Structure of turbulent two-dimensional channel flow with strongly heated wall

Wardana, I.N.G.; Ueda, Toshihisa; Mizomoto, Masahiko

doi:10.1007/bf00208070

Cited by 21 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This leads to the assumption that in the case of the heated surface the intermittent character near the boundary layer edge is shifted to higher values of y/δ 0.99 , which is consistent with the other findings in this paper. It has to be stated that the findings in the present study of the turbulent boundary layer are unlike the behavior of the S f (u)-distribution reported by Wardana et al [29] for …”

Section: Turbulence Intensities Skewness and Flatness Distributionscontrasting

confidence: 79%

“…Note, however, the surface excess temperature was much higher in the experiments of Matsushita et al [21], which could be responsible for the different behavior of the rms fluctuations. In turbulent channel an opposite a b behavior was observed by Wardana et al [29]. At flow with very high surface excess temperatures ( T ≈ 700 K), they measured reduced streamwise velocity fluctuations in a region y/δ 0.99 = 0.2-1, with a vanishing discrepancy at the boundary layer edge.…”

Section: Turbulence Intensities Skewness and Flatness Distributionsmentioning

confidence: 72%

“…The majority of the studies involving only slightly heated surfaces ( T ≤ 20 K) focused on determining heat transfer and skin friction coefficients [3]. Several studies for turbulent channel, duct, and flat plate boundary layer flow with strongly heated surfaces and wall temperatures of up to T = 1,100 K have been conducted by Wardana et al [29,30] and Matsushita et al [21]. With an additional heat flux of q = 50 kW/m 2 and surface temperatures up to T = 973 K the aforementioned authors report no relevant effect of the supplied heat on the development of the mean velocity and temperature profiles.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Measurement in a Zero-Pressure Gradient Turbulent Boundary Layer with Forced Thermal Convection

Große

Schröder

2007

Flow Turbulence Combust

View full text Add to dashboard Cite

A subsonic zero-pressure gradient turbulent boundary layer developing on a uniformly heated surface at a Reynolds number in the range of 3,560 ≤ Re θ ≤ 5,360 was investigated. Particle-image velocimetry measurements were performed at various positions in the streamwise direction for several wind-tunnel speeds and for different wall excess temperatures to show the thermal convection effects to expand the boundary-layer thickness δ 0.99 and to enlarge the turbulence intensities in the log-law and wake region. The mean velocity profiles are found to be self-preserving. The inclination of large-scale ramp-like vortex packets increases to higher characteristic angles, i.e., the mean angles are enlarged by approximately 5-10 • . Hairpin-like vortex structures originating from the near-wall region seem to undergo higher climbing rates in the wall-normal direction causing the above mentioned significant changes in the boundary-layer thickness δ 0.99 and the strongly increased distributions of turbulence intensities in the wake region of the boundary layer. Changes in the distributions of the skewness and flatness of the probability density function (PDF) of the streamwise fluctuations corroborate these findings. The two-point correlation distribution of the streamwise velocity fluctuations R uu is increased for wall distances y/δ 0.99 = 0.1 to y/δ 0.99 = 0.75 indicating the existence of coherent structures in higher regions of the boundary layer.

show abstract

Section: Turbulence Intensities Skewness and Flatness Distributionscontrasting

confidence: 79%

Section: Turbulence Intensities Skewness and Flatness Distributionsmentioning

confidence: 72%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Measurement in a Zero-Pressure Gradient Turbulent Boundary Layer with Forced Thermal Convection

Große

Schröder

2007

Flow Turbulence Combust

View full text Add to dashboard Cite

show abstract

“…was used as a coupling submodel for each elementary gaseous reaction. Measurements in non-catalytic turbulent reacting hydrogen-air boundary layers [27] and in non-reacting turbulent heated channel flows [28] have shown nearly symmetric scalar p.d.f.s, consistent with the Gaussian approach. In this respect, the Gaussian shape is less restrictive compared to open turbulent combustion applications [26].…”

Section: Gas-phase Modellingmentioning

confidence: 53%

“…The peak levels of the intensities ( T 2 ) 1/2 /(T W −T C ) are as high as 7% at x=61 mm and drop downstream. Such intensity levels are typical in turbulent boundary layer combustion [27] or turbulent heat transfer in channels [28]. In addition, the peak rms temperature fluctuations are always located outside the reaction zone.…”

Section: Turbulent Heterogeneous-homogeneous Combustionmentioning

confidence: 92%

Numerical modelling of turbulent catalytically stabilized channel flow combustion

et al. 2000

View full text Add to dashboard Cite

The turbulent catalytically stabilized combustion of lean hydrogen-air premixtures is investigated numerically in plane channels with platinum-coated isothermal walls. The catalytic wall temperature is 1220 K and the incoming mixture has a mean velocity of 15 m/s and a turbulent kinetic energy of 1.5 m 2 /s 2 . A two-dimensional elliptic model is developed with elementary heterogeneous and homogeneous chemical reactions. The approach is based on a two-layer k-ε model of turbulence, a Favre-average moment closure, a presumed-shape (Gaussian) probability density function for gaseous reactions, and a laminar-like closure for surface reactions. Gaseous combustion is confined close to the catalyst surface due to the diffusional imbalance of the limiting reactant (hydrogen). In addition, the peak rms temperature and species fluctuations are always located outside the extent of the homogeneous reaction zone indicating that thermochemical fluctuations have no significant influence on gaseous combustion. Turbulence is significantly suppressed by gaseous combustion resulting in higher turbulent transport for the leaner mixtures, a successive push of the gaseous reaction zone towards the wall, incomplete combustion, and subsequent catalytic conversion of the leaked fuel. Comparison between turbulent and laminar cases having the same incoming properties shows that turbulence inhibits homogeneous ignition due to increased heat transport away from the near-wall layer.

show abstract