## 1 Introduction  
The use of Computational Fluid Dynamics (CFD) is becoming widespread in all branches of engineering due to advances in the development of numerical methods and the increase in achievable computational power. One of the main difficulties to be addressed is the generation of an adequate mesh for the simulated domain, since most numerical errors depend on the mesh quality (see [1]). Due to this reason, one of the most important parts of CFD modeling works found in the literature is the mesh independence analysis [2; 3; 4]. There are efforts specially devoted to meshing strategies in complex flow simulations [5; 6]. [PERSON] et al. [7] presented an innovative mesh independence analysis that allows to optimize the mesh distribution. The analysis was successfully applied to unstructured meshes in several works [8; 9]. The review by [PERSON] [10] shows that origin of anisotropy in fluid flows might come from different sources. Several works on the literature deal with flow anisotropy in relativistic flows [11; 12] or microfluidic devices [13]. The present work is focused on the anisotropy existing in conducting fluidsunder the effect of a magnetic field. The study of the motion of conducting fluids has been performed by several authors [14]. The current manuscript is focused in the numerical analysis of the flow behavior of magnetized conducting fluids, such as the plasmas found in electric propulsion devices and, more in particular, related to the electron flow, which is generally the only \"magnetized\" species, i.e. the plasma is mesomagnetized. Furthermore, since electrons are generally well confined by electric and magnetic fields, a typical assumption in the modeling of the electron population is to consider a quasi-maxwellian fluid of a highly anisotropic nature, in which transport in the perpendicular and parallel directions to the magnetic field is widely different (see [15]). The classical plasma transport theory states that the perpendicular electron transport coefficient is inversely proportional to the square of the magnetic field strength, \(B^{-2}\) and is always smaller, up to various orders of magnitude, than the parallel transport coefficient [15]. This anisotropicity of the transport coefficients may induce a numerical error when numerically solving the flow transport equations, the error becoming more significant if the computational mesh is unaligned with the principal magnetic directions. This numerical error is commonly known as numerical diffusion. [PERSON] et al. [16] analyzed this problem by solving the heat conduction equation with the high-order spectral element code SEL/HiFi [17]. The study concluded that even small grid misalignments cause significant numerical error. The error could be reduced by refining the mesh or by increasing the order of the dicretization elements. A similar study was conducted by [PERSON] [18] demonstrating that a numerical diffusion arises when solving the Magneto-Hydro-Dynamic (MHD) equations in an axisymmetric 2D Cartesian grid with the magnetic field misaligned with respect to the grid directions. The work showed that even in the limit of anisotropy ratio tending to \(\infty\) (zero perpendicular transport), the flow field showed non-zero perpendicular transport. As shown in the previously described works, numerical diffusion can be reduced by refining the mesh or increasing the order of the numerical method [16; 18]. Another possible mechanism to decrease the influence of this artificial numerical diffusion on the solution is the use of a mesh that is aligned with the the preferential directions of the problem; in the case of conducting fluids, those defined by the magnetic field. Indeed, in the particular case of the electron transport, because of the large anisotropicity in coefficients for the parallel and perpendicular directions, solving the governing equations in a mesh which is misaligned with respect to the magnetic field may lead to cross-contamination of the transport coefficients and thus to numerical diffusion.