Numerical Simulation on the Sound Field of Gas Valve Due to Inner Leakage

Recently, acoustic testing method has been widely used for valve leakage inspection. Traditional method has difficulty carrying out research on the acoustic testing of valve leakage due to the complex geometry of the valve and the effect of flow on sound field. Thus, a numerical method was put forward based on Reynolds average N-S equation and k – ε equation in order to investigate the flow of the inner leakage of ball valve, needle valve and gate valve. Furthermore, difference time domain method was adopted to simulate the noise field of the flow based on Lighthill acoustic equation. And the characteristics of acoustic distribution were obtained. The results showed that turbulent flow was the main cause of jet noise inner the valve due to gas leakage. And the acoustic distribution had directivity. There were about 10 ∼ 25dB difference between the upstream and downstream of the leaking valve. The position with the highest sound pressure was also found out.