An Analytical Solution Countercurrent Heat Transfer Between Parallel Vessels With a Linear Axial Temperature Gradient

1988 ◽  
Vol 110 (3) ◽  
pp. 254-256 ◽  
Author(s):  
E. H. Wissler
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Heat Exchange ◽  
Temperature Gradient ◽  
Infinite Medium ◽  
Linear Temperature ◽  
Linear Temperature Gradient ◽  
Axial Temperature ◽  
Mixed Mean ◽  
The Difference

Presented in this paper is a solution for countercurrent heat exchange between two parallel vessels embedded in an infinite medium with a linear temperature gradient along the axes of the vessels. The velocity profile within the vessel is assumed to be parabolic. This solution describes the temperature field within the vessels, as well as in the tissue, and establishes that the intravessel temperature is not uniform, as is generally assumed to be the case. An explicit expression for the intervessel thermal resistance based on the difference between cup-mixed mean temperatures is derived.

scholarly journals Microfluidic Platform for Analyzing the Thermotaxis of C. elegans in a Linear Temperature Gradient

2017 ◽  
Vol 33 (12) ◽  
pp. 1435-1440 ◽  
Author(s):  
Sunhee YOON ◽  
Hailing PIAO ◽  
Tae-Joon JEON ◽  
Sun Min KIM
Keyword(s):  
Temperature Gradient ◽  
Linear Temperature ◽  
Microfluidic Platform ◽  
C Elegans ◽  
Linear Temperature Gradient

scholarly journals Analysis of Heat Transfer Mechanism for Shelf Vacuum Freeze-Drying Equipment

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hong-Ping Cheng ◽  
Shian-Min Tsai ◽  
Chin-Chi Cheng
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Low Temperature ◽  
Temperature Gradient ◽  
Freeze Drying ◽  
Heat Transfer Fluid ◽  
Processing Temperature ◽  
Fluid Temperature ◽  
Three Dimension ◽  
Flow Rates

Vacuum freeze-drying technology is applicable to the process of high heat-sensitive products. Due to the long drying period and extremely low processing temperature and pressure, the uniform and efficiency of heat transfer fluid temperature in shelf are critical for product quality. Therefore, in this study, the commercial computer fluid dynamics (CFD) software, FLUENT, was utilized for three-dimension numerical simulation of the shelf vacuum freeze-drying process. The influences of different inlet and outlet positions for shelves on the uniformity of the flow rate and temperature were discussed. Moreover, it explored the impacts on the temperature gradient of shelves after heat exchange of different flow rates and low temperature materials. In order to reduce the developing time and optimize the design, the various secondary refrigerants in different plies of shelves were investigated. According to the effect of heat exchange between different flow rates and low temperature layer material shelves on the temperature gradient of shelves surface, the minimum temperature gradient was 20 L/min, and the maximum was 2.5 L/min.

scholarly journals Heat Exchange Evaluation at Thermo-Adhezion Method of Extraction of Diamond Raw from Kimberlite Ore

2018 ◽  
Vol 8 (1) ◽  
pp. 23
Author(s):  
P. P. Sharin ◽  
M. P. Lebedev ◽  
G. M. Nikitin ◽  
G. G. Vinokurov ◽  
M. P. Akimova
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Exchange ◽  
High Selectivity ◽  
Waste Rock ◽  
The Difference ◽  
Method Of Extraction

In the work thermo-adhesion a method of selecting and extracting the grains of diamond from a mixture of related minerals is developed. The study presents estimates of the heat transfer of the proposed scheme extraction based on the difference between the thermal conductivity of diamond and related minerals. The high selectivity thermo-adhesion selection and extraction of diamonds with the division concentrate on useful component and waste rock is shown.

scholarly journals The Namib Turbulence Experiment: Investigating surface-atmosphere heat transfer in three dimensions

2021 ◽  
Keyword(s):  
Heat Transfer ◽  
Surface Layer ◽  
Temperature Field ◽  
Heat Exchange ◽  
High Resolution ◽  
Three Dimensional ◽  
Temperature Fluctuations ◽  
Near Surface ◽  
Turbulent Heat Exchange ◽  
Wide Range

Abstract The Namib Turbulence EXperiment (NamTEX) was a multi-national micrometeorological campaign conducted in the Central Namib Desert to investigate three-dimensional surface layer turbulence and the spatio-temporal patterns of heat transfer between the sub-surface, surface, and atmosphere. The Namib provides an ideal location for fundamental research that revisits some key assumptions in micrometeorology that are implicitly included in the parameterizations describing energy exchange in weather forecasting and climate models: Homogenous flat surfaces, no vegetation, little moisture, and cloud-free skies create a strong and consistent diurnal forcing, resulting in a wide range of atmospheric stabilities. A novel combination of instruments was used to simultaneously measure variables and processes relevant to heat transfer: A three km fibre-optic distributed temperature sensor (DTS) was suspended in a pseudo-three-dimensional array within a 300 m x 300 m domain to provide vertical cross-sections of air temperature fluctuations. Aerial and ground-based thermal imagers recorded high resolution surface temperature fluctuations within the domain and revealed the spatial thermal imprint of atmospheric structures responsible for heat exchange. High-resolution soil temperature and moisture profiles together with heat flux plates provided information on near-surface soil dynamics. Turbulent heat exchange was measured with a vertical array of five eddy-covariance point measurements on a 21-m mast, as well as by co-located small- and large-aperture scintillometers. This contribution first details the scientific goals and experimental set-up of the NamTEX campaign. Then using a typical day, we demonstrate i) the coupling of surface layer, surface, and soil temperatures using high-frequency temperature measurements, ii) differences in spatial and temporal standard deviations of the horizontal temperature field using spatially distributed measurements, and iii) horizontal anisotropy of the turbulent temperature field.

scholarly journals Internal Force Analysis of Parabolic Arch Considering Shear Effect under Gradient Temperature

2021 ◽  
Vol 631 (1) ◽  
pp. 012053
Author(s):  
Fulin Shen ◽  
Xiaochun Song
Keyword(s):  
Temperature Gradient ◽  
Axial Force ◽  
Slenderness Ratio ◽  
Bending Moment ◽  
Internal Force ◽  
Gradient Field ◽  
Parameter Study ◽  
Linear Temperature ◽  
Linear Temperature Gradient ◽  
Parabolic Arch

Abstract This paper theoretical analysis the internal force of the fixed parabolic arches under radient temperature gradient field incorporating shear deformations. The effective centroid of the arch-section under linear temperature gradient is derived. Based on force method and energy method, the analytical solutions of the internal force of fixed parabolic arches at pre-buckling under linear temperature gradient field are derived. A parameter study was carried out to study the influence of linear temperature gradient on the internal force of the fixed parabolic arches with different rise-span ratio and varying slenderness ratio. It is found that the temperature gradient and the rise-span ratio has a significant influence on the internal force of the parabolic arches, the influence of shear deformation causes the bending moment increase while the axial force decreases, and the axial force of parabolic arches decreases as the rise-span ratio increases.

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