Home – Home – Jornals – Thermophysics and Aeromechanics 2002 number 2

The probes for pressure measurement are usually mounted at the butt end of a narrow duct adhering to the tested volume. A question of the agreement between the pressure measured in this way and the true pressure in the volume is considered. The problem is solved for short ducts within the framework of the Euler equations. The disturbance is created in the tested volume by an instant local release of energy. The MacCormack method is used for the solution together with a grid procedure, which enables us to introduce in some subregions a grid with the cell sizes less by an order. This technique does not produce oscillations and nonphysical waves. A considerable excess of the mean pressure near the narrow duct bottom over the mean pressure in the volume has been revealed, which is related to the effect of anomalous aerodynamic heating. The dispersion of gas density and temperature in the tested volume is very significant during a long time. The research results cast doubt on the possibility of using only one pressure measured with the aid of a probe in a narrow duct to determine the flow parameters in hot-shot wind tunnels and in the ducts of aggregates with rapid processes.