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1. Transitional Boundary Layer Data Set

   https://doi.org/10.7281/T17S7KX8  

   Jin, Lee; Tamer, Zaki (January 2018, Johns Hopkins Turbulence Databases)

   Direct numerical simulation (DNS) of a transitional boundary layer over a plate with an elliptical leading edge. Navier-Stokes was discretized on a curvilinear grid and solved using a finite volume DNS code. A fractional-step algorithm was adopted, and the spatial discretization was a staggered volume-flux formulation. The viscous terms were integrated in time implicitly using the Crank-Nicolson and the advections terms were treated explicitly using the Adams-Bashforth. Pressure was treated using implicit Euler in the δp-form. The pressure equation was Fourier transformed in the span, and the resulting Helmholtz equation was solved for every spanwise wavenumber using two-dimensional multi-grid. After the simulation has reached a statistical stationary state, 4701 frames of data, which includes the 3 components of the velocity vector and the pressure, are generated and written in files that can be accessed directly by the database (FileDB system). Since the grid is staggered, data at the wall are not stored in the database. However, JHTDB provides values in the region between the wall and the first grid point, y∈[0, 0.0036], using 4th-order Lagrange polynomial inter- and extrapolation. The y-locations of the grid points in the vertical direction can be downloaded from this text file. 

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2. Boundary Layer of Transport Equation with In-Flow Boundary

   https://doi.org/10.1007/s00205-019-01461-x  

   Wu, Lei (March 2020, Archive for Rational Mechanics and Analysis)
3. Boundary-Layer Flow Over Complex Topography

   https://doi.org/10.1007/s10546-020-00564-3  

   Finnigan, John; Ayotte, Keith; Harman, Ian; Katul, Gabriel; Oldroyd, Holly; Patton, Edward; Poggi, Davide; Ross, Andrew; Taylor, Peter (December 2020, Boundary-Layer Meteorology)

   null (Ed.)
4. A Conservation-Based Transitional Boundary Layer Model

   https://doi.org/10.1115/1.4054838  

   Brewster, M. Q. (October 2022, Journal of Heat Transfer)

   Abstract A simple, flow-physics-based model of flat-plate, transitional boundary layer skin friction and heat transfer is presented. The model is based on the assumption of negligible time-, spanwise-, and streamwise-average wall-normal velocity at the top of the boundary layer. This results in a threefold increase in boundary layer thickness over the transition region. This simple velocity assumption and its boundary-layer growth implications seem to be reasonably consistent with more sophisticated (direct numerical simulation (DNS)) modeling simulations. Only two modeling parameters need to be assumed, the Reynolds numbers at the onset and at the completion of transition, for which there is guidance based on freestream turbulence intensity for smooth plates. Several experimental datasets for air are modeled. New criteria are proposed to help define the onset and completion of transition: zero net vertical (wall-normal) velocity or mass flux (integrated in time and space, spanwise and streamwise) at the top of the boundary layer, and tripling of boundary layer thickness. Also presented is a minor improvement to a previously published unheated starting length factor for flat-plate laminar boundary layers with uniform wall heat flux. 

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5. Surprises in a Classic Boundary-Layer Problem

   https://doi.org/10.1137/21M1436087  

   Clark, William A.; Gomes, Mario W.; Rodriguez-Gonzalez, Arnaldo; Stein, Leo C.; Strogatz, Steven H. (February 2023, SIAM Review)