Calculation method of shrouded radar target surface temperature field

2017 ◽  
Vol 46 (4) ◽  
pp. 404002
Author(s):  
陈 珊 Chen Shan ◽  
马俊春 Ma Junchun ◽  
刘朝辉 Liu Chaohui ◽  
王 忠 Wang Zhong
Keyword(s):  
Temperature Field ◽  
Surface Temperature ◽  
Calculation Method ◽  
Target Surface ◽  
Radar Target ◽  
Surface Temperature Field

A calculation method of thermal deformation for double helical gear

2019 ◽  
Vol 20 (6) ◽  
pp. 612
Author(s):  
Cheng Wang
Keyword(s):  
Temperature Field ◽  
Surface Temperature ◽  
Calculation Method ◽  
Thermal Deformation ◽  
Linear Interpolation ◽  
Helical Gear ◽  
Tooth Surface ◽  
Partial Load ◽  
Gear Modification ◽  
Surface Temperature Field

Thermal deformation caused by gear transmission is an important factor causing gear impact, vibration and partial load. Gear modification can effectively improve the effects caused by thermal deformation. The calculation of thermal deformation is the first problem to be solved before gear modification. This paper takes double helical gear as the research object and a calculation method of thermal deformation is proposed. Firstly, temperature of instantaneous meshing points on the tooth surface are measured and these discrete temperature values are fitted by the linear interpolation. Calculation formula of temperature distribution along gear radial direction is introduced. Combining both, tooth surface temperature field is obtained. Secondly, equation of tooth surface for double helical gear before and after thermal deformation is derived according to the tooth surface temperature field. Finally, an example is given. Compared with the given modification of thermal deformation, the calculated thermal deformation is almost equal to theoretical value. On this basis, the thermal deformation of double helical gear considering the installation error and machining error is calculated, which provides a theoretical basis for thermal deformation modification of double helical gear.

scholarly journals Study on the Influence of Surface Temperature Field of Aluminum Alloy Etched by Laser Water Jet Composite Machining

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3206
Author(s):  
Xuehui Chen ◽  
Xin Xu ◽  
Wei Liu ◽  
Lei Huang ◽  
Hao Li ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Temperature Field ◽  
Surface Temperature ◽  
Process Parameters ◽  
Water Jet ◽  
Laser Machining ◽  
Material Surface ◽  
Laser Etching ◽  
Surface Temperature Field

This paper studies the compound effect of liquid medium and laser on the workpiece and analyses the law of material surface temperature change during the processing. Taking 7075-T6 aluminum alloy as the research object, the surface temperature field of aluminum alloy processed using water-jet-assisted laser machining under different process parameters was simulated using finite element software. In addition, the temperature field of the material surface was detected in real-time using the self-built water-jet-assisted laser machining temperature field detection system, and the processing results were observed and verified using an optical microscope, scanning electron microscope, and energy spectrum analyzer. The results show that when the water jet inflow angle is 45°, the heat-affected area of the material surface is the smallest, and the cooling effect of the temperature field of the material surface is better. Considering the liquidus melting point of 7075 aluminum alloys, it is concluded that the processing effect is better when the water jet velocity is 14 m·s−1, the laser power is 100 W, and the laser scanning speed is 1.2 mm·s−1. At this time, the quality of the tank is relatively good, there are no cracks in the bottom of the tank, and there is less slag accumulation. Compared with anhydrous laser etching, water-jet-assisted laser etching can reduce the problems of micro-cracks, molten slag, and the formation of a recast layer in laser etching and improve the quality of the workpiece, and the composition of the bottom slag does not change. This study provides theoretical guidance and application support for the selection and optimization of process parameters for water-jet-assisted laser etching of aluminum alloy and further enriches the heat transfer mechanism of multi-field coupling in the process of water-jet-assisted laser machining.

SURFACE TEMPERATURE FIELD MODEL AND INFLUENCE FACTORS OF HF CVD DIAMOND FILMS ON WC–Co ALLOYS

2006 ◽  
Vol 13 (05) ◽  
pp. 661-668
Author(s):  
SHA LIU ◽  
JING QIU ZHANG
Keyword(s):  
Temperature Field ◽  
Surface Temperature ◽  
Field Model ◽  
Influence Factors ◽  
Diamond Films ◽  
Thermal Source ◽  
Heat Conductivity Coefficient ◽  
Temperature Field Model ◽  
Surface Temperature Field ◽  
Co Alloys

The surface temperature field model of hot filament chemical vapor deposition (HF CVD) diamond films on WC – Co alloys was constructed and calculated by taking into account the influences of both thermal source properties and physical properties of substrates. Under the certain conditions of some parameters, the effects of the influence factors such as the maximum specific heat flux (q m ), the heat conductivity coefficient (λ) of the substrate and the substrate height (h) on the surface temperature field were exhibited quickly and clearly by the computer modeling. The theoretical calculating data are close to the experimental results. It is found that the influences of the thermal source parameter, the substrate height, and the heat conductivity coefficient of the substrate materials on the surface temperature field of diamond films on WC – Co alloys are almost equally important.

The thermal signature of a vortex pair impacting a free surface

2001 ◽  
Vol 444 ◽  
pp. 49-78 ◽  
Author(s):  
GEOFFREY B. SMITH ◽  
R. J. VOLINO ◽  
R. A. HANDLER ◽  
R. I. LEIGHTON
Keyword(s):  
Boundary Layer ◽  
Temperature Field ◽  
Surface Temperature ◽  
Numerical Experiments ◽  
Thermal Boundary Layer ◽  
Vortex Pair ◽  
Water Interface ◽  
Physical Experiments ◽  
Air Water Interface ◽  
Surface Temperature Field

The action of a rising vortex pair on the thermal boundary layer at an air–water interface is studied both experimentally and numerically. The objective is to relate variations in the surface temperature field to the hydrodynamics of the vortex pair below. The existence of a thermal boundary layer on the water side of an air–water interface is well known; it is this boundary layer which is disrupted by the action of the vortex system. Experimentally, the vortices were generated via the motion of a pair of submerged flaps. The flow was quantified through simultaneous measurement of both the subsurface velocity field, via digital particle image velocimetry (DPIV), and the surface temperature field, via an infrared (IR) sensitive imager. The results of the physical experiments show a clearly defined disruption of the ambient thermal boundary layer which is well correlated with the vorticity field below. Numerical experiments were carried out in a parameter space similar to that of the physical experiments. Included in the numerical experiments was a simple surfactant model which enabled the exploration of the complex role surface elasticity played in the vortex–free surface interaction. The results of this combined experimental and numerical investigation suggest that surface straining rate is an important parameter in correlating the subsurface flow with the surface temperature field. A model based on surface straining rate is presented to explain the interaction.

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