Experimental investigation of Vortex Generator and Gurney Flap performance effect under dynamic stall and rotational effects

涡流发生器(VG)和Gurney襟翼(GF)等坚固、高效且易于实施的被动流量控制设备尤其适用于追求更高性能和寿命的风力涡轮机应用。然而，风力涡轮机的一个特殊性是它们在湍流条件下运行，因此会经历动态失速。这使得在静态条件下进行的所有被动流量控制装置的研究在其适用性方面相当有限。此外，风力机叶片上的旋转效应起着至关重要的作用，任何完整的研究都不应将其排除在外。尽管已经在直升机旋翼机架上进行了一些相关研究，但风力涡轮机面临着特殊的挑战(例如，不同的湍流时间尺度、增加的叶片厚度、不断分离的径向流动)，这就需要对风力涡轮机模型进行专门的测试。此外，在动态失速或旋转叶片机架中，VG和GF组合应用的研究还很少，而且几乎不存在。拟议的项目旨在超越目前的技术水平，弥补上述知识差距。这将通过对装有VGS和GFS的俯仰翼型和安装了被动流动控制装置的三米小型水平轴风力机模型(BERT)进行扩展风洞研究来实现。该研究与目前的全尺寸小型风力机直接相关，是将VGS和GFS结合应用于大型风力机的第一步。本研究的目的是：1.探索一种有效的VG布局，用于经历动态失速的风力机翼型。为经历动态失速的风力机翼型找出最优的GF构型。找出了风力机翼型动态失速时VGS和GFS正效应相结合的最佳方法。研究了风洞中实际风力机模型BERT上所选VG、GF和VG+GF构型的绕流情况。建立一个广泛和准确的实验数据库，用于验证未来VGS和GFS效应的数值模型。

Robust, effective and easily implemented passive flow control devices such as vortex generators (VG) and Gurney Flaps (GF) are particularly appealing for wind turbine applications where increased performance and longevity is sought after. However, one of the particularities of wind turbines is that they operate in turbulent conditions and as a result experience dynamic stall. This renders all passive flow control device studies performed under static conditions rather limited with regard to their applicability. Furthermore, rotational effects on wind turbine blades play a crucial role and no complete investigation should exclude them. Although some relevant research has been conducted in a helicopter rotor frame, wind turbines face specific challenges (e.g., different turbulence time scales, increased blade thickness, constantly separated radial flow) that call for dedicated tests on wind turbine models. Additionally, research in combined VG and GF application is scarce and practically non-existent in a dynamic stall or rotating blade frame. The proposed project aims at progressing beyond the current state of the art and by covering the aforementioned knowledge gaps. This will be achieved by performing an extended wind tunnel study on pitching airfoils equipped with VGs and GFs and on a three meter small horizontal axis wind turbine model (BeRT) also equipped with passive flow control devices.The investigation is directly relevant to current full-scale small wind turbines and is the first step towards the combined application of VGs and GFs to large wind turbines.The objectives of the proposed investigation are to:1. Explore an effective VG configuration for a wind turbine airfoil experiencing dynamic stall.2. Find an optimal GF configuration for a wind turbine airfoil experiencing dynamic stall.3. Find the best way to combine the positive effects of VGs and GFs for a wind turbine airfoil experiencing dynamic stall.4. Study the flow past the selected VG, GF and VG + GF configurations on the actual wind turbine model BeRT in a wind tunnel.5. Generate a broad and accurate experimental data base that will be used to validate numerical models of the effect of VGs and GFs in the future.