The Longitudinal Temperature Distribution in Active Fibers under Lasing Condition

2015 ◽  
Author(s):  
O.A. Ryabushkin ◽  
K.U. Prusakov ◽  
V.E. Sypin
Keyword(s):  
Temperature Distribution ◽  
Longitudinal Temperature ◽  
Lasing Condition

High-speed isotachophoresis. Analytical aspects of the steady-state longitudinal temperature profiles

1979 ◽  
Vol 44 (3) ◽  
pp. 841-853 ◽  
Author(s):  
Zbyněk Ryšlavý ◽  
Petr Boček ◽  
Miroslav Deml ◽  
Jaroslav Janák
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Minor Component ◽  
Physical Models ◽  
Temperature Profiles ◽  
Longitudinal Temperature ◽  
Continuous Character

The problem of the longitudinal temperature distribution was solved and the bearing of the temperature profiles on the qualitative characteristics of the zones and on the interpretation of the record of the separation obtained from a universal detector was considered. Two approximative physical models were applied to the solution: in the first model, the temperature dependences of the mobilities are taken into account, the continuous character of the electric field intensity at the boundary being neglected; in the other model, the continuous character of the electric field intensity is allowed for. From a comparison of the two models it follows that in practice, the variations of the mobilities with the temperature are the principal factor affecting the shape of the temperature profiles, the assumption of a discontinuous jump of the electric field intensity at the boundary being a good approximation to the reality. It was deduced theoretically and verified experimentally that the longitudinal profiles can appreciably affect the longitudinal variation of the effective mobilities in the zone, with an infavourable influence upon the qualitative interpretation of the record. Pronounced effects can appear during the analyses of the minor components, where in the corresponding short zone a temperature distribution occurs due to the influence of the temperatures of the neighbouring zones such that the temperature in the zone of interest in fact does not attain a constant value in axial direction. The minor component does not possess the steady-state mobility throughout the zone, which makes the identification of the zone rather difficult.

Dynamic Simulation on Longitudinal Temperature Distribution of Tunnel Ceiling Based on Moving Fire Source

2012 ◽  
Vol 610-613 ◽  
pp. 752-761
Author(s):  
Jun Deng ◽  
Shi Rong Li ◽  
Zheng Xin Yan
Keyword(s):  
Temperature Distribution ◽  
Dynamic Simulation ◽  
Natural Ventilation ◽  
Early Stage ◽  
Influential Factors ◽  
Simulation Software ◽  
Road Tunnel ◽  
Moving Vehicle ◽  
Fire Source ◽  
Longitudinal Temperature

Several tunnel fires were caused by the fire source loaded in moving vehicle. The physical model was designed based on real road tunnel to simulate the distribution of longitudinal temperature. Through fire dynamic simulation software FDS, the fire processes when moving vehicle stabilized and traveled at 10m/s and 15m/s in tunnel were simulated under natural ventilation of 2.7m/s. The purpose of research includes three aspects, first, the temperature field in the early stage when moving fire travels into tunnel; second, influence of moving fire on the longitudinal temperature distribution; third, explores the change of temperature peak and its influential factors when vehicles stops and combustion stabilizes. Simulation indicates that the airflow filed movement induced by moving fire to certain degree blocks the spread of heat released in the direction opposite to fire movement and it also entrains high temperature airflow into its movement. When ventilation direction is accordant with vehicle moving direction, the stabilized value of highest temperature point of ceiling tends to be higher than that when the directions are opposite.

Optimum Cylinder Cooling for Advanced Diesel Engines

1998 ◽  
Vol 120 (3) ◽  
pp. 657-663 ◽  
Author(s):  
F. Trenc ◽  
S. Rodman ◽  
L. Skerget ◽  
M. Delic
Keyword(s):  
Temperature Distribution ◽  
Thermal Stresses ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Experimental Investigations ◽  
Cylinder Wall ◽  
Curved Channels ◽  
Longitudinal Temperature ◽  
Oil Flow ◽  
Flow Phenomena

Continuous demand for higher specific engine output simultaneously introduces problems of higher mechanical and thermal stresses of the engine components. Uneven temperature distribution in the cylinder wall of a diesel engine, especially when air-cooled, is well known. Peak local temperatures, large circumferential and longitudinal temperature gradients provoke deformations that, in turn, affect the reliability of the engine. As the result of intensive numerical and experimental investigations, a horizontal, curved channel fed with engine lubrication oil was introduced in the upper part of the air-cooled cylinder. Optimization of the channel design, its position, and determination of suitable asymmetrical split oil flow have led to more favorable cylinder temperature distribution, similar to that obtained by advanced water-cooled engines. Analyses of the local laminar oil-flow phenomena and local heat transfer distribution in curved channels are discussed in the paper and can be successfully applied to advanced liquid-cooled engines.

scholarly journals Establishing the Longitudinal Temperature Distribution for Fully Developed Turbulent Flow in a Gas Turbine Exhaust Duct

1970 ◽  
Author(s):  
P. J. Torpey ◽  
R. M. Welch
Keyword(s):  
Temperature Distribution ◽  
Gas Turbine ◽  
Accurate Determination ◽  
Exhaust System ◽  
Longitudinal Temperature ◽  
Exhaust Duct ◽  
Fully Developed Turbulent Flow ◽  
Gas Turbine Exhaust ◽  
Heat Flow Model ◽  
Turbine Exhaust

The ability to predict the longitudinal temperature distribution along a gas turbine exhaust duct facilitates the selection of the proper duct material and the appropriate paint or other external coating. It also allows accurate determination of thermal expansion over the entire length. A first-order differential equation is derived from a one-dimensional heat flow model for the exhaust system. A digital computer program employing this model is also presented. The computer solution, in addition to eliminating tedious manual computation, extends the analysis capability by accounting for changes in temperature and flow-dependent variables along the duct length. Measured gas and duct wall temperatures for a 1.5-kw gas turbine exhaust system are compared with values predicted by the analysis. Good agreement is noted throughout that portion of the system in which fully developed flow exists.

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