TY - JOUR
T1 - Effect of small roughness elements on thermal statistics of a turbulent boundary layer at moderate Reynolds number
AU - Doosttalab, Ali
AU - Araya, Guillermo
AU - Newman, Jensen
AU - Adrian, Ronald
AU - Jansen, Kenneth
AU - Castillo, Luciano
PY - 2015/12/8
Y1 - 2015/12/8
N2 - A zero-pressure-gradient turbulent boundary layer flowing over a transitionally rough surface (24-grit sandpaper) with k+∼11 and a momentum-thickness Reynolds number of approximately 2400 is studied using direct numerical simulation (DNS). Heat transfer between the isothermal rough surface and the turbulent flow with molecular Prandtl number Pr=0.71 is simulated. The dynamic multiscale approach developed by Araya et al. (J. Fluid Mech., vol. 670, 2011, pp. 581-605) is employed to prescribe realistic time-dependent thermal inflow boundary conditions. In general, the rough surface reduces mean and fluctuating temperature profiles with respect to the smooth surface flow when normalized by Wang & Castillo (J. Turbul., vol. 4, 2003, 006) inner/outer scaling. It is shown that the Reynolds analogy does not hold for y+
AB - A zero-pressure-gradient turbulent boundary layer flowing over a transitionally rough surface (24-grit sandpaper) with k+∼11 and a momentum-thickness Reynolds number of approximately 2400 is studied using direct numerical simulation (DNS). Heat transfer between the isothermal rough surface and the turbulent flow with molecular Prandtl number Pr=0.71 is simulated. The dynamic multiscale approach developed by Araya et al. (J. Fluid Mech., vol. 670, 2011, pp. 581-605) is employed to prescribe realistic time-dependent thermal inflow boundary conditions. In general, the rough surface reduces mean and fluctuating temperature profiles with respect to the smooth surface flow when normalized by Wang & Castillo (J. Turbul., vol. 4, 2003, 006) inner/outer scaling. It is shown that the Reynolds analogy does not hold for y+
KW - turbulent boundary layers
KW - turbulent flows
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U2 - 10.1017/jfm.2015.676
DO - 10.1017/jfm.2015.676
M3 - Article
AN - SCOPUS:84949599366
VL - 787
SP - 84
EP - 115
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
SN - 0022-1120
ER -