合成射流致动器的设计研究

【作者】 郝礼书；

【导师】 乔志德；

【作者基本信息】 西北工业大学 ， 流体力学， 2005， 硕士

【摘要】 合成射流技术是国外最近发展起来的一种新概念的流动控制技术。该技术的核心是合成射流致动器,它具有不需要气源和外界质量注入、结构简单、容易实现批量生产和集成等优点。致动器的设计研究直接关系到合成射流技术的进一步发展以及在分离控制、边界层控制、增强混合等方面的应用前景。 本文采用了实验和计算相结合的方法,研究了合成射流致动器设计和出口流动特性,进行了翼型流动控制的实验。主要工作体现在以下几个方面:(1)对二维合成射流的外部流场进行了数值模拟研究;(2)设计了合成射流致动器和其控制电路;(3)对合成射流致动器的外部流场进行了速度测量;(4)进行了合成射流用于YLSG107翼型流动控制的实验尝试。 采用二维非定常不可压N-S方程对合成射流的外部流动进行了数值模拟。结果再现了涡对的生成、迁移和扩散过程以及射流对周围流体存在的卷吸作用。计算了以不同出口速度边界条件及驱动频率的情形,得到了重要的外部流场信息。 实验中设计的电磁式致动器,采用传统的精密技术进行加工,并且通过自行制作的功率放大电路提高了致动器的驱动能量。利用TSI-IFA300热线风速仪系统对致动器喷口外的流场进行了测量。实验研究了在三角波、正弦波和方波三种驱动波形和不同驱动频率下射流场的横向速度和中心线速度分布。结果表明方波产生的合成射流最强,三角波产生的最弱。在喷口不远处,充分发展的二维射流已经形成。该致动器存在两个共振频率,在共振频率下工作,方波分别出现了4.70m/s和4.22m/s的峰值。最后对合成射流用于翼型流动控制进行了实验尝试。实验结果表明本文设计的合成射流致动器对翼型的失速特性有一定的改善,并就存在的问题进行了探讨性的分析和总结。更多还原

【Abstract】 Synthetic jet is well known as a novel method of active flow control. The core of technique is synthetic jet actuator. It is of three advantages such as: no gas source and mass injecting, simple structure, and compatible for integrated fabrication. The further progress of synthetic jet is dependent on the design of actuators which have influence on promising applications such as: separation control, boundary control and mixing strengthening.The design of synthetic jet actuator and characteristic of flow field are studied by the method combined experiment and numerical simulation, and flow control on airfoil is investigated experimentally. The work of paper includes mainly four parts as follow: (1) The flow field of 2-D synthetic jet is simulated; (2) The synthetic jet actuator and control circuit are designed; (3) The velocity of the synthetic jet flow field is measured; (4) The control of flow on YLSG107 airfoil using synthetic jet actuator is investigated experimentally.By adopting the 2-D unsteady ,incompressible Reynolds Averaged Navier-Stokes (RANS) equations, the flow field of synthetic jet is simulated. The results clearly reveal the features of synthetic jet and the process of vortex pairs’ formation, advection ,diffusion and entrainment effect on ambient fluid. The effects of boundary condition at the orifice and actuation frequency on jet flow field are numerical investigated. The information of the flow field is obtained.The designed actuator is driven by electromagnet force. Which is machined by precise instrument. The designed power amplifier circuit is used to increase the energy of actuator. The measurement of velocity of the jet flow field is carried out with the TSI-IFA300 constant temperature anemometer. The velocity profile and the center line velocity of jet flow field in three different actuation signals(triangular wave, sinusoidal wave and square wave) and different actuation frequencies are studied experimentally. It is shown that the square wave has the best actuation result and the triangular wave has the worst one. A full developed, two-dimensional jet is formed by the slot. The two resonance frequencies are 475Hz and 1700Hz .When the actuator is actuated with a square wave, the corresponding mean velocities are 4.70m/s and 4.22m/s. At last, the experiment using synthetic jet to fulfill the airfoil flow control is performed. The results show that stalling characteristic is improved,and problems in experiment are discussed.更多还原