Direct numerical simulation of turbulence in an internally heated convective fluid layer and implications for statistical modelling

Wörner, Martin; Schmidt, Michael A.; Grötzbach, G.

doi:10.1080/00221689709498388

Cited by 28 publications

(32 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Analyses and validation for the IHL are found e.g. in Grötzbach [17,18,21,22], Wörner et al [49], Wörner and Grötzbach [50], and Chandra [4]. A review on the knowledge of the convective heat transfer from the less recognized IHL is given by Kulacki and Richards [28].…”

Section: Dns Specifications and Resultsmentioning

confidence: 97%

“…Further on, the vertical profiles of E 0 depict that at these Ra the convection in the IHL is still in-homogeneous in the vertical direction in the core of the fluid layer, whereas in RBC a wide area is observed in which the energy distribution is homogeneous in x 3 . Data for the terms in the transport equation for E 0 are given for IHL in Grötzbach [21] and Wörner et al [49] and for RBC in Wörner [48]. …”

Section: Dns Specifications and Resultsmentioning

confidence: 99%

“…This is usually employed in the near-wall damping functions. It holds obviously also in IHL because Wörner et al [49] found that some model coefficients in the transport equations for E 0 and for the turbulent heat fluxes have to be increased by large factors in this convection type. Figure 6 indeed indicates that C 0 2 ¼ C 2 Re a t with a =0.8 and 1.5≤C 2 ≤7, Chandra [4].…”

Section: Modification Of a Rans Model Formentioning

confidence: 90%

“…One of the major problems is that it does not account for the counter gradient energy transport which may occur in buoyant flows, see e.g. Lumley et al [34], Moeng and Wyngaard [36], and for IHL in Wörner et al [49]. The DNS results for D E,t are given in Fig.…”

Section: Modeling Requirementsmentioning

confidence: 96%

“…Both are modeled together by means of a gradient-diffusion model, Launder and Spalding [29]. Wörner et al [49] used Direct Numerical Simulation (DNS) data and showed that this standard model is not adequate in IHL. Areas with counter gradient energy fluxes occur which cannot be reproduced by a gradient-diffusion model.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Analysis and Modeling of the Turbulent Diffusion of Turbulent Kinetic Energy in Natural Convection

Chandra

Grötzbach²

2007

Flow Turbulence Combust

Self Cite

View full text Add to dashboard Cite

Buoyant flows often contain regions with unstable and stable thermal stratification from which counter gradient turbulent fluxes are resulting, e.g. fluxes of heat or of any turbulence quantity. Basing on investigations in meteorology an improvement in the standard gradient-diffusion model for turbulent diffusion of turbulent kinetic energy is discussed. The two closure terms of the turbulent diffusion, the velocity-fluctuation triple correlation and the velocity-pressure fluctuation correlation, are investigated based on Direct Numerical Simulation (DNS) data for an internally heated fluid layer and for Rayleigh-Bénard convection. As a result it is decided to extend the standard gradient-diffusion model for the turbulent energy diffusion by modeling its closure terms separately. Coupling of two models leads to an extended RANS model for the turbulent energy diffusion. The involved closure term, the turbulent diffusion of heat flux, is studied based on its transport equation. This results in a buoyancy-extended version of the Daly and Harlow model. The models for all closure terms and for the turbulent energy diffusion are validated with the help of DNS data for internally heated fluid layers with Prandtl number Pr=7 and for Rayleigh-Bénard convection with Pr=0.71. It is found that the buoyancy-extended diffusion model which involves also a transport equation for the variance of the vertical velocity fluctuation gives improved turbulent energy diffusion data for the combined case with local stable and unstable stratification and that it allows for the required counter gradient energy flux.

show abstract

Section: Dns Specifications and Resultsmentioning

confidence: 97%

Section: Dns Specifications and Resultsmentioning

confidence: 99%

Section: Modification Of a Rans Model Formentioning

confidence: 90%

Section: Modeling Requirementsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Analysis and Modeling of the Turbulent Diffusion of Turbulent Kinetic Energy in Natural Convection

Chandra

Grötzbach²

2007

Flow Turbulence Combust

Self Cite

View full text Add to dashboard Cite

show abstract

Internally Heated Convection and Rayleigh-Bénard Convection

Goluskin¹

2016

SpringerBriefs in Applied Sciences and Technology

View full text Add to dashboard Cite

PrefaceThe purpose of this SpringerBrief is to review heat transfer in layers of convective fluid. Six different configurations are considered-three that are versions of Rayleigh-Bénard (RB) convection, which is driven by differential heating at the boundaries, and three that are driven by uniform internal heating. The essential features of all six models are derived mathematically. The experimental literature is reviewed in depth for the models of internally heated (IH) convection, which are much less studied than their RB counterparts. Experiments on RB convection are treated in less depth, as they have been thoroughly reviewed elsewhere.Along with placing the various convective models within a conceptual framework that brings out their similarities, we give some minor results not published elsewhere. For instance, a few of the linear instability and energy stability thresholds given in tables 2.2 and 2.3 either have not been reported before or have been reported with less precision. One of the bounds proven in §2.3 is also new, as are the visualizations of simulations included as figure 1.2.Chapter 1 provides background and then defines the six configurations under study, the governing equations of our models, and their basic features. Chapter 2 presents results that can be derived mathematically from the governing equations: linear and nonlinear stability thresholds of static states, along with proven bounds on mean temperatures and heat fluxes. For the IH cases only, chapter 3 gives a quantitative survey of heat transport in both laboratory experiments and numerical simulations, followed by suggestions for future work.

show abstract

Internally Heated Convection Experiments and Simulations

Goluskin

2015

Internally Heated Convection and Rayleigh-Bénard Convection

View full text Add to dashboard Cite

Direct numerical simulation of turbulence in an internally heated convective fluid layer and implications for statistical modelling

Cited by 28 publications

References 21 publications

Analysis and Modeling of the Turbulent Diffusion of Turbulent Kinetic Energy in Natural Convection

Analysis and Modeling of the Turbulent Diffusion of Turbulent Kinetic Energy in Natural Convection

Internally Heated Convection and Rayleigh-Bénard Convection

Internally Heated Convection Experiments and Simulations

Contact Info

Product

Resources

About