Heat transfer coefficients for the laminar fully developed flow of viscoplastic liquids through annuli

Farias, Maria Helena; Braga, Carlos Valois Maciel; Mendes, Paulo R. de Souza

doi:10.1016/j.ijheatmasstransfer.2009.02.008

“…Upper Values e (m) e = 0.01 e = ∞ Microelectronics cooling device [25] Space vehicle technology, ball bearing [26] L(m) L → 0 Gas turbine discs cooling [27] L > 0 Heat recovery of burners [28] ω(rpm) ω = 50-114 ω = 30, 000 Bioreactor for culture cells [29] CO 2 turbine diffuser [4] Angle ϕ( • ) 0 ≤ ϕ < 90 Double-pipe heat exchanger [19] ϕ = 90 Vertical thermal energy storage tank [30] ∂T/∂r ( • C/m) −1 Geostrophic motion [31] +1 Most of the applications [14,15] Φ v , Φ w (−) 0.01 < Φ v < 0.1 0.006 < Φ w < 0.2 Al 2 O 3 /water Nanofluids [19] Viscoplastic type fluid [32] While important reviews have been conducted on simple annular geometry without a rotating effect for a double-pipe heat exchanger application [19,33], there are, according to our knowledge, no reviews that focus on the heat transport in rotating annular ducts. The benefits of this review are to reach triple objectives covering the theory development, the applications and the modelling aspects.…”

Section: Control Parameters Lower Valuesmentioning

confidence: 99%

Heat Transport in Rotating Annular Duct: A Short Review

Piton

¹

,

Huchet

²

,

Cazacliu

³

et al. 2022

Energies

6

0

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Heat transport in rotating processes finds a wide range of application in which academic issues in the fluid mechanics and heat transfer areas are here reported. This paper discusses successive works from the seminal paper of Taylor (1923) to recent numerical results established from a broad range of methods such as DNS, LES, RANS or LB methods. The flow regimes identification is thus reported in Taylor–Couette geometry. The role of the axial flow rates in the apparition, stabilization and destruction of the large-scale of the turbulent structures is depicted in the case of Taylor–Couette–Poiseuille geometry. In a non-isothermal condition, a discussion is held on the various exponent values found in the scaling relationships relying on the Nusselt number as a function of the Rayleigh or Reynolds numbers according to the regimes of thermal convection.

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“…Therefore, majority of the observations heavily rely on computational methods. Although a large body of literature has sought to provide experimental data for pure natural (for example Beckmann (1931), Liu et al (1961), Grigull and Hauf (1966), Kuehn and Goldstein (1976), and Fahy et al (2018)) and forced convection (Brighton (1963), Farias et al (2009) and Hosseini et al (2009) among others), mixed type of convection in the turbine casing cavities has not been previously assessed to a broad extent. The experimental investigations concerning the mixed type type of flows have been mostly on fully developed duct and pipe flows (for example Kotake and Hattori (1985), Ciampi et al (1987) and Mohammed et al (2010)).…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigations of mixed convection in turbine cavities for more flexible operations

Murat

¹

,

Rosic

²

,

Tanimoto

³

et al. 2022

J. Glob. Power Propuls. Soc.

1

0

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Since the renewable sources, which have gained great attention due to the low-carbon policies, are inherently intermittent, the conventional power generation systems will be in use to meet the power demand. These systems, however, must be capable of operating along with renewables, which will lead to a need for more operational flexibility with frequent system ramps. Therefore, understanding and control of thermal stresses and clearances are essential for improving flexibility of conventional power plants. Computational fluid dynamics tools are of great importance in predicting the turbomachinery flows design since the direct measurements of detailed and spatial flow and temperature distribution are often not trivial in the real engines. During shut-down regimes of steam turbines, natural convection takes place along with relatively weak forced convection which is not strong enough to prevent a rising thermal plume leading to a non-uniform cooling in the turbine cavities. Although natural and forced convection have been studied separately in the literature, mixed type of flows in turbine cavities have not been investigated extensively. This paper provides unique experimental data set for validation and development of the predictive tools, which is generated from the detailed flow field measurements in a test facility designed for mixed type of flows in the turbine casing cavities with engine representative conditions. Additionally, large eddy simulations have been performed and validated against the generated experimental data, to gain deeper insight into the flow field. Thus, this paper offers a great insight in these complex flow interactions and unique experimental data for enabling the flexible operations and the development of advanced turbulence modelling.

show abstract

“…Therefore, majority of the observations heavily rely on computational methods. Although a large body of literature has sought to provide experimental data for pure natural (for example Beckmann (1931) ; Liu et al (1961) ; Grigull and Hauf (1966); Kuehn and Goldstein (1976) ; Fahy et al (2018)) and forced convection ( Brighton (1963) ; Farias et al (2009) ; Hosseini et al (2009) among others), mixed type of convection in the turbine casing cavities has not been previously assessed to a broad extent. The experimental investigations concerning the mixed type type of flows have been mostly on fully developed duct and pipe flows (for example Kotake and Hattori (1985); Ciampi et al (1987) ; Mohammed et al (2010)).…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Investigations of Mixed Convection in Turbine Cavities for More Flexible Operations

Murat*¹,

Rosic²,

Tanimoto³

et al. 2022

Proceedings of Global Power &Amp; Propulsion Society

0

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Since the renewable sources, which have gained great attention due to the low-carbon policies, are inherently intermittent, the conventional power generation systems will be in use to meet the power demand. These systems, however, must be capable of operating along with renewables, which will lead to a need for more operational flexibility with frequent system ramps. Therefore, understanding and control of thermal stresses and clearances are essential for improving flexibility of conventional power plants. Computational fluid dynamics tools are of great importance in predicting the turbomachinery flows design since the direct measurements of detailed and spatial flow and temperature distribution are often not trivial in the real engines. During shut-down regimes of steam turbines, natural convection takes place along with relatively weak forced convection which is not strong enough to prevent a rising thermal plume leading to a non-uniform cooling in the turbine cavities. Although natural and forced convection have been studied separately in the literature, mixed type of flows in turbine cavities have not been investigated extensively. This paper provides unique experimental data set for validation and development of the predictive tools, which is generated from the detailed flow field measurements in a test facility designed for mixed type of flows in the turbine casing cavities with engine representative conditions. Additionally, large eddy simulations have been performed and validated against the generated experimental data, to gain deeper insight into the flow field. Thus, this paper offers a great insight in these complex flow interactions and unique experimental data for enabling the flexible operations and the development of advanced turbulence modelling.

show abstract

Heat transfer coefficients for the laminar fully developed flow of viscoplastic liquids through annuli

Cited by 13 publications

References 21 publications

Heat Transport in Rotating Annular Duct: A Short Review

Heat Transport in Rotating Annular Duct: A Short Review

Experimental and numerical investigations of mixed convection in turbine cavities for more flexible operations

Experimental and Numerical Investigations of Mixed Convection in Turbine Cavities for More Flexible Operations

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