In order to improve the detection accuracy of Doppler asymmetric spatial heterodyne(DASH)interferometer in harsh temperatures,an opto-mechanical-thermal integration analysis is carried out.Firstly,the correlation betw...In order to improve the detection accuracy of Doppler asymmetric spatial heterodyne(DASH)interferometer in harsh temperatures,an opto-mechanical-thermal integration analysis is carried out.Firstly,the correlation between the interference phase and temperature is established according to the working principle and the phase algorithm of the interferometer.Secondly,the optical mechanical thermal analysis model and thermal deformation data acquisition model are designed.The deformation data of the interference module and the imaging optical system at different temperatures are given by temperature load simulation analysis,and the phase error caused by thermal deformation is obtained by fitting.Finally,based on the wind speed error caused by thermal deformation of each component,a reasonable temperature control scheme is proposed.The results show that the interference module occupies the main cause,the temperature must be controlled within(20±0.05)℃,and the temperature control should be carried out for the temperature sensitive parts,and the wind speed error caused by the part is 3.8 m/s.The thermal drift between the magnification of the imaging optical system and the thermal drift of the relative position between the imaging optical system and the detector should occupy the secondary cause,which should be controlled within(20±2)℃,and the wind speed error caused by the part is 3.05 m/s.In summary,the wind measurement error caused by interference module,imaging optical system,and the relative position between the imaging optical system and the detector can be controlled within 6.85 m/s.The analysis and temperature control schemes presented in this paper can provide theoretical basis for DASH interferometer engineering applications.展开更多
Metal organic chemical vapor deposition(MOCVD) is a key equipment in the manufacturing of semiconductor optoelectronic devices and microwave devices in industry. Heating system is a vital part of MOCVD. Specific heati...Metal organic chemical vapor deposition(MOCVD) is a key equipment in the manufacturing of semiconductor optoelectronic devices and microwave devices in industry. Heating system is a vital part of MOCVD. Specific heating device and thermal control technology are needed for each new reactor design. By using resistance-wire heating MOCVD reaction chamber model, thermal analysis and structure optimization of the reactor were developed from the vertical position and the distance between coils of the resistance-wire heater. It is indicated that, within a certain range, the average temperature of the graphite susceptor varies linearly with the vertical distance of heater to susceptor, and with the changed distances between the coils; furthermore, single resistance-wire heater should be placed loosely in the internal and tightly in the external. The modulate accuracy of the temperature field approximately equals the change of the average temperature corresponding to the change of the coil position.展开更多
Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment impro...Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment improvement in winter was investigated by carrying out field experiments in Heqingyuan residential area in Beijing,and after that,numerical simulation with SPOTE(simulation platform for outdoor thermal environment) experiments for outdoor thermal environment of vegetation was adopted for comparison.The conclusions were summarized as follows:1) By comparing the experimental data with simulation results,it could be concluded that the wind field simulated was consistent with the actual wind field,and the flow distribution impacted by vegetation could be accurately reflected;2) The wind velocity with vegetation was lower than that without vegetation,and the wind velocity was reduced by 46%;3) By adjusting arrangement and types of vegetation in the regions with excessively large wind velocity,the pedestrian-level wind velocity could be obviously improved through the simulation and comparison.展开更多
The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was propo...The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was proposed using a commercial analysis program, ANSYS Workbench 12, by analyzing the static-thermal characteristics of the developed high-accuracy tilting index table at its design stage. The results of the performed structural analysis show that the maximum stress is generated at the stock tail part. An optimum design for the stock tail part was carried out to reduce the maximum stress and deformation. Also, the design variables were determined by considering the support of the stock tail part for the C-axis body. In the comparison of the results before and after the optimization, the maximum deformation and stress are improved by 2.8% and 8%, respectively.展开更多
In order to solve the heat damages in deep mines, a cool-wall cooling technology and its working model are proposed based on the principles of heat absorption and insulation in this paper. During this process, the dif...In order to solve the heat damages in deep mines, a cool-wall cooling technology and its working model are proposed based on the principles of heat absorption and insulation in this paper. During this process, the differential equation of thermal equilibrium for roadway control unit is built, and the heat adsorption control equation of cool-wall cooling system is derived by an integral method, so as to obtain the quantitative relationship among the heat absorption capacity of cooling system, the heat dissipating capacity of surrounding rock and air temperature change. Then, the heat absorption capacity required by air temperature less than the standard value for safety is figured out by section iterative method with the simultaneous solution of heat absorption control equation and the heat dissipation density equation of surrounding rock. Finally, the results show that as the air temperature at the inlet of roadway is 25 ℃, the roadway wall is covered by heat-absorbing plate up to 39% of the area, as well as the cold water is injected into the heat-absorbing plate with a temperature of 20 ℃ and a mass flow of 113.6 kg/s, the air flow temperature rise per kilometer in the roadway can be less than 3 ℃.展开更多
文摘In order to improve the detection accuracy of Doppler asymmetric spatial heterodyne(DASH)interferometer in harsh temperatures,an opto-mechanical-thermal integration analysis is carried out.Firstly,the correlation between the interference phase and temperature is established according to the working principle and the phase algorithm of the interferometer.Secondly,the optical mechanical thermal analysis model and thermal deformation data acquisition model are designed.The deformation data of the interference module and the imaging optical system at different temperatures are given by temperature load simulation analysis,and the phase error caused by thermal deformation is obtained by fitting.Finally,based on the wind speed error caused by thermal deformation of each component,a reasonable temperature control scheme is proposed.The results show that the interference module occupies the main cause,the temperature must be controlled within(20±0.05)℃,and the temperature control should be carried out for the temperature sensitive parts,and the wind speed error caused by the part is 3.8 m/s.The thermal drift between the magnification of the imaging optical system and the thermal drift of the relative position between the imaging optical system and the detector should occupy the secondary cause,which should be controlled within(20±2)℃,and the wind speed error caused by the part is 3.05 m/s.In summary,the wind measurement error caused by interference module,imaging optical system,and the relative position between the imaging optical system and the detector can be controlled within 6.85 m/s.The analysis and temperature control schemes presented in this paper can provide theoretical basis for DASH interferometer engineering applications.
基金Projects(61376076,61274026,61377024)supported by the National Natural Science Foundation of ChinaProjects(12C0108,13C321)supported by the Scientific Research Fund of Hunan Provincial Education Department,ChinaProjects(2013FJ2011,2013FJ4232)supported by the Science and Technology Plan of Hunan Province,China
文摘Metal organic chemical vapor deposition(MOCVD) is a key equipment in the manufacturing of semiconductor optoelectronic devices and microwave devices in industry. Heating system is a vital part of MOCVD. Specific heating device and thermal control technology are needed for each new reactor design. By using resistance-wire heating MOCVD reaction chamber model, thermal analysis and structure optimization of the reactor were developed from the vertical position and the distance between coils of the resistance-wire heater. It is indicated that, within a certain range, the average temperature of the graphite susceptor varies linearly with the vertical distance of heater to susceptor, and with the changed distances between the coils; furthermore, single resistance-wire heater should be placed loosely in the internal and tightly in the external. The modulate accuracy of the temperature field approximately equals the change of the average temperature corresponding to the change of the coil position.
基金Project(50878111) supported by the National Natural Science Foundation of China
文摘Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment improvement in winter was investigated by carrying out field experiments in Heqingyuan residential area in Beijing,and after that,numerical simulation with SPOTE(simulation platform for outdoor thermal environment) experiments for outdoor thermal environment of vegetation was adopted for comparison.The conclusions were summarized as follows:1) By comparing the experimental data with simulation results,it could be concluded that the wind field simulated was consistent with the actual wind field,and the flow distribution impacted by vegetation could be accurately reflected;2) The wind velocity with vegetation was lower than that without vegetation,and the wind velocity was reduced by 46%;3) By adjusting arrangement and types of vegetation in the regions with excessively large wind velocity,the pedestrian-level wind velocity could be obviously improved through the simulation and comparison.
基金Project(70004782) supported by the Regional Strategic Technology Development Program of the Ministry of Knowledge Economy(MKE) of KoreaProject(2011-0017407) supported by the National Research Foundation of Korea (NRF) Funded by the Korea Government (MEST)
文摘The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was proposed using a commercial analysis program, ANSYS Workbench 12, by analyzing the static-thermal characteristics of the developed high-accuracy tilting index table at its design stage. The results of the performed structural analysis show that the maximum stress is generated at the stock tail part. An optimum design for the stock tail part was carried out to reduce the maximum stress and deformation. Also, the design variables were determined by considering the support of the stock tail part for the C-axis body. In the comparison of the results before and after the optimization, the maximum deformation and stress are improved by 2.8% and 8%, respectively.
基金Project(2018CXNL08) supported by the Fundamental Research Funds for the Central Universities,China。
文摘In order to solve the heat damages in deep mines, a cool-wall cooling technology and its working model are proposed based on the principles of heat absorption and insulation in this paper. During this process, the differential equation of thermal equilibrium for roadway control unit is built, and the heat adsorption control equation of cool-wall cooling system is derived by an integral method, so as to obtain the quantitative relationship among the heat absorption capacity of cooling system, the heat dissipating capacity of surrounding rock and air temperature change. Then, the heat absorption capacity required by air temperature less than the standard value for safety is figured out by section iterative method with the simultaneous solution of heat absorption control equation and the heat dissipation density equation of surrounding rock. Finally, the results show that as the air temperature at the inlet of roadway is 25 ℃, the roadway wall is covered by heat-absorbing plate up to 39% of the area, as well as the cold water is injected into the heat-absorbing plate with a temperature of 20 ℃ and a mass flow of 113.6 kg/s, the air flow temperature rise per kilometer in the roadway can be less than 3 ℃.
