A numerical investigation of the mean wall shear stress properties on a spatially developing turbulent boundary layer over a smooth flat plate was carried out by means of a zonal detached eddy simulation (ZDES) technique for the Reynolds number range 3060 Re θ 13 650. Some asymptotic trends of global parameters are suggested. Consistently with previous findings, the calculation confirms the occurrence of very large-scale motions approximately 5δ to 6δ long which are meandering with a lateral amplitude of 0.3δ and which maintain a footprint in the near-wall region. It is shown that these large scales carry a significant amount of Reynolds shear stress and their influence on the skin friction, denoted C f ,2 , is revisited through the FIK identity by Fukagata, Iwamoto & Kasagi (Phys. Fluids, vol. 14, 2002, p. L73). It is argued that C f ,2 is the relevant parameter to characterize the high-Reynolds-number turbulent skin friction since the term describing the spatial heterogeneity of the boundary layer also characterizes the total shear stress variations across the boundary layer. The behaviour of the latter term seems to follow some remarkable self-similarity trends towards high Reynolds numbers. A spectral analysis of the weighted Reynolds stress with respect to the distance to the wall and to the wavelength is provided for the first time to our knowledge and allows us to analyse the influence of the largest scales on the skin friction. It is shown that structures with a streamwise wavelength λ x > δ contribute to more than 60 % of C f ,2 , and that those larger than λ x > 2δ still represent approximately 45 % of C f ,2 .

A method for generating inflow conditions for large eddy simulations (LESs) of spatially developing turbulent boundary layers is presented. It is an adaptation of the synthetic eddy method (SEM) of Jarrin et al. [Int. J. Heat Fluid Flow 27, 585 (2006)], which uses the Cholesky decomposition of the Reynolds stress tensor to enforce second-order moments starting from a normalized stochastic velocity signal, the latter being constructed with a superimposition of turbulent structures with prescribed geometrical shape and random signs and position. The present method modifies the definition of the stochastic signal so that it can be split into several modes, with different time, length and velocity scales and also with different vorticity contents. The idea is to reproduce more realistically the distribution of scales in the wall-normal direction of a turbulent boundary layer flow. The novelty of the proposed modified SEM is that physical information concerning the coherent vortical structures of such flows are extracted from the literature and used in the definition of the modes. It is shown that the specification of realistic modes for the buffer and the logarithmic layers significantly helps to reduce the spatial transient undergone by the synthetic inflow data. The new method is assessed in the framework of LES and compared to the original SEM and to a reference simulation which uses the recycling procedure of Lund et al. [J. Comput. Phys. 140, 233 (1998)]. First- and second-order statistical results, as well as instantaneous behavior of turbulence, are shown to be in excellent agreement with the reference after an adaptation distance of five to six initial boundary layer thicknesses.

The authors hypothesized that both narcissism and high selfesteem are associated with positive self-views but each is associated with positivity in different domains of the self. Narcissists perceive themselves as better than average on traits reflecting an agentic orientation (e.g., intellectual skills, extraversion) but not on those reflecting a communal orientation (e.g., agreeableness, morality). In contrast, high-self-esteem individuals perceive themselves as better than average both on agentic and communal traits. Three studies confirmed the hypothesis. In Study 1, narcissists rated themselves as extraverted and open to experience but not as more agreeable or emotionally stable. High-selfesteem individuals rated themselves highly on all of these traits except openness. In Study 2, narcissists (but not high-self-esteem individuals) rated themselves as better than their romantic partners. In Study 3, narcissists rated themselves as more intelligent, but not more moral, than the average person. In contrast, highself-esteem individuals viewed themselves as more moral and more intelligent.

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