INVESTIGATION IN HEAT TRANSFER , VELOCITY AND TEMPERATURE PROFILES WITH CARBON DIOXIDE FLOW IN A TUBE OVER THE NEARLY CRITICAL REGION OF PARAMETERS

1974 ◽  
Author(s):  
Z. L. Miropolsky ◽  
V. I. Baigulov
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Critical Region ◽  
Temperature Profiles ◽  
Transfer Velocity

Paper 8: Heat Transfer from a Wire in the Critical Region

1967 ◽  
Vol 182 (9) ◽  
pp. 52-57 ◽  
Author(s):  
U. Grigull ◽  
E. Abadzic
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Natural Convection ◽  
Critical Point ◽  
Critical Region ◽  
High Speed ◽  
Nucleate Boiling ◽  
Flow Patterns ◽  
Film Boiling ◽  
High Speed Camera

This work deals with experimental results on boiling from a horizontal platinum wire, 0·1 mm in diameter, submerged in saturated liquids as carbon dioxide (CO2) and Freon 13 (CF3Cl) in the critical region. Three discrete regimes without steady transition could be observed: natural convection, nucleate boiling, and film boiling. Near the critical point particular flow patterns appeared in the rising vapour in film boiling: regular bubbles, vapour columns, and vapour hazes with garland-like boundaries. These flow patterns could be simulated in model experiments with liquids and were also photographed with a high-speed camera.

Heat Transfer by Free Convection From a Horizontal Wire to Carbon Dioxide in the Critical Region

1968 ◽  
Vol 90 (1) ◽  
pp. 51-55 ◽  
Author(s):  
R. J. Goldstein ◽  
Win Aung
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Free Convection ◽  
Critical Region ◽  
Convection Heat Transfer ◽  
Fluid Temperature ◽  
Bulk Fluid ◽  
Free Convection Heat ◽  
Temperature And Pressure ◽  
Convection Correlation

The free-convection heat transfer from a 0.015-in-dia horizontal platinum wire to carbon dioxide in its critical region is experimentally investigated. The bulk fluid temperature and pressure are varied from 48 deg F to 136 deg F and 1000 psia to 1300 psia, respectively. Wire temperatures up to 1600 deg F are used. The results do not show the sharp rise in the heat flux curves that has been reported in a recent investigation. From the present measurements it appears that the usual free-convection correlation can be used even near the critical state, providing the properties are suitably evaluated.

Tire Bead Overheating in Urban Buses and Trucks Using Drum Brake Systems

1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Energy ◽  
Structural Integrity ◽  
Experimental Temperature ◽  
Temperature Profiles ◽  
Element Analysis ◽  
Drum Brake ◽  
Fea Model

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.

AN EXPERIMENTAL AND NUMERICAL STUDY OF HEAT TRANSFER IN A SIMULATED COLLECTOR FOR A SOLAR DRYER

1993 ◽  
Vol 17 (2) ◽  
pp. 145-160
Author(s):  
P.H. Oosthuizen ◽  
A. Sheriff
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Local Heat Transfer ◽  
Lower Surface ◽  
Local Heat ◽  
Electrical Heating ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Transfer Rates ◽  
Thermocouple Probe

Indirect passive solar crop dryers have the potential to considerably reduce the losses that presently occur during drying of some crops in many parts of the “developing” world. The performance so far achieved with such dryers has, however, not proved to be very satisfactory. If this performance is to be improved it is necessary to have an accurate computer model of such dryers to assist in their design. An important element is any dryer model is an accurate equation for the convective heat transfer in the collector. To assist in the development of such an equation, an experimental and numerical study of the collector heat transfer has been undertaken. In the experimental study, the collector was simulated by a 1m long by 1m wide channel with a gap of 4 cm between the upper and lower surfaces. The lower surface of the channel consisted of an aluminium plate with an electrical heating element, simulating the solar heating, bonded to its lower surface. Air was blown through this channel at a measured rate and the temperature profiles at various points along the channel were measured using a shielded thermocouple probe. Local heat transfer rates were then determined from these measured temperature profiles. In the numerical study, the parabolic forms of the governing equations were solved by a forward-marching finite difference procedure.

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