PROCESS MODELING

**ANALYSIS OF GAS-DYNAMIC PROCESSES AND DEVELOPMENT**

**OF MODEL OF FLOWS IN HYPERSONIC SHOCK TUBE**

**V.V. Kuzenov**

,

**M.A. Kotov**

Ishlinskii Institute for Problems in Mechanics of the RAS,

Moscow, Russian Federation

e-mail:

kuzenov@ipmnet.ru; mikhail_kotov88@mail.ru
*The paper considers the simplified one-dimensional mathematical models of*

*the processes, which describe both formation and propagation of shock waves,*

*rarefaction waves, and contact discontinuities in shock tubes. These models are based*

*on the quasi-one-dimensional equations of radiation gas dynamics. Experimental and*

*theoretical studies of both the formation and propagation of shock waves, rarefaction*

*waves and contact discontinuities using shock tubes have always been of significant*

*interest and they are currently being developed. It results from the fact that the shock*

*tubes are the most convenient tool of laboratory research in such contemporary fields*

*of modern science and technology as aerophysics and chemical kinetics, gas dynamics*

*and molecular physics. The flows of a multicomponent gas proves to be important*

*for many modern technological and power facilities as well as in hypersonic aircraft.*

*The multicomponent gas undergoes chemical conversions, oscillatory, and electron*

*excitation. A relatively simple instrument for creating non-equilibrium processes in*

*the gases is a shock wave propagating in a tube of a circular or rectangular cross-*

*section. This cross-section geometry allows simplifying the gas-dynamic flow pattern*

*in the working section.*

*Keywords*

:

shock tube, gas dynamics equations, nonlinear quasimonotonous compact

difference scheme, Runge–Kutta multistep method

**The problem statement.**

The aim of the paper is to examine the

processes of formation and propagation of shock waves (SW), rarefaction

waves and contact discontinuities in shock tubes using simplified one-

dimensional mathematical models.

One of the important tasks is to develop numerical methods and a

computational model code to describe unsteady one-dimensional radiation-

magnetogasodynamic processes in different types of shock tubes.

**Description of processes occurring in shock tubes.**

The shock tubes

that generate shock waves have the following principle of operation (Fig. 1):

the shock wave is generated in the tube containing a test (driven) gas when

a “piston” of some kind is moving at a hypersonic speed. The shock tube, in

which a compressed air is used for generating shock waves, operates in the

most effective way when the ratio of the velocity of a sound in the working

gas (

C

R

— driver gas) to the velocity of sound in the test gas (

C

St

— driven

gas) is sufficiently high (

C

R

/C

St

1)

. The heating of the driver gas in

a shock tube with an electric discharge, solid or gaseous substances may

be accompanied by a remarkable increase of the ratio mentioned above.

This is related to the fact that the gas temperature can increase from 2 кK

(without gas heating) up to 20 кK (with gas heating), which results in the

ISSN 0236-3941. HERALD of the BMSTU. Series “Mechanical Engineering”. 2014. No. 1 3