Study on thermoacoustic oscillation characteristics of carbon nanotubes

In order to study the nonlinear dynamic combustion response characteristic of solid propellant under the limit amplitude of oscillation, a stable and controllable acoustic source is needed to produce large amplitude of pressure oscillation in the combustor. Based on the principle of thermoacoustics, this paper studies a method of producing large amplitude of pressure oscillations in a tube combustor using carbon nanotubes. Using the low-order thermoacoustic network model, the thermoacoustic oscillation characteristics of a tubular combustor closed at both ends at different heat source positions (0.125 m/0.2 m/0.25 m/0.3 m/0.4 m), heat release power (239 W ~ 765 W), and mean pressure (10.1325 kPa ~ 300 kPa) were studied. Results show that different heat source positions and heat release power have a great impact on the amplitude of pressure oscillations; Under the conditions of heat source position x=0.125 m, maximum heat release power (765 W), and mean pressure of 100 kPa, the maximum pressure oscillation amplitude can reach 20.67% of the mean pressure; as the mean pressure decreases, the ratio of the amplitude of the pressure oscillation to the mean pressure gradually increases. The research results show that under certain conditions, based on the thermoacoustic characteristics of carbon nanotubes, a certain amplitude of pressure oscillations can be produced in the closed tubular combustor. In the future, relevant experimental research on thermoacoustic oscillations using carbon nanotubes will be carried out in laboratory combustors.