@inproceedings {Simula.sc.1126,
	title = {Post-Processing of Marginally Resolved Spectral Element Data},
	journal = {Spectral and High Order Methods for Partial Differential Equations},
	volume = {76},
	year = {2011},
	note = {Is listed in the 2009 Annual Report},
	pages = {503-510},
	publisher = {Springer Berlin Heidelberg},
	type = {Conference},
	abstract = {When derivatives of a spectral element solution are used in a different context, such as visualization or in calculations with a different numerical method, the discontinuity of the derivatives at the element interfaces is a potential problem. Asymptotically, the jumps in the derivatives decay spectrally fast, but it is not always possible or efficient use of computational resources to repeat the spectral element calculations with increased resolution. The usual way of treating the discontinuities is discussed here, however it is not always satisfactory. New methods based on polynomial interpolation across element interfaces and polynomial filtering are suggested, and illustrated by examples.},
	isbn = {978-3-642-15337-2},
	doi = {10.1007/978-3-642-15337-2\_49},
	author = {Carl Erik {Wasberg}},
	editor = {Jan S. {Hesthaven} and Einar M. {R{\o}nquist}}
}
@article {Simula.sc.976,
	title = {Assessment of the Finite Volume Method Applied to the V{^2} {-} F Model},
	journal = {International Journal for Numerical Methods in Fluids},
	volume = {63},
	number = {4},
	year = {2010},
	note = {Appeared online 2009.},
	month = {June},
	pages = {495-516},
	abstract = {The objective of this paper is to assess the accuracy of low-order finite volume (FV) methods applied to the v2 {-} f turbulence model of Durbin (Theoret. Comput. Fluid Dyn. 1991; 3:1-13) in the near vicinity of solid walls. We are not (like many others) concerned with the stability of solvers - the topic at hand is simply whether the mathematical properties of the v2 {-} f model can be captured by the given, widespread, numerical method. The v2 {-} f model is integrated all the way up to solid walls, where steep gradients in turbulence parameters are observed. The full resolution of wall gradients imposes quite high demands on the numerical schemes and it is not evident that common (second order) FV codes can fully cope with such demands. The v2 {-} f model is studied in a statistically one-dimensional, fully developed channel flow where we compare FV schemes with a highly accurate spectral element reference implementation. For the FV method a higher-order face interpolation scheme, using Lagrange interpolation polynomials up to arbitrary order, is described. It is concluded that a regular second-order FV scheme cannot give an accurate representation of all model parameters, independent of mesh density. To match the spectral element solution an extended source treatment (we use three-point Gauss-Lobatto quadrature), as well as a higher-order discretization of diffusion is required. Furthermore, it is found that the location of the first internal node need to be well within y+=1},
	doi = {10.1002/fld.2091},
	author = {Mortensen, Mikael and Bj{\o}rn Anders Petterson {Reif} and Carl Erik {Wasberg}}
}
@article {Simula.sc.994,
	title = {Variational Multiscale Turbulence Modelling in a High Order Spectral Element Method},
	journal = {Journal of Computational Physics},
	volume = {228},
	number = {19},
	year = {2009},
	month = {October},
	pages = {7333-7356},
	abstract = {In the variational multiscale (VMS) approach to large eddy simulation (LES), the governing equations are projected onto an a priori scale partitioning of the solution space. This gives an alternative framework for designing and analyzing turbulence models. We describe the implementation of the VMS LES methodology in a high order spectral element method with a nodal basis, and discuss the properties of the proposed scale partitioning. The spectral element code is first validated by doing a direct numerical simulation of fully developed plane channel flow. The performance of the turbulence model is then assessed by several coarse grid simulations of channel flow at different Reynolds numbers.},
	doi = {10.1016/j.jcp.2009.06.029},
	author = {Carl Erik {Wasberg} and Gjesdal, Thor and Bj{\o}rn Anders Petterson {Reif} and Andreassen, {\O}yvind}
}
