A new method is presented for getting the general thermal response factors and z-transfer functioncoefficients of a room by synthesizing them from the thermal response factors of different parts of the thermalinsulati...A new method is presented for getting the general thermal response factors and z-transfer functioncoefficients of a room by synthesizing them from the thermal response factors of different parts of the thermalinsulation structure. How to use the general thermal response factors and z-transfer function coefficients toca1culate the indoor air temperature variation directly is also studied. It is shown through practical use that it iseasy to program with the methods presented in this paper and the calculated results are reliable.展开更多
This work presents a semi-analytical model to explore the effects of cooling rate on the thermal shock resistance behavior of a functionally graded ceramic （FGC） plate with a periodic array of edge cracks. The FGC i...This work presents a semi-analytical model to explore the effects of cooling rate on the thermal shock resistance behavior of a functionally graded ceramic （FGC） plate with a periodic array of edge cracks. The FGC is assumed to be a thermally heterogeneous material with constant elastic modulus and Poisson＇s ratio. The cooling rate applied at the FGC surface is modeled using a linear ramp function. An integral equation method and a closed form asymptotic temperature solution are employed to compute the thermal stress intensity factor （TSIF）. The thermal shock residual strength and critical thermal shock of the FGC plate are obtained using the SIF criterion. Thermal shock simulations for an Al2O/Si3N4 FGC indicate that a finite cooling rate leads to a significantly higher critical thermal shock than that under the sudden cooling condition. The residual strength, however, is relatively insensitive to the cooling rate.展开更多
This paper analyzes the convective heat transfer enhancement mechanism of latent heat functionally thermal fluid. By using the proposed internal heat source model, the influence of each factor affecting the heat trans...This paper analyzes the convective heat transfer enhancement mechanism of latent heat functionally thermal fluid. By using the proposed internal heat source model, the influence of each factor affecting the heat transfer enhancement of laminar flow in a circular tube with constant heat flux is analyzed. The main influencing factors and the mechanisms of heat transfer enhancement are clarified, and the influences of the main factors on the heat transfer enhancement are quantitatively analyzed. A modified Nusselt number for internal flow is introduced to describe more effectively the degree of heat transfer enhancement for latent functionally thermal fluid.展开更多
针对可持续发展科学卫星1号(SDGSAT-1)装载的微光多谱段相机安装面存在热变形,进而影响微光多谱段相机成像质量的问题,对微光多谱段相机的安装方式进行结构和隔热的优化设计,并对卫星在低温、高温工况下的温度场分布和热变形进行仿真分...针对可持续发展科学卫星1号(SDGSAT-1)装载的微光多谱段相机安装面存在热变形,进而影响微光多谱段相机成像质量的问题,对微光多谱段相机的安装方式进行结构和隔热的优化设计,并对卫星在低温、高温工况下的温度场分布和热变形进行仿真分析。结果表明:微光多谱段相机安装面在低温工况下的最大畸变为0.044 mm,在高温工况下的最大畸变为0.034 mm。控制安装界面的热变形量,并经地面试验和在轨验证,得到微光多谱段相机的在轨动态调制传递函数(modulation transfer function,MTF)≥0.1,满足要求。展开更多
Thermal batteries（TBs） as primary power sources are widely applied in defense and military affairs, and used in electronic packages and nuclear weapons. The activation time（AT） of TBs restricts the reactive speed ...Thermal batteries（TBs） as primary power sources are widely applied in defense and military affairs, and used in electronic packages and nuclear weapons. The activation time（AT） of TBs restricts the reactive speed of them. Therefore, it is a remarkably important parameter and needs to be studied in detail. In our previous study, the thermal transfer model has already been found during the activation process in TBs. In this work, the experimental TBs were fabricated and tested for validating the model. The error between the average value of test and calculation value from this model is less than 1%. As a result, the thermal transfer function for the activation process in the given TBs[FeSJLiC1-KCI（MgO）/LiSi containing Fe/KC104 heat pellet] is suggested.展开更多
文摘A new method is presented for getting the general thermal response factors and z-transfer functioncoefficients of a room by synthesizing them from the thermal response factors of different parts of the thermalinsulation structure. How to use the general thermal response factors and z-transfer function coefficients toca1culate the indoor air temperature variation directly is also studied. It is shown through practical use that it iseasy to program with the methods presented in this paper and the calculated results are reliable.
文摘This work presents a semi-analytical model to explore the effects of cooling rate on the thermal shock resistance behavior of a functionally graded ceramic （FGC） plate with a periodic array of edge cracks. The FGC is assumed to be a thermally heterogeneous material with constant elastic modulus and Poisson＇s ratio. The cooling rate applied at the FGC surface is modeled using a linear ramp function. An integral equation method and a closed form asymptotic temperature solution are employed to compute the thermal stress intensity factor （TSIF）. The thermal shock residual strength and critical thermal shock of the FGC plate are obtained using the SIF criterion. Thermal shock simulations for an Al2O/Si3N4 FGC indicate that a finite cooling rate leads to a significantly higher critical thermal shock than that under the sudden cooling condition. The residual strength, however, is relatively insensitive to the cooling rate.
基金supported by the National Natural Science Foundation of China(Grant No.50076020)the Key Projects of Basic Research and Development of China(Grant No.G2000026309)the Excellent Young Faculty Foundation of the Ministry of Education of China.
文摘This paper analyzes the convective heat transfer enhancement mechanism of latent heat functionally thermal fluid. By using the proposed internal heat source model, the influence of each factor affecting the heat transfer enhancement of laminar flow in a circular tube with constant heat flux is analyzed. The main influencing factors and the mechanisms of heat transfer enhancement are clarified, and the influences of the main factors on the heat transfer enhancement are quantitatively analyzed. A modified Nusselt number for internal flow is introduced to describe more effectively the degree of heat transfer enhancement for latent functionally thermal fluid.
文摘针对可持续发展科学卫星1号(SDGSAT-1)装载的微光多谱段相机安装面存在热变形,进而影响微光多谱段相机成像质量的问题,对微光多谱段相机的安装方式进行结构和隔热的优化设计,并对卫星在低温、高温工况下的温度场分布和热变形进行仿真分析。结果表明:微光多谱段相机安装面在低温工况下的最大畸变为0.044 mm,在高温工况下的最大畸变为0.034 mm。控制安装界面的热变形量,并经地面试验和在轨验证,得到微光多谱段相机的在轨动态调制传递函数(modulation transfer function,MTF)≥0.1,满足要求。
基金Supported by the National Natural Science Foundation of China（No.21573093）.
文摘Thermal batteries（TBs） as primary power sources are widely applied in defense and military affairs, and used in electronic packages and nuclear weapons. The activation time（AT） of TBs restricts the reactive speed of them. Therefore, it is a remarkably important parameter and needs to be studied in detail. In our previous study, the thermal transfer model has already been found during the activation process in TBs. In this work, the experimental TBs were fabricated and tested for validating the model. The error between the average value of test and calculation value from this model is less than 1%. As a result, the thermal transfer function for the activation process in the given TBs[FeSJLiC1-KCI（MgO）/LiSi containing Fe/KC104 heat pellet] is suggested.
