Natural convection due to differential heating of inclined walls and heat source placed on bottom wall of an attic shaped space

Sojoudi, Atta; Saha, Suvash C.; Gu, Yuantong

doi:10.1016/j.enbuild.2014.12.042

Cited by 16 publications

(7 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the total heat loss was also found to be reduced by using plate fins. Further, [3] numerically investigated natural convection heat transfer by subjecting the cavity to differential heating at the inclined walls. The source of heat was placed at the bottom wall and the governing equations were solved with ANSYS Fluent, finite volume-based software.…”

Section: Introductionmentioning

confidence: 99%

Modeling of natural convection of a concentrated solar power receiver absorber tube in interaction with neighbouring absorbers

2021

View full text Add to dashboard Cite

Concentrated Solar Power (CSP) technology stands out among other renewable energy sources not only because of its ability to address current energy security and environmental challenges but because its energy can be stored for future use. To ensure optimum performance in this system, the heat losses need to be evaluated for better design. This work studies the natural convection in the receiver absorber tube of a CSP plant taking into consideration the influence of neighboring absorbers. A 2-Dimensional model was adopted in this study. Initially, a single absorber tube was considered, it was subjected to heat flux at the top wall, the bottom wall was insulated and a temperature differential was set up at the lateral walls. The dimensionless forms of Navier-Stokes and energy equations were solved using the finite element formulation of COMSOL Multiphysics software. The result obtained for a single absorber tube showed good agreement with existing research works. This validated model was then extended to multiple absorber tubes (two to six absorber tubes). On the basis of the study, there is an observed increase in the intensity and dominance of convective heat transfer with an increase in the number of absorber tubes. This is occasioned by an increase in the average surface temperature as well as average Nusselt number. For the Rayleigh number of 104, 105 and 106, the average Nusselt number increases with the number of absorber tubes by 13.87 %, 6.26 %, and 1.55 %, respectively. This increment suggests effect of thermal interactions among the neighboring absorber tubes

show abstract

Section: Introductionmentioning

confidence: 99%

Modeling of natural convection of a concentrated solar power receiver absorber tube in interaction with neighbouring absorbers

2021

View full text Add to dashboard Cite

show abstract

“…The inner wall of it is assumed to be discrete heating and the outer wall is uniformly cooled. Sojoudi et al [21] investigated natural convection heat transfer and flow properties in an attic shaped triangular cavity considering differentially heated inclined walls and a heat source in the middle of the right half of the bottom surface. Later, Sojoudi et al [22] also studied unsteady flow and heat transfer of air due to differentially heating from inclined walls and a heat source at the bottom wall in a triangular cavity.…”

Section: Introductionmentioning

confidence: 99%

Natural convection in a cavity with trapezoidal heat sources mounted on a square cylinder

2020

View full text Add to dashboard Cite

Flow and heat transfer in an enclosed domain bounded by two concentric square cylinders are investigated in the presence of trapezoidal heat sources placed on the inner square cylinder. The governing equations valid for the present geometry are derived using suitable transformations. These are solved employing finite difference method. Numerical results show that the intensity of streamlines and isotherms is significantly augmented upon increasing the number of the heat sources, the width and breadth of the heat sources and the Rayleigh number. Usually, each half of the cavity contains one major vortex which consists of two eddies. However, for larger width or breadth of the heat sources each major vortex consists of three eyes. This remarkable characteristic is identified because of the 2 weak eddies on both sides of a heat source. When the Rayleigh number is relatively high, there exist three vortices in each half of the cavity. Due to the increase of the width and breadth of the heat sources, the Nusselt number at the top of the heat sources decreases whereas the Nusselt number at the outer walls of the cavity is found to increase. Moreover, an increasing Rayleigh number considerably augments the heat transfer through the heat sources and the outer walls of the cavity.

show abstract

“…Natural convection in the triangular container was studied extensively for various industrial applications (Joudi et al , 2004; Oztop et al , 2007; Kent et al , 2007; Oztop et al , 2012; Sun and Pop, 2014; Saha and Gu, 2015; Sojoudi et al , 2015; Rahman et al , 2017; Oztop et al , 2017; Das et al , 2018). A few works are explained next.…”

Section: Introductionmentioning

confidence: 99%

Numerical heat flow visualization analysis on enhanced thermal processing for various shapes of containers during thermal convection

Lukose

Basak

2019

HFF

View full text Add to dashboard Cite

Purpose The purpose of this paper is to study thermal (natural) convection in nine different containers involving the same area (area= 1 sq. unit) and identical heat input at the bottom wall (isothermal/sinusoidal heating). Containers are categorized into three classes based on geometric conﬁgurations [Class 1 (square, tilted square and parallelogram), Class 2 (trapezoidal type 1, trapezoidal type 2 and triangle) and Class 3 (convex, concave and triangle with curved hypotenuse)]. Design/methodology/approach The governing equations are solved by using the Galerkin ﬁnite element method for various processing fluids (Pr = 0.025 and 155) and Rayleigh numbers (103 ≤ Ra ≤ 105) involving nine different containers. Finite element-based heat flow visualization via heatlines has been adopted to study heat distribution at various sections. Average Nusselt number at the bottom wall ( Nub¯) and spatially average temperature (θ^) have also been calculated based on ﬁnite element basis functions. Findings Based on enhanced heating criteria (higher Nub¯ and higher θ^), the containers are preferred as follows, Class 1: square and parallelogram, Class 2: trapezoidal type 1 and trapezoidal type 2 and Class 3: convex (higher θ^) and concave (higher Nub¯). Practical implications The comparison of heat flow distributions and isotherms in nine containers gives a clear perspective for choosing appropriate containers at various process parameters (Pr and Ra). The results for current work may be useful to obtain enhancement of the thermal processing rate in various process industries. Originality/value Heatlines provide a complete understanding of heat flow path and heat distribution within nine containers. Various cold zones and thermal mixing zones have been highlighted and these zones are found to be altered with various shapes of containers. The importance of containers with curved walls for enhanced thermal processing rate is clearly established.

show abstract

Natural convection due to differential heating of inclined walls and heat source placed on bottom wall of an attic shaped space

Cited by 16 publications

References 25 publications

Modeling of natural convection of a concentrated solar power receiver absorber tube in interaction with neighbouring absorbers

Modeling of natural convection of a concentrated solar power receiver absorber tube in interaction with neighbouring absorbers

Natural convection in a cavity with trapezoidal heat sources mounted on a square cylinder

Numerical heat flow visualization analysis on enhanced thermal processing for various shapes of containers during thermal convection

Contact Info

Product

Resources

About