Maximum temperature drops and thermoelastic stresses in the symmetric heating of prisms and parallelepipeds

1971 ◽  
Vol 3 (12) ◽  
pp. 1405-1406
Author(s):  
N. Yu. Taits ◽  
A. G. Sabel'nikov ◽  
A. N. Minaev ◽  
V. V. Moshura
1971 ◽  
Vol 7 (5) ◽  
pp. 512-515 ◽  
Author(s):  
V. M. Guba ◽  
Yu. B. Postol'nik ◽  
V. A. Garanchuk

1982 ◽  
Vol 104 (3) ◽  
pp. 501-507 ◽  
Author(s):  
R. A. Wirtz ◽  
R. J. Stutzman

Laboratory experiments on natural convection of air between vertical parallel plates with uniform and symmetric heat fluxes are reported. Data collection was through direct temperature measurement using thermocouples and through analysis of interferograms of the flow. Data were collected over a range of heat fluxes and geometric parameters where the flow was in the developing temperature field regime. A correlation is developed that allows for the calculation of the maximum temperature variation of the plates for a given input heat flux and plate geometry. The equation is expected to be accurate to ±5 percent.


2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.


Agrotek ◽  
2018 ◽  
Vol 2 (6) ◽  
Author(s):  
Wilson Palelingan Aman

<em>A research about cocoa beans drying used solar tunnel dryer with photovoltaic module driven have conducted in Manokwari. Solar tunnel dryer used in this research adapted from type Hohenheim with photovoltaic module and integrated air heat collector has been installed at the Department of Agricultural Technology, Papua State University Manokwari to dried cocoa beans. The objectives of this research were to design solar tunnel dryer and evaluate it�s performance in dryed cocoa beans. The result obtained was a new construction of solar tunnel dryer for cocoa beans with dimensions 6 m of length and 0,9 m of wide. The dryer completed with photovoltaic module to drive the blowers of hot drying air. �Performance test of the dryer showed that drying of 10 kg of cocoa beans with initial moisture content about 70% wet basis needed 13 hours of drying time to achieved final moisture content about 7,17% wet basis. The drying time achieved was faster compared than traditional solar drying that needed 20 hours of drying time. The maximum temperature achieved in drying chamber was 60 <sup>o</sup>C.</em>


Author(s):  
Rama R. Goruganthu ◽  
David Bethke ◽  
Shawn McBride ◽  
Tom Crawford ◽  
Jonathan Frank ◽  
...  

Abstract Spray cooling is implemented on an engineering tool for Time Resolved Emission measurements using a silicon solid immersion lens to achieve high spatial resolution and for probing high heat flux devices. Thermal performance is characterized using a thermal test vehicle consisting of a 4x3 array of cells each with a heater element and a thermal diode to monitor the temperature within the cell. The flip-chip packaged TTV is operated to achieve uniform heat flux across the die. The temperature distribution across the die is measured on the 4x3 grid of the die for various heat loads up to 180 W with corresponding heat flux of 204 W/cm2. Using water as coolant the maximum temperature differential across the die was about 30 °C while keeping the maximum junction temperature below 95 °C and at a heat flux of 200 W/cm2. Details of the thermal performance of spray cooling system as a function of flow rate, coolant


2019 ◽  
Vol 56 (4) ◽  
pp. 750-758
Author(s):  
Nicolae Navodariu ◽  
Mihai Branzei ◽  
Robert Ciocoiu ◽  
Ion Ciuca ◽  
Razvan Coman ◽  
...  

Flame straightening is a technology process used to eliminate deformations. This method relies on local heating of the material to correct geometry or damaged parts. In the local automobile services its main use is for repairs of less critical deformed components. The maximum temperature and thermal gradient, heating time, cooling rate and number of heating cycles affect the mechanical properties since local heating can alter material microstructure. The aim of this research was to determine the mechanical characteristics of thin steel plates repaired by local heating associated with plastic deformation (similar to hot working) and cold straightening (similar to local cold working) for automotive side and door panels made of structural steel. Thin sheet plates, 0.9mm thickness, were deformed by impact and repaired by local heating using the flame and induction heating then plastically deformed while hot as well as straightened without heating. The heat repaired samples were studied by light microscopy to determine microstructure change and samples were tensile tested to determine their mechanical characteristics. Local excessive grain growth generates anisotropy, the assembly behaves as a composite material with regions that show significant plastic deformations while others little or no deformations at al. Without procedures adjusted to each material repairs involving heating are to be avoided, cold working should be employed when replacement is not possible.


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