摘要
基于流体力学、传热学和声学研究成果,采用内外流场耦合建模的方法研究Rijke管脉动内流场,解决了大振幅驻波热声场管口边界条件的处理和出现数值发散的问题。从能量平衡的角度出发,提出非定常的热流量与声压、质点振速之间关系的假设。依靠自身参量,如气体的脉动压力、脉动流速和温度波动,来激发Rijke管振荡.模拟了Rijke管的声学特性,分析了Rijke管自激励振荡的机理。运用该模拟方法对不同尺寸、不同管口形状的Rijke管进行了数值实验,模拟结果与实验结果较好吻合,能捕捉Rijke管的管口声学特征量。
Based on the results of fluid dynamics, heat transfer and acoustics, a Computational Fluid Dynamics （CFD） method was utilized to study the acoustic characteristics and self-excited pulsation mechanism inside a Rijke pipe. To avoid settling the irrational boundary conditions of the finite-amplitude standing wave in Rijke thermoacoustic system, the simulation modeling in the flow field, which coupled the inner of pipe with its outer space was carried out to replace the traditional way in form of internal flow field numerical investigations. A hypothesis for heat source in energy equation including the relationship on unsteady heat of air around heat source, oscillation pressure and oscillation velocity was presented. To reflect the essence of Rijke pipe, simulation on self-excited oscillation was obtained by means of its own pulsation of pressure, velocity and temperature. This method can make the convergence process steady and effectively avoid the divergence. The physical phenomenon of self-excited Rijke pipe was analyzed. Moreover, the mechanisms on Rijke pipe＇s self-excited oscillation were explained. Based on this method, comparative researches on the acoustic characteristic of Rijke pipe with different size and different shape of nozzle were performed. The simulation results agreed with the experimental data satisfactorily. Results showed that this numerical simulation can be used for studying the sound pressure of nozzle for the engineering application of Rijke pipe.
出处
《声学学报》
EI
CSCD
北大核心
2007年第6期559-565,共7页
Acta Acustica
基金
国家自然科学基金(50576087)
浙江省自然科学基金(Z503122)资助项目
关键词
RIJKE管
声学特性
数值研究
内外流场
耦合法
模拟方法
脉动压力
数值实验
Acoustics
Boundary conditions
Computational fluid dynamics
Computer simulation
Heat transfer
Photoacoustic effect
Pulsatile flow
