THE TEMPERATURE DISTRIBUTION PRODUCED BY ACOUSTIC ABSORPTION: I. MACROSCOPIC TREATMENT

1966 ◽  
Vol 44 (12) ◽  
pp. 3001-3011 ◽  
Author(s):  
S. Simons
Keyword(s):  
Temperature Distribution ◽  
Acoustic Wave ◽  
Numerical Results ◽  
Time Dependent ◽  
Acoustic Absorption ◽  
Space And Time

A calculation is given of the temperature distribution in space and time produced by the absorption of an acoustic wave propagated inside a medium, under conditions in which the situation may be described macroscopically. The problem is considered for various geometries, and for both constant and time-dependent energies of the incident acoustic wave. Numerical results are obtained, and a discussion is given of their relevance to various experiments.

A time-dependent model for high-pressure discharges in narrow ablative capillaries

1993 ◽  
Vol 50 (1) ◽  
pp. 51-70 ◽  
Author(s):  
D. Zoler ◽  
S. Cuperman ◽  
J. Ashkenazy ◽  
M. Caner ◽  
Z. Kaplan
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Time Dependent ◽  
Dimensional Model ◽  
Plasma Sources ◽  
One Dimensional ◽  
Space And Time ◽  
Dependent Model ◽  
Energy Equations ◽  
Time Dependent Model

A time-dependent quasi-one-dimensional model is developed for studying high- pressure discharges in ablative capillaries used, for example, as plasma sources in electrothermal launchers. The main features of the model are (i) consideration of ablation effects in each of the continuity, momentum and energy equations; (ii) use of a non-ideal equation of state; and (iii) consideration of space- and time-dependent ionization.

scholarly journals Thermomechanical coupling of ice flow with the bedrock

2003 ◽  
Vol 37 ◽  
pp. 390-396 ◽  
Author(s):  
Richard C.A. Hindmarsh
Keyword(s):  
Temperature Distribution ◽  
Horizontal Velocity ◽  
Time Dependent ◽  
Thermomechanical Coupling ◽  
Positive Anomaly ◽  
Thermal Coupling ◽  
Steady Temperature ◽  
Ice Flow ◽  
Time Dependent Problem ◽  
Geomorphological Processes

AbstractTwo aspects of thermal coupling with bedrock are considered: the coupled time-dependent problem of co-evolving temperatures in lithosphere and ice; and the influence of basal topography on steady temperature distribution within the ice. The nature of the time-dependent coupling is found to depend on the horizontal velocity. As has been suggested, there is a cooling of steady temperatures on bedrock highs, but this is phase-shifted downstream when horizontal velocities increase. This observation may have consequences for geomorphological processes such as plucking and protection. The effect of bedrock channelling on steady temperature is considered. The positive anomaly of basal temperature due to channelling increases as the transverse wavelength decreases, but not monotonically, reaching a plateau when both the wavelengths of the basal topography are around 100 km.

Numerical Experiments of Coolant Mixing in a Lower Plenum of PWR Under Asymmetric Thermal- Hydraulics Conditions

2006 ◽  
Author(s):  
Masanori Ohtani ◽  
Akito Kozuru ◽  
Yasuyuki Kashimoto ◽  
Mitsuto Montani ◽  
Koutaro Takeda ◽  
...  
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Turbulent Mixing ◽  
Numerical Experiments ◽  
Time Dependent ◽  
Inlet Temperature ◽  
Velocity Fluctuations ◽  
The Core ◽  
State Calculation ◽  
Lower Temperature

Asymmetric thermal-hydraulic conditions among primary loops during a postulated steam line break (SLB) induce a non-uniform temperature distribution at a core inlet. When coolant of lower temperature intrudes into a part of core, it leads to a reactivity insertion and a local power increase. Therefore, an appropriate model for the core inlet temperature distribution is required for a realistic SLB analysis. In this study, numerical experiments were conducted to examine the core inlet temperature distribution under the asymmetric thermal-hydraulic coolant conditions among primary loops. 3D steady-state calculations were carried out for Japanese standard Pressurized Water Reactor (PWR) such as 2, 3, 4 loop types and an advanced PWR. Since the flow in a reactor vessel involves time-dependent velocity fluctuations due to a high Reynolds number condition and a complicated geometry of flow path, the turbulent mixing might be enhanced. Hence, the turbulent thermal diffusivity for the steady-state calculation was examined based on experimental results and another transient calculation. As a result, it was confirmed that (1) the turbulent mixing in a downcomer and a lower plenum were enhanced due to time-dependent velocity fluctuations and therefore the turbulent thermal diffusivity for steady-state calculation was specified to be greater, (2) the core inlet temperature distribution predicted by a steady-state calculation reasonably agreed with a experimental data, (3) the patterns of core inlet temperature distribution were comprehended to be dependent on the plant type, i.e. the number of primary loop and (4) under a low flow rate condition, the coolant of lower temperature appeared on the opposite side of the affected loop due to the effect of a natural convection.

scholarly journals Flow of a Jeffrey Fluid Between Two Long Vertical Thin Plates with Porous Medium

2018 ◽  
Vol 7 (4.10) ◽  
pp. 1059
Author(s):  
S. Sreenadh ◽  
B. Govindarajulu ◽  
A. N.S. Srinivas ◽  
R. Nageshwar Rao
Keyword(s):  
Porous Medium ◽  
Temperature Distribution ◽  
Fluid Velocity ◽  
Numerical Results ◽  
Thin Plates ◽  
Jeffrey Fluid ◽  
Runge Kutta Method ◽  
Fluid Parameter ◽  
Permeability Parameter ◽  
Order Four

The present study investigates fully developed free - convection Jeffrey fluid flow between two vertical plates with porous medium. The vertical plates are moving with same velocity but in opposite directions. The coupled nonlinear governing equations are solved by using the linearization technique. The solutions for velocity distribution, temperature distribution, skin friction and rate of heat transfer is obtained in the presence of porous medium by Iterative procedure.  Shooting technique with Runge - Kutta method of order four is proposed to compare the numerical results for velocity and temperature distribution. The numerical results obtained by both methods are compared and presented graphically. It is observed that an increase in the permeability parameter causes decrease in the fluid velocity and an increase in the Jeffrey fluid parameter causes an enhancement in the fluid velocity. The significance of various pertinent parameters like Grashof number, Prandtl number, Eckert number and the plate velocity are explained through graphs.  

Extending UML for Space- and Time-Dependent Applications

2011 ◽  
Author(s):  
Rosanne Price ◽  
Nectaria Tryfona ◽  
Christian S. Jensen
Keyword(s):  
Time Dependent ◽  
Space And Time
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