Numerical Prediction of Wall Temperatures for Near-Critical Para-Hydrogen in Turbulent Upflow Inside Vertical Tubes

Bellmore, C. P.; Reid, R. L.

doi:10.1115/1.3245618

Cited by 36 publications

(22 citation statements)

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“…12,13 Several numerical studies with turbulence models have also been performed for supercritical flows to test the applicability of various turbulence models to heat transfer problems regarding SCP fluids. These studies include Bellmore and Reid, 14 Koshizuka et al, 15 and He et al 16 but their results were not always successful. More advanced computational studies using direct numerical simulation ͑DNS͒ have been recently conducted to investigate the heat transfer at SCP.…”

Section: Introductionmentioning

confidence: 96%

Direct numerical simulation of heated CO2 flows at supercritical pressure in a vertical annulus at Re=8900

2008

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The present study is concerned with thermal physics of the fluid at supercritical pressure ͑SCP͒ where many singular phenomena are observed in turbulent heat transfer due to severe property variations of the fluid. Direct numerical simulation is conducted for upward annular flows of CO 2 at a pressure of 8 MPa with a constant-heat-flux boundary condition imposed on the inner wall. All simulations are made at the inlet bulk Reynolds number of 8900 with particular attention being paid to the structure of the heated boundary layers at SCP. It is shown that most singular phenomena at SCP occur when the pseudocritical temperature arises between the heated wall and bulk fluid temperatures. The mean velocity profile near the heated wall shows no logarithmic distribution in the inertial subrange because a large reduction in the Reynolds shear stress occurs in the viscous region. The computational flow visualization reveals that alternating low-and high-speed streaks in the viscous region are not clearly observed when the wall temperature peak is realized due to significant heat transfer deterioration. These results strongly suggest that the ejection and sweep motions of the fluid in the viscous region become so weakened that turbulent boundary layers at SCP cannot be self-sustained in the presence of strong stabilizing effects of the variable-property and buoyancy. It is also shown that streaky thermal pattern remains no longer similar to that of the velocity boundary layer when these coherent motions are reduced in the viscous region. In the meanwhile, the predicted normalized temperature profile at SCP shows a nearly flat distribution outside the viscous region although substantial amount of the radial turbulent heat flux is predicted there. This singular phenomenon at SCP can be considered as comparable to a phase change phenomenon at subcritical pressure, where the internal energy of the fluid is increased without changing the fluid temperature. At SCP, this transition occurs continuously across the pseudocritical point but the computational flow visualization shows very vigorous density fluctuations when it occurs.

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Section: Introductionmentioning

confidence: 96%

Direct numerical simulation of heated CO2 flows at supercritical pressure in a vertical annulus at Re=8900

2008

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“…As a pioneer work, Bellmore and Reid [17] suggested a modified mixing length model by including density fluctuations into the equations of turbulent transport. The additional terms owing to density fluctuations into the time-averaged turbulent continuity equation added to the difficulty in solving the flow field.…”

Section: Introductionmentioning

confidence: 99%

“…First, based on the assumption that the effects of buoyancy and acceleration are negligible, the convection transport equations for the steady turbulent compressible pipe flows are reduced into the one-dimensional boundary-layer equations and then nondimensionalized. Second, on the basis of the work by Bellmore and Reid [17], a new approach to include density fluctuations in the equations of turbulent transport is suggested, and then a modified mixing length turbulence model is developed for the variable property flow. Finally, with these mathematical models, numerical calculations are performed to simulate the turbulent convective heat transfer of water flowing in round tubes at supercritical pressures.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, many numerical studies on the turbulent convective heat transfer of the supercritical pressure fluids in various flow channels were performed [12,13,[17][18][19][20][21][22][23][24][25][26], especially those recent studies with the help of the commercial CFD code [13,[21][22][23][24][25][26]. The major difficulty in the numerical calculation is the proper selection of the turbulence model.…”

Section: Introductionmentioning

confidence: 99%

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A Novel Model of Turbulent Convective Heat Transfer in Round Tubes at Supercritical Pressures

Mao¹,

Bai²,

Guo³

2011

Heat Transfer Engineering

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In the present study, a novel model was established to investigate the enhanced heat transfer to turbulent pipe flow of supercritical pressure fluids. The governing equations for the steady turbulent compressible pipe flow were simplified into the one-dimensional nondimensionalized forms based on the boundary layer theory. A conventional mixing length turbulence model for constant-property pipe flows was modified by introducing the effect of density fluctuations into the equations of turbulent transport, and the modified turbulence model was applicable to both constant-property and variable-property pipe flows. With the suggested model, which was a combination of the nondimensional governing equations and the modified turbulence model, the numerical calculations were carried out for the turbulent convective heat transfer of water in round tubes at supercritical pressures. The results showed that the present model can provide a relatively precise prediction about the effect of pressure, mass flux, and wall heat flux on heat transfer for supercritical fluid flows and greatly reduce the calculation workload. The modified turbulence model showed a much better agreement with the experimental results than the original turbulence model.

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“…Valueva and Popov [1985] showed that this model resulted in good agreement to subcritical and supercritical flows. On the other hand, Bellmore and Reid [1983] suggested a mixing length model with density fluctuation term, which was derived from the Reynolds-average technique rather than from the Favre-average technique. Lee and Howell [1998] modified this model and showed that their results were in a good agreement with some data.…”

Section: Introductionmentioning

confidence: 99%

Advanced Computational Thermal Fluid Physics (CTFP) and Its Assessment for Light Water Reactors and Supercritical Reactors

McEligot¹,

Condie²,

McCreery³

et al. 2005

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Numerical Prediction of Wall Temperatures for Near-Critical Para-Hydrogen in Turbulent Upflow Inside Vertical Tubes

Cited by 36 publications

References 0 publications

Direct numerical simulation of heated CO2 flows at supercritical pressure in a vertical annulus at Re=8900

Direct numerical simulation of heated CO2 flows at supercritical pressure in a vertical annulus at Re=8900

A Novel Model of Turbulent Convective Heat Transfer in Round Tubes at Supercritical Pressures

Advanced Computational Thermal Fluid Physics (CTFP) and Its Assessment for Light Water Reactors and Supercritical Reactors

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