Outer shear layer characteristics of a radially expanding wall jet on smooth and dimpled surfaces

Large eddy simulation and self-similarity analysis of the momentum spreading in the near field region of turbulent submerged round jets

“…The analytical solutions are in good agreement with the LES numerical results at all Reynolds numbers, showing that the axial velocity profile is a selfsimilar function of the variable η in the URF. The analytical solutions are also in good agreement with the experimental results of van Hout et al (2018). 8 is it possible to infer that the ratio between the radial and the axial velocity is of the order of 1 2 Re x .…”

“…Three new self-similar laws are proposed to describe the flow evolution in the NFR, one for the initial region, called Undisturbed Region of Flow, (URF), and two for the final region, the potential core region (PCR). The numerical results presented in this work are also validated with the self-similar laws for the FDR proposed by Tollmien (1926) and Görtler (1942), and the experimental data of Hussein et al, (1994), andPanchapakesan &Lumley, (1993), in the FDR; those of Davies et al (1963), in the PCR;and van Hout et al (2018), in the URF. The conclusion is that previous inability to find the self-similarity law in the NFR is due to the attempt to find a unique self-similar variable to describe the momentum spreading in both the URF and the PCR.…”

Further results on the mean mass transfer and fluid flow in a turbulent round jet

“…On the other hand, the mean passive scalar contours of [26] are more homogenous in PCR and FDR because turbulent Schmidt number is not constant and mean passive scalar is more diffuse, compared to mean axial velocity, because turbulent Schmidt number is smaller than 1. The self-similar mean axial velocity profiles, reported in [32], are in good agreement with [44] in URF, [45] in PCR and [11,[46][47] in FDR. Mean radial velocity contours are in Fig.…”

The Wall-Jet Region of a Turbulent Jet Impinging on Smooth and Rough Plates

“…Other studies experimentally investigate impinging jets to determine the effects of surface roughness on heat transfer (Nevin 2011) or on noise generation (Dhamanekar and Srinivasan 2014). On the other hand, other works focus more specifically on engineered rough surfaces, mostly designed with the objective of maximizing the heat transfer of the configuration (Nagesha et al 2020;Van Hout et al 2018). Relatively few investigations in the literature report direct numerical simulations (DNS) of impinging jet configurations, and most of them limit the study to smooth impingement plates (Dairay et al 2015;Wilke and Sesterhenn 2017;Magagnato et al 2021).…”