Eight-channel frequency-response test of the cylindrical-shell-and-ring assembly in the range 1000 to 8000 Hz

In order to increase the efficiency of a rocket jet propulsion, it is necessary to increase the pressure in the combustion chamber. However, the higher the pressure is in the combustion chamber, the more difficult it is to supply fuel in it through the nozzles using a turbopump unit. The rotation speed of a modern turbopump unit, its mass and overall dimensions become prohibitive. Therefore, engine engineers have the proposal to abandon the traditional calm (deflagration) combustion of fuel, and to replace it with with detonation (combustion with explosions). The jet propulsion with continuous detonation combustion of fuel, which loads the support in the frequency range of 1000 ... 10000 Hz, has the promising outlook in rocket and space technology. Such high-frequency loading is accompanied by the so-called Auger effect, when the modulus of elasticity of the material of a thin-walled structure decreases by 10 times. The nature of high-frequency loading of thin-walled structures has not been studied sufficiently. The results of experimental analysis of high-frequency loading of a cylindrical-shell-and-ring assembly in the frequency range 1000...8000 Hz are represented. It is common way to use the hypothesis of the possibility of Fourier separation of variables in order to solve the boundary value problem of high-frequency loading of aircraft elements. The detected frequency shifts were 40 Hz approximately. It is commensurate with the distance (in frequency) between adjacent vibration tones.

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