本文提出了一种集成化构型的双膜三腔合成射流激励器(Dual-Diaphragm Three-Cavity Synthetic Jet Actuator, D2C3A)，采用 PIV 流场测量技术从旋涡演化和能量转递的角度系统研究了其自由发展特性。根据流场演化规律，将全域划分为四个特征区域：Ⅰ形成区(y<0.71 mm)、Ⅱ发展区(y=0.71-4.24 mm)、Ⅲ融合区(y=4.24-17.29 mm)和Ⅳ衰减区(y>17.29 mm)，详细阐述了各区域内速度场、涡量场、动能、射流宽度、质量流率和动量通量的演化规律和相互影响机制。研究结果表明在Ⅲ融合区，y≈4.24 mm处发生了旋涡融合和“轴交换”，使得卷吸和掺混能力增强，展向时均速度由三峰值过渡为典型的单峰高斯分布，流向时均速度呈现出显著的自相似特征，在流场稳定区范围为x=-4.21-4.26 mm，y=7.06-17.29 mm。此外，流向时均速度与动量通量的变化趋势高度吻合，均呈现双峰分布且峰值位置完全重合，印证了动量传递与速度场演化的强耦合关系。本文为高效、定点、远场流动控制，掺混增强和热管理等领域提供了新思路。

A novel integrated dual-diaphragm three-cavity synthetic jet actuator (D2C3A) is proposed in this study. Particle Image Velocimetry (PIV) flow field measurement technology is employed to systematically investigate its free development characteristics from the perspectives of vortex evolution and energy transfer. Based on the flow field evolution laws, the entire flow domain is divided into four characteristic regions: Ⅰ Formation region (y < 0.71 mm), Ⅱ Development region (y = 0.71–4.24 mm), Ⅲ Merging region (y = 4.24–17.29 mm), and Ⅳ Decay region (y > 17.29 mm). The evolution laws and interdependent mechanisms of the velocity field, vorticity field, kinetic energy, jet width, mass flow rate, and momentum flux in each region are elaborated in detail. The results demonstrate that vortex merging and "axis switching" occur at y ≈ 4.24 mm in the Ⅲ Merging region, which significantly enhances the entrainment and mixing capabilities. Consequently, the spanwise time-averaged velocity transitions from a triple-peak distribution to a typical single-peak Gaussian distribution, while the streamwise time-averaged velocity exhibits distinct self-similar characteristics and forms a stable flow field region in the downstream (y = 7.06–17.29 mm). Notably, the streamwise time-averaged velocity and momentum flux show highly consistent variation trends, both presenting a double-peak distribution with completely coincident peak positions, which verifies the strong coupling relationship between momentum transfer and velocity field evolution. This study provides new insights for applications in high-efficiency, targeted, long-range flow control, mixing enhancement, and thermal management.