature Difference ◽  
Vibration Amplitude ◽  
Structural Deformation ◽  
Dynamic Experiment ◽  
Cooling Process ◽  
Hot Air ◽  
Dynamic Experiments ◽  
Static Experiment

Abstract During the cooling process after shut down for aeroengines, internal hot air rises and cold air drops due to natural convection, which makes uneven temperature distribution in the casing and creates temperature difference in radial and axial directions, causing uneven deformation of rotor. Once aeroengine starts after a little time of cooling, thermal bow forms more easily, causing excessive vibration. In some cases, the thermal bow can be so severe that the engine will be unable to start. Based on the rotor for one certain type of aeroengine, the paper describes an experiment of thermal bow failure, which is divided into a static one and a dynamic one, both having simulated the uneven temperature field. Firstly, the static experiment measures temperature difference and deformation of rotor in different temperature environments and dissimilar cold blowing conditions. Results show temperature difference of each cross section increases with the growth of casing temperature. And cold blowing can quickly and effectively eliminate uneven temperature distribution and structural deformation. Secondly, the dynamic experiment produces the results that the vibration amplitude increases obviously when rotating frequency approaches critical speeds (2365r/min and 2892r/min). As the cooling time increases, the amplitude decreases until normal, which is the most important feature different from that in failure of initial mass imbalance. Thermal bow mainly influences the fundamental frequency vibration. Cold blowing can quickly and effectively reduce vibration amplitude. The conclusions obtained from the dynamic experiments are consistent with the known regulations from engineering experience.

Two-Dimensional Spectroscopic Observation of Nonluminous Flames in a Regenerative Industrial Furnace Using Coal Gas

2004 ◽  
Vol 126 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Y. Hino ◽  
S. Sugiyama ◽  
Y. Suzukawa ◽  
I. Mori ◽  
N. Konishi ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Emission Intensity ◽  
Premixed Flame ◽  
Band Pass Filter ◽  
Two Dimensional ◽  
Gas Temperature ◽  
Pass Filter ◽  
Soot Particles ◽  
Coal Gas

Thermal and chemical characteristics of the flames obtained from an industrial size regenerative combustion furnace have been obtained spectroscopically. The combustion characteristics of diffusion or premixed flames in the regenerative high-temperature air combustion facility have been examined using coal gas as the fuel. The fuel gas composition consisted of H2, hydrocarbon, CO, and N2. Monochromatic images of the flames have been observed in the emission mode using a CCD camera fitted with an optical band pass filter at the desired wavelength. The two-dimensional temperature distribution in the furnace has been determined using the two-line method by utilizing the Swan emission bands from within the flame. The emission intensity profiles of NO, as well as OH and CH radicals have also been observed spectroscopically. The results showed quite uniform two-dimensional temperature distribution and emission intensity of OH and CH radical species for the diffusion flame case as compared to the premixed case using high-temperature combustion air. The premixed flame case showed high local values and large fluctuations in the combustion zone for both emission intensity and temperature distribution. The temperature distribution of soot particles in the premixed flame was also determined using the two-color optical method. The results showed high local value of temperature, similar to that found for the gas temperature using signatures for C2 species at two different wavelengths. In contrast the distribution of temperature for soot particles was different. The location of the maximum soot temperature shifted to downstream positions of the flame as compared to the maximum gas temperature regions measured from the C2 species. The experimental results are discussed in conjunction with those obtained from the heat simulation analyses.

Heat Transfer Coefficient Prediction by FEM in the Hot Strip Rolling

2011 ◽  
Vol 415-417 ◽  
pp. 1391-1394
Author(s):  
Rui Bin Mei ◽  
Chang Sheng Li ◽  
Xiang Hua Liu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Rolling Process ◽  
Air Cooling ◽  
Water Cooling ◽  
Cooling Process ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Hot Strip

It is necessary to know the heat transfer intensity for predicting temperature distribution in the hot strip rolling process. The HTC (heat transfer coefficient) was usually obtained by the experiments and mathematical model. In this paper the HTC prediction was discussed based on the measured or target temperature by the proposed finite element method (FEM). The temperature evolution and HTC in the hot strip rolling process according to a certain plant were analyzed by the iteration calculation. The result shows that the HTC between strip and work roll was much more than the value in the air cooling and water cooling process. Furthermore, the HTC value is lower in the air cooling process compared with that of water cooling. The maximum and minimum value of HTC were about 1.5×105 (W/m2.K) and 80(W/m2.K) respectively. The temperature in the rough rolling according to the predicted HTC has been solved and the calculated results have a good agreement to the meausred value. Therefore, the research could be used to control the temperature distribution accurately and optimize the parameters.

Gas Circulation Due an Azimuthal Temperature Distribution Over a Micro-Tube Wall

2009 ◽  
Author(s):  
Felix Sharipov
Keyword(s):  
Numerical Calculation ◽  
Kinetic Equation ◽  
Temperature Distribution ◽  
Cross Section ◽  
Gas Flow ◽  
Tube Wall ◽  
Two Dimensional ◽  
Wide Range ◽  
Gas Circulation

In many applications, a temperature of fixed cross section of micro-tube is not uniform, but it can deviate from its equilibrium value. In this case the gas flow is not axi-symmetrical any more, but the flow is two dimensional. Under such conditions, the density cannot be considered as uniform across the section and gas circulations can occur. The aim of the present work is numerical calculation of distributions of velocity, density and temperature caused by an azimuthal temperature distribution over the tube wall. The problem is solved on the basis of the kinetic equation over a wide range of the gas rarefaction.

ALLEGHENY STAINLESS TYPE 405

Alloy Digest ◽  
1985 ◽  
Vol 34 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Critical Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Ductile Material ◽  
Air Cooling ◽  
Temperature Performance

Abstract ALLEGHENY STAINLESS Type 405, unlike most other 12% chromium steels, is not subject to appreciable hardening through air cooling from high temperatures. This is an advantageous characteristic in those applications where a soft, ductile material is required after rapid cooling from above the critical temperature. The nonhardening tendency of Type 405 also retards the formation of hardening cracks where welding is employed. Its uses include annealing boxes and baffles where hardening during cooling would be undesirable. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as heat treating and machining. Filing Code: SS-461. Producer or source: Allegheny Ludlum Corporation.

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