Study of impact of viscous-terms approximation on accuracy of numerical solution of gas dynamics equations

The paper studies an influence of viscous?terms approximation on the accuracy of numerical solution of gas dynamics equations under condition of high accuracy (upto the 6th order) approximation of convective terms and the second order accuracy of approximation of viscous ones. A comparative analysis of three mathematical models, the Navier–Stokes equations, linearized Navier–Stokes equations and nonlinear disturbance equations, depending on the solution amplitude and the Reynolds number is performed. The paper also investigates an impact of viscous-terms approximation on stability of all the numerical models under consideration to round off errors.