Stability characteristics of a single-phase free convection loop

Creveling, H. F.; Paz, J.F. de; Baladi, J. Y.; Schoenhals, R. J.

doi:10.1017/s0022112075000171

Cited by 254 publications

(89 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Upon substituting the series (4) and (S) into the governing equations (l)- (3) and requiring that these equations are satisfied in the sense of weighted residuals, we obtain an infinite set of ordinary differential equations. Three equations which are similar to the celebrated Lorenz equations" decouple from the rest of the set (with exact closure) and can be solved independently of the other equations without need of truncation.…”

Section: Mathematical Modelmentioning

confidence: 99%

Active control of convection

Singer¹,

Bau²

1991

Physics of Fluids A: Fluid Dynamics

View full text Add to dashboard Cite

It is demonstrated theoretically that active (feedback) control can be used to alter the characteristics of thermal convection in a toroidal, vertical loop heated from below and cooled from above. As the temperature difference between the heated and cooled sections of the loop increases,t he flow in the uncontrolled loop changes from no motion to steady; time independent motion to temporally oscillatory, chaotic motion. With the use of a feedback controller effecting small perturbations in the boundary conditions, one can maintain the no-motion state at significantly higher temperature differences than the critical one corresponding to the onset of convection in the uncontrolled system. Alternatively, one can maintain steady, time-independent flow under conditions in which the flow would otherwise be chaotic. That is, the controller can be used to suppress chaos. Likewise, it is possible to stabilize periodic nonstable orbits that exist in the chaotic regime of the uncontrolled system. Finally, the controller also can be used to induce chaos in otherwise laminar (fully predictable), nonchaotic flow. It is demonstrated theoretically that active (feedback) control can be used to alter the characteristics of thermal convection in a toroidal, vertical loop heated from below and cooled from above. As the temperature difference between the heated and cooled sections of the loop increases, the flow in the uncontrolled loop changes from no motion to steady; timeindependent motion to temporally oscillatory, chaotic motion. With the use of a feedback controller effecting small perturbations in the boundary conditions, one can maintain the nomotion state at significantly higher temperature differences than the critical one corresponding to the onset of convection in the uncontrolled system. Alternatively, one can maintain steady, time-independent flow under conditions in which the flow would otherwise be chaotic. That is, the controller can be used to suppress chaos. Likewise, it is possible to stabilize periodic nonstable orbits that exist in the chaotic regime of the uncontrolled system. Finally, the controller also can be used to induce chaos in otherwise laminar (fully predictable), nonchaotic flow.

show abstract

Section: Mathematical Modelmentioning

confidence: 99%

Active control of convection

Singer¹,

Bau²

1991

Physics of Fluids A: Fluid Dynamics

View full text Add to dashboard Cite

show abstract

“…They predicted oscillatory modes which could be long-lived during periods of high hot water draw from the tank--i.e., during periods when the system was significantly perturbed by the hot water draw. Furthermore, there have been numerous theoretical predi ions and experimental observations of fluid flow oscillations in non-solar natural convection systems [46][47][48][49][50][51][52][53] An indication of the effect of heat exchanger on system perforrnance is given by Fi • 7(a) and 7(b). In Fig.…”

Section: ~27~mentioning

confidence: 99%

Detailed Loop Model (DLM) analysis of liquid solar thermosiphons with heat exchangers

et al. 1981

View full text Add to dashboard Cite

“…Experiments show that when the difference in temperature between the top and the bottom of the loop is large enough, the fluid exhibits unstable motion which may also be chaotic (see [6,9,10]). We consider the problem of boundary control for this two-dimensional thermal fluid flow problem as in [5].…”

Section: Controller Reduction For Pde Systemsmentioning

confidence: 99%

A Computational Environment for Design of Aerospace Systems

Burns¹

2000

View full text Add to dashboard Cite

show abstract

Stability characteristics of a single-phase free convection loop

Cited by 254 publications

References 4 publications

Active control of convection

Active control of convection

Detailed Loop Model (DLM) analysis of liquid solar thermosiphons with heat exchangers

A Computational Environment for Design of Aerospace Systems

Contact Info

Product

Resources

About