SMALL-PERTURBATION LAGRANGIAN EQUATIONS IN GAS DYNAMICS WITH RESPECT TO MEDIUM HEAT CONDUCTION OR MAGNETIC PROPERTIES

G. A. Grishina
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki 1986. Вып.3. С. 10-12.

      Lagrangian variables were used to linearize a 3-D solution of equations in gas dynamics (with medium heat conduction or magnetic properties included or removed). The basic flow may be both one- and two-dimensional. Equations for determining small perturbations along the particle path in a basic flow are given in a vectorized form and in generalized Lagrangian variables.

      The program is intended to solve multidimensional problems in gas dynamics using small perturbation method. The problem is linearized based on the main 1-D solution and linear perturbations are represented as angular variable Fourier series. A numerical procedure is implemented for combined calculations of exact solutions and harmonic amplitudes in multi region problems using the "viscosity cross" scheme. The program is written in FORTRAN within the 1-D Complex. The problem formulation and program organization are described. Numerical results are given which are compared to analytical ones.