A dynamic thermal insulator: Inducing resonance within a fluid saturated porous medium enclosure heated periodically from the side

Abstract This theoretical and numerical study investigates the natural convection flow within a fluid saturated porous medium enclosure subjected to intermittent heating from the side (hot wall). A theory for predicting the natural convection frequency of the flow wheel circulating inside the enclosure is developed from the general porous medium equations on a scaling basis. Physical insight indicates that heat flow resonance might occur when the input heat frequency matches the flow wheel circulating frequency. Numerical simulations confirm the existence of a preferred (resonance) input heat pulsating frequency. They also reveal that at the resonance frequency the fluid saturated porous medium system behaves as a dynamic thermal insulator in which the strong natural convection activity within the system, characterized by high amplitude heat flow oscillations, coexists with a damped oscillatory heat flux at the isothermal (cold) wall.

[1]  A. Bejan,et al.  The departure from Darcy flow in natural convection in a vertical porous layer , 1985 .

[2]  J. L. Lage,et al.  NONUNIFORM GRID ACCURACY TEST APPLIED TO THE NATURAL-CONVECTION FLOW WITHIN A POROUS MEDIUM CAVITY , 1993 .

[3]  C. L. Tien,et al.  Boundary and inertia effects on flow and heat transfer in porous media , 1981 .

[4]  Adrian Bejan,et al.  The resonance of natural convection in an enclosure heated periodically from the side , 1993 .

[5]  R. Viskanta,et al.  Effect of anisotropic permeability on the transport process during solidification of a binary mixture , 1992 .

[6]  C. E. Hickox,et al.  Application of flux-corrected transport (FCT) to high Rayleigh number natural convection in a porous medium , 1986 .

[7]  P. Cheng,et al.  Heat Transfer in Geothermal Systems , 1979 .

[8]  S. Ergun.  Fluid flow through packed columns , 1952 .

[9]  A. Bejan,et al.  Unsteady natural convection in a porous layer , 1983 .

[10]  S. Armfield,et al.  Direct simulation of wave interactions in unsteady natural convection in a cavity , 1991 .

[11]  N. E. Wijeysundera,et al.  Effects of condensation and liquid transport on the thermal performance of fibrous insulations , 1992 .

[12]  A numerical investigation of phase change effects in porous materials , 1989 .

[13]  A. Bejan,et al.  The horizontal spreading of thermal and chemical deposits in a porous medium , 1987 .

[14]  P. Cheng,et al.  Thermal dispersion in a porous medium , 1990 .

[15]  M. Kazmierczak,et al.  Buoyancy-driven flow in an enclosure with time periodic boundary conditions , 1992 .

[16]  J. L. Lage.  Natural convection within a porous medium cavity: Predicting tools for flow regime and heat transfer , 1993 .

[17]  A. Bejan,et al.  Convection in Porous Media , 1992 .

[18]  J. L. Lage.  On the Theoretical Prediction of Transient Heat Transfer Within a Rectangular Fluid-Saturated Porous Medium Enclosure , 1993 .

[19]  S. Patankar.  Numerical Heat Transfer and Fluid Flow , 2018, Lecture Notes in Mechanical Engineering.

[20]  Steven W. Armfield,et al.  Transient features of natural convection in a cavity , 1990, Journal of Fluid Mechanics.

[21]  J. Skarda.  Thermal modeling with solid/liquid phase change of the thermal energy storage experiment , 1991 .

[22]  C. Hoogendoorn,et al.  On the stability of the natural convection flow in a square cavity heated from the side , 1990 .