Pressure- and buoyancy-driven thermal convection in a rectangular enclosure

Spradley, L. W.; Churchill, Stuart W.

doi:10.1017/s0022112075002303

Cited by 48 publications

(25 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The boundary-layer variables near x = 0 can be written as T= T, p=~, p=p, x={l/2z, u=~l/2a (10) where the scalings have been chosen to produce a balance of conductive and convective energy transport. Then (1) (r (11) …”

Section: A the Boundary Layermentioning

confidence: 99%

“…Heat addition at the wall causes the boundary-layer gas to expand into the container with a speed of O(, 1/2) as given in (10). The outer edge of the expanding boundary layer acts like a variable-speed piston, thus generating a similar mechanical disturbance in the core.…”

Section: B the Corementioning

confidence: 99%

“…Larkin [7], Thuraisamy [8], Spradley et al [9] and Spradley and Churchill [10] have computed the gas motion induced in a slab-like container when the temperature on one-boundary is raised impulsively while the other is held at the initial temperature of the system. The general nonlinear conservation equations, ignoring viscous dissipation, are used as the basis of the study.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The response of a confined gas to a thermal disturbance: rapid boundary heating

Radhwan

Kassoy

1984

J Eng Math

View full text Add to dashboard Cite

Summa~An inert compressible gas confined between infinite parallel planar walls is subjected to significant heat addition at the boundaries. The wall temperature is increased during an interval which is scaled by the acoustic time of the container, defined as the passage time of an acoustic wave across the slab. On this time scale heat transfer to the gas occurs in thin conductive boundary layers adjacent to the walls. Temperature increases in these layers cause the gas to expand such that a finite velocity exists at the boundary-layer edge. This mechanical effect, which is like a time-varying piston motion, induces a planar linear acoustic field in the basically adiabatic core of the slab. A spatially homogeneous pressure rise and a bulk velocity field evolve in the core as the result of repeated passage of weak compression waves through the gas. Eventually the thickness of the conduction boundary layers is a significant fraction of the slab width. This occurs on the condition time scale of the slab which is typically a factor of 106 larger than the acoustic time. The further evolution of the thermomechanical response of the gas is dominated by a conductive-convective balance throughout the slab. The evolving spatially-dependent temperature distribution is affected by the homogeneous pressure rise (compressive heating) and by the deformation process occurring in the confined gas. Superimposed on this relatively slowly-varying conduction-dominated field is an acoustic field which is the descendent of that generated on the shorter time scale. The short-time-scale acoustic waves are distorted as !hey propagate through a slowly-varying inhomogeneous gas in a finite space. Solutions are developed in terms of asymptotic expansions valid when the ratio of the acoustic to conduction time scales is small. The results provide an explicit expression for the piston analogy of boundary heat addition.

show abstract

Section: A the Boundary Layermentioning

confidence: 99%

Section: B the Corementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The response of a confined gas to a thermal disturbance: rapid boundary heating

Radhwan

Kassoy

1984

J Eng Math

View full text Add to dashboard Cite

show abstract

“…Larkin [5] subsequently derived a more general numerical solution for a finite region and showed that Rayleigh's solution for such a region is in serious error quantitatively. Heinmiller [6], Thuraisamy [7], Spradley and Churchill [8], and Ozoe et al [9, 101 also developed numerical solutions. All these numerical solutions are in reasonable agreement for the one common set of conditions.…”

Section: Introductionmentioning

confidence: 99%

Transient behaviour of an impulsively heated fluid

Brown

Churchill

1993

Chem Eng & Technol

View full text Add to dashboard Cite

Approximate as well as reasonably exact numerical solutions of the equation of conservation have previously predicted that sudden heating of a solid surface adjacent to a region of gas will generate a slightly supersonic wave with small positive amplitudes in pressure, temperature and density, and thereby a small mass velocity in the direction of wave propagation. If the gas is confined by a second parallel surface, the wave is predicted to be reflected repeatedly from both surfaces and to decay slowly due to viscous and thermal dispersion. This process, which has been termed thermoacoustic convection, is presumed to result in transient heating of the confined gas and heat transfer through it at rates greatly exceeding that of pure thermal conduction. The current work constitutes the first quantitative experimental confirmation of this behaviour. Numerical solutions obtained for support and guidance of the experimental work define for the first time the conditions required for the generation of a wave of significant strength.

show abstract

“…At present, interest in TAW is primarily due to the possibility of using them as one of the mechanisms of energy transfer. Brief reviews of the most meaningful studies in the field of thermoacoustic convection may be found in [1,2].…”

Section: Introductionmentioning

confidence: 99%