The Effects of Grid Accuracy on Flow Simulations: A Numerical Assessment

Abstract

High-quality, accurate grid generation is a critical challenge in the computational simulation of fluid flows around complex geometries. In particular, the accuracy of the grids is an effective factor in order to achieve a successful numerical simulation. In the current study, we present a series of systematic numerical simulations for fluid flows around a NACA 0012 airfoil using different computational grid generation techniques, including the standard second-order, fourth-order compact, and Theodorsen transformation approaches, to assess the effects of grid accuracy on the flow solutions. The flow solvers are based on the second- and fourth-order schemes for spatial discretizations and Beam-Warming linearization method for time advancement. The obtained grids, as well as the metrics and the corresponding numerical flow solution for each grid generation technique, are compared and studied in detail. It is demonstrated that the quality and orthogonality of the grids is improved by using the fourth-order compact scheme. Moreover, the numerical assessment showed that the accuracy and the quality of the grids directly influence the numerical flow solutions. Finally, the higher-order accurate flow solvers are found to be more sensitive to the accuracy of the generated grid.

A new calculation formula to describe the dynamic pressure of water jet peening with elliptical nozzle for high-efficiency treatment

“…The accuracy of the numerical simulation is affected by factors such as grid quality, grid number, and time step size. 39,40 Therefore, the circular nozzle was selected before the formal simulation to explore the influence of different grid numbers and time steps on the simulation results. During the simulation, the water jet axial dynamic pressure, total pressure, and velocity distribution located on the central axis of the nozzle are used as the basis for the analysis of each nozzle jet characteristic.…”

A Block–Interface Approach for High–Order Finite–Difference Simulations of Compressible Flows

“…Compact FDMs offer additional advantages compared to their non-compact counterparts (see Dennis and Hudson, 1989;Li et al 1995;Cui, 2009;Esfahanian et al 2013, Allahyari et al, 2020. Highorder compact finite difference schemes (Hirsh, 1975;Lele, 1992) are thus widely employed in various fields of computational fluid dynamics.…”

Simulations of Aerodynamic Separated Flows Using the Lattice Boltzmann Solver XFlow

“…These two reasons make the solution convergence difficult or even impossible in most cases. Please note that the dependence of the flow accuracy and the quality of the mesh in N-S solvers as been widely explored in the past, e.g., [1,2].…”