外笼套式节流阀气动噪声特性分析及优化

Analysis and Optimization of Aerodynamic Noise Characteristics ofCorbula-Type Throttle Valve

为解决外笼套式节流阀在生产过程中产生的高噪声问题,采用大涡模拟对外笼套式节流阀流场进行模拟计算。从流场特征角度分析气动噪声产生的机制,并基于此提出结构改进方法。通过Box-Behnken响应面设计,以改进结构的孔径、孔数和孔长为优化变量,以监测点总声压级为优化目标,开展降噪结构优化设计。结果表明:节流孔结构突变使流体介质在阀门下游形成多尺度多样化复杂流动,结构改进后流场内压力和速度脉动减小,湍化程度降低,具有二次节流和降噪效果;孔径的变化对监测点总声压级响应值的影响最为明显;对应流道模型的数值模拟结果与系统预测响应值之间的误差为1.19%,验证了BBD响应面法优化结果的可靠性;优化后节流阀总声压级下降了13.1 dB,达到了预期的降噪目的。

In order to solve the problem of high noise generated by the outer cage throttling valve in the production process,the flow field of the outer cage throttle valve was simulated and calculated by large eddy simulation.The mechanism of generating aerodynamic noise was analyzed based on the flow field characteristics,and structural improvement method was proposed.Through Box-Behnken response surface design,the hole diameter,number and length of the improved structure were taken as optimization variables.Taking the total sound pressure level of the monitoring point as the optimization objective,the optimization design of noise reduction structure was carried out.The results show that the fluid medium forms multi-scale diversified and complex flow downstream of the valve due to the abrupt orifice structure,and the pressure and velocity pulsation in the flow field are decreased and the turbulence degree is reduced after the structure improvement,which has the effect of secondary throttling and noise reduction.The change of hole diameter has the most obvious influence on the total sound pressure level response value of the monitoring point.The error between the numerical simulation results of the corresponding flow channel model and the predicted response value of the system is 1.19%,which verifies the reliability of the optimization results of BBD response surface method.After optimization,the total sound pressure level of the throttle valve is reduced by 13.1 dB,and the expected noise reduction is achieved.