强声波在电站锅炉中传播特性的研究

Propagation Characteristics of High-intensity Sound in Power Plant Boilers

对位于可听声频率范围的强声波在电站锅炉中的传播特性进行了研究.基于简单波假设理论,对声压级达到160dB的强声波传播过程中畸变和谐波生成的机理进行了分析研究,并计算了不同频率下声波的冲击波形成距离;计算得到炉内黏热流体介质中伯格斯方程的严格解,研究了发生非线性效应与耗散效应下强声波的传播特性;采用数值计算方法求解了弛豫流体介质中强声波传播的非线性波动方程,讨论了弛豫介质中声波的传播特性.结果表明:冲击波形成距离与声波频率成反比,随着声波频率的增大,非线性效应减弱,耗散效应增强.

Propagation characteristics of high-intensity sound with audio frequencies in power plant boilers were studied. Firstly, the mechanism of distortion and harmonic generation occurring in propagation process of high-intensity sound with pressure level of 160 dB was analyzed based on the hypothesis of sim- ple wave theory, while the formation distance of shock waves was calculated for high-intensity sounds of different frequencies. Secondly, the strict solution of burgers equation for viscous fluid in the furnace was calculated, and the propagation characteristics of high-intensity sound were analyzed under the circum- stance of nonlinear effect and dissipation effect. Finally, the propagation characteristics of high-intensity sound in the relaxation medium were discussed after solving relevant nonlinear wave equations by numeri- cal methods. Results show that the formation distance of shock waves is inversely proportional to the sound frequency; the nonlinear effect weakens while the dissipation effect improves with the rise of sound frequency.