Synthetic Jet Flowfield Database for Computational Fluid Dynamics Validation

Abstract

A workshop on computational fluid dynamics (CFD) validation of synthetic jets and turbulent separation control was held at the NASA Langley Research Center in 2004 to assess the current CFD capability to predict an unsteady flowfield. Three selected test cases were 1) a basic flowfield generated by a synthetic jet in a quiescent environment, 2) a round oscillatory jet in a crossflow, and 3) the control of separated flow over a wall-mounted hump model. This paper describes the flowfield database for case 1. Flowfield measurements were obtained using three different techniques: particle image velocimetry (PIV), laser Doppler velocimetry (LDV), and hot-wire anemometry. In addition, the actuator operating parameters, including diaphragm displacement, internal cavity pressure, and internal cavity temperature, were documented to provide boundary conditions for CFD modeling. Among activeflow control devices being developed, synthetic jets have demonstrated promising flow control applications [1]. Considerable studies have covered the development of the actuator and the general behavior of the synthetic jets. However, there has not been a complete data set to support the validation of CFD prediction of synthetic jets. Smith and Glezer [2] measured the velocity profile of plane jets from rectangular slots with hot-wire and flow visualization. Crook et al. [3] studied the development of a round jet using an analytical model and compared their results with hot-wire measurements. Mallinson et al. [4] studied a round jet with variable orifice diameters and cavity heights using a hot wire. Chen et al. [5] provided velocity profiles at the centerline of a plane jet, and jet exit velocity profiles with a hot wire. Muller et al. [6] used PIV to measure the detailed flowfield of a circular jet. Bera et al. [7] used PIV to map plane synthetic jet flows from a 2-D slot. Guy et al. [8] studied a plane synthetic jet with hot-wire measurements. This study was not intended to be a parametric survey or performance optimization of synthetic jets. Experiment Setup