Experimental and numerical study on attenuation of shock waves in ventilation pipes

With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements. The attenuation mechanism and the propagation law of shock waves in ventilation pipes of different structures are investigated by experiments and numerical simulations. Furthermore, for the same structure, the effects of peak pressure and positive pressure time on the attenuation rate are discussed. It is found that the attenuation rate increases with the incident shock wave pressure, and the shock wave attenuation rate tends to reach its limiting value k for the same structure and reasonably short positive pressure time. Under the same conditions, the attenuation rate is calculated using the pressure of the shock wave as follows: diffusion chamber pipe, branch pipe and self-consumption pipe; the attenuation rate per unit volume is calculated as follows: self-consumption pipe, branch pipe and diffusion chamber pipe. In addition, an easy method is provided to calculate the attenuation rate of the shock wave in single and multi-stage ventilation pipes. Corresponding parameters are provided for various structures, and the margin of error between the formulae and experimental results is within 10%, which is significant for engineering applications.