Purpose

Flow separation on wings, blades and vehicles can be delayed or even suppressed by the use of vortex generators (VG). Numerous studies, documented in the literature, extensively describe the performance of triangular and rectangular VG winglets. This paper aims to focus on the use of non-conventional VG shapes, more specifically an array of trapezoildal-perforated VG tabs.

Design/methodology/approach

In this study, computational fluid dynamic simulations are performed on an inline array of trapezoidal VG with various dimensions and inclination angles, in addition to considering perforations in the VG centers. The methodology of the present numerical study is validated with experimental data from the literature.

Findings

The performance and the associated flow structures of these tested non-conventional VG are compared to classical triangular winglets. For the proposed non-conventional trapezoidal VG, at the onset of stall, a 21% increase of lift over drag on the airfoil is observed. The trapezoidal VG enhancement is also witnessed during stall where the lift over drag ratio is increased by 120% for the airfoil and by 10% with respect to the triangular winglets documented in the literature.

Originality/value

The originality of this paper is the use of non-conventional vortex generator shape to enhance lift over drag coefficient using three-dimensional numerical simulations.

中文翻译：

---

使用梯形涡流发生器增强机翼的空气动力学性能

目的

使用涡流发生器（VG）可以延迟甚至抑制机翼，叶片和车辆上的气流分离。文献中记录的大量研究广泛描述了三角形和矩形VG小翼的性能。本文旨在集中于非常规VG形状的使用，更具体地说是一系列梯形穿孔的VG凸耳。

设计/方法/方法

在这项研究中，除了考虑在VG中心打孔以外，还对具有各种尺寸和倾斜角度的梯形VG的直列阵列执行计算流体动力学模拟。本数值研究的方法论已得到来自文献的实验数据的验证。

发现

将这些经过测试的非常规VG的性能和相关的流动结构与经典三角小翼进行了比较。对于建议的非常规梯形VG，在失速开始时，观察到翼型上的升力比阻力增加了21％。失速期间还可以看到梯形VG的增强，其中翼型的升力阻力比增加了120％，相对于文献中记载的三角形小翼，则增加了10％。

创意/价值

本文的独创性是使用非常规涡流发生器形状通过三维数值模拟来增强升力阻力系数。