New sample carrier systems for thermogravimetric analysis under forced flow conditions and their influence on microkinetic results

2015 ◽  
Vol 86 (9) ◽  
pp. 095104 ◽  
Author(s):  
C. Seibel ◽  
T. M. Fieback
Keyword(s):  
Thermogravimetric Analysis ◽  
Forced Flow ◽  
Flow Conditions ◽  
Carrier Systems ◽  
Sample Carrier

R404A condensing under forced flow conditions inside smooth, microfin and cross-hatched horizontal tubes

2003 ◽  
Vol 26 (4) ◽  
pp. 433-441 ◽  
Author(s):  
C.A. Infante Ferreira ◽  
T.A. Newell ◽  
J.C. Chato ◽  
X. Nan
Keyword(s):  
Forced Flow ◽  
Flow Conditions ◽  
Horizontal Tubes

scholarly journals Thermal Examination of a Simplified Exhaust Tube-Heatshield Model

2018 ◽  
Vol 47 (3) ◽  
pp. 190-195 ◽  
Author(s):  
Balázs Vehovszky ◽  
Tamás Jakubík ◽  
Marcell Treszkai
Keyword(s):  
Natural Convection ◽  
Cross Flow ◽  
Exhaust System ◽  
Thermal Conditions ◽  
Forced Flow ◽  
Flow Conditions ◽  
Visualization Technique ◽  
Cfd Simulations ◽  
Critical Part ◽  
Parking Place

Exhaust system and its surrounding is a thermally highly critical part of a vehicle: during forced operation, hottest elements can reach 600 °C. The thermal conditions turn to even more critical if the forced flow leaves off – e.g. when the car stops at a highway parking place. In such a case not only the cooling effect of cross-flow disappears, but the natural convection starts to bring heat toward nearby elements – resulting potential overheating of concerned parts. A measurement setup for modelling such case was built, and different parameters were examined, which have influence on the heating of aluminium heatshield above the exhaust tube. Measurements were complemented by CFD simulations and flow visualization technique aiming the better understanding of evolving thermal and flow conditions.

Crevice Boiling in Steam Generators

1987 ◽  
Vol 109 (3) ◽  
pp. 761-767 ◽  
Author(s):  
S. Tieszen ◽  
H. Merte ◽  
V. S. Arpaci ◽  
S. Selamoglu
Keyword(s):  
Power Plants ◽  
Heated Surface ◽  
Nucleate Boiling ◽  
Forced Flow ◽  
High Speed Photography ◽  
Flow Conditions ◽  
Steam Generators ◽  
Pressurized Water ◽  
Support Plate ◽  
Primary Fluid

Experimental results are presented on the influence of confinement (normal to heated surface) on nucleate boiling in forced flow. The forced flow conditions and confinement geometry studied are similar to those found for boiling between a primary-fluid tube and a tube-support plate in steam generators of pressurized-water-reactor nuclear power plants. Visual observations of the boiling process within the confined region (crevice) between the tube and its support plate, obtained by high-speed photography, are related to simultaneous two-dimensional temperature maps of the hot primary-fluid-tube surface. The results demonstrate the existence of three confinement-dependent boiling regimes in forced flow conditions that are similar to those found in pool boiling conditions. These regimes are shown to be associated with the Weber number.

A Numerical Study of Assisting and Opposing Mixed Convective Heat Transfer From a Horizontal Isothermal High Aspect Ratio Rectangular Cylinder

2012 ◽  
Author(s):  
Patrick H. Oosthuizen
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Numerical Study ◽  
Rectangular Cross Section ◽  
Boussinesq Approximation ◽  
Forced Flow ◽  
Width Ratio ◽  
Flow Conditions ◽  
Rectangular Cylinder

Mixed convective heat transfer from an isothermal cylinder with a rectangular cross-section and a relatively large height-to-width ratio has been numerically studied. The axis of the cylinder is horizontal with the longer sides of the rectangular cylinder being vertical. There is a vertical forced flow over the cylinder. The flow conditions considered are such that in general mixed forced and natural convective flow exists. Both the case where the buoyancy forces act in the same direction as the forced flow (assisting flow) and the case where they act in the opposite direction to the forced flow (opposing flow) have been considered. The flow has been assumed to be two-dimensional and the Boussinesq approximation has been adopted. Attention has been restricted to the flow of air and results have therefore been obtained for a Prandtl number of 0.74. The flow conditions considered are such that laminar or turbulent flow can exist. The main attention is this work has been directed at determining the effect of the flow parameters on the mean heat transfer rate from the cylinder and on determining the conditions under which the flow can be assumed to be forced convective and under which it can be assumed to be natural convective.

Unsteady-State Solidification under Forced Flow Conditions

2007 ◽  
Vol 561-565 ◽  
pp. 991-994 ◽  
Author(s):  
A.N. Turchin ◽  
Dmitry G. Eskin ◽  
Laurens Katgerman
Keyword(s):  
Computer Simulations ◽  
Solidification Front ◽  
Forced Flow ◽  
Structure Evolution ◽  
Unsteady State ◽  
Flow Conditions ◽  
Flow Parameters ◽  
Flow Phenomena ◽  
Solidification Parameters ◽  
Interacting Features

The interaction between flow and progressing solidification front is of great importance, since it occurs in all casting processes. The present paper provides a better understanding of the flow phenomena and associated complex effects on solidification in a rectangular cavity under forced flow conditions, by means of experiments and computer simulations. It is shown that the cavity-driven flow with solidification is determined by several interacting features. The variation in bulk flow velocity and initial superheat dramatically changes the macro- and microstructure, promoting grain refinement, formation of peculiar grain and dendrite morphologies, etc. In particular, twinned feathery grains are found in the structure formed under certain heat and flow conditions during solidification. Some correlations between twinned feathery morphology, flow and solidification parameters are obtained. The effect of flow vortices on progressing solidification front and their effects on structure evolution are analyzed. Finally, the quantitative correlations between microstructure, solidification and flow parameters are established.

scholarly journals Bubbly free and impinging jets under forced flow conditions: experimental study by means of PIV/PFBI

2017 ◽  
Vol 899 ◽  
pp. 032016
Author(s):  
Mikhail Yu Nichik ◽  
Konstantin S Pervunin ◽  
Dmitriy M. Markovich
Keyword(s):  
Experimental Study ◽  
Impinging Jets ◽  
Forced Flow ◽  
Flow Conditions

Single-phase heat transfer regimes in forced flow conditions under exponential heat inputs

2021 ◽  
Vol 174 ◽  
pp. 121294
Author(s):  
F. Chavagnat ◽  
R. Nop ◽  
N. Dorville ◽  
B. Phillips ◽  
M. Bucci
Keyword(s):  
Heat Transfer ◽  
Single Phase ◽  
Forced Flow ◽  
Flow Conditions
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