Shock-wave modes of flow at the inlet to the diffuser of a hypersonic scramjet engine: the effect of flight altitude and velocity

Abstract

This paper is devoted to development of acoustic methods for the investigation of the dynamics of structural changes in iron-based alloys, which are associated with phase transitions, processes of recrystallization and relaxation, and physical stimulation of various types. Samples of Armco iron are used to obtain the temperature dependences of the velocity and attenuation of ultrasound in the range from 20 to 1040 °C. The acoustic properties of 08Kh14AN4MDB high-strength corrosion-resistant martensitic steel are measured in the same temperature range. The obtained data on the propagation velocity of sound are used to calculate the values of the elastic modulus of Armco iron and 08Kh14AN4MDB steel in the range from 20 to 950 °C.