Purpose

This paper aims to deal with the numerical investigation of laminar separation bubble (LSB) characteristics (length and height of the bubble) of SS007 airfoil at the chord Reynolds number of Re_c = 0.68 × 10⁵ to 10.28 × 10⁵.

Design/methodology/approach

The numerical simulations of the flow around SS007 airfoil were carried out by using the commercial fluid dynamics (CFD) software, ANalysis system (ANSYS) 15. To solve the governing equations of the flow, a cell-centred control volume space discretisation approach is used. Wind tunnel experiments were conducted at the chord-based Reynolds number of Re_c = 1.6 × 10⁵ to validate the aerodynamic characteristics over SS007 airfoil.

Findings

The numerical results revealed that the LSB characteristics of a SS007 airfoil, and the aerodynamic performances are validated with experimental results. The lift and drag coefficients for both numerical and experimental results show very good correlation at Reynolds number 1.6 × 10⁵. The lift coefficient linearly increases with the increasing angle of attack (AOA) is relatively small. The corresponding drag coefficient was found to be very small. After the formation of LSB which leads to burst to cause airfoil stall, the lift coefficient decreases and increases the drag coefficient.

Practical implications

Low Reynolds number and LSB characteristics concept in aerodynamics is predominant for both civilian and military applications. These include high altitude devices, wind turbines, human powered vehicles, remotely piloted vehicles, sailplanes, unmanned aerial vehicle and micro aerial vehicle. In this paper, the micro aerial vehicle flight conditions considered and investigated the LSB characteristics for different Reynolds number. To have better aerodynamic performances, it is strongly recommended to micro aerial vehicle (MAV) design engineers that the MAV is to fly at 12 m/s (cruise speed).

Social implications

MAVs and unmanned aerial vehicles seem to give some of the technical challenges of nature conservation monitoring and law enforcement a versatile, reliable and inexpensive solution.

Originality/value

The SS007 airfoil delays the flow separation and improves the aerodynamic efficiency by increasing the lift and decreasing the drag. The maximum increase in aerodynamic efficiency is 12.5% at stall angle of attack compared to the reference airfoil at Re = 2 × 10⁵. The results are encouraging and this airfoil could have better aerodynamic performance for the development of MAV.

中文翻译：

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微型飞行器SS007机翼上层流分离气泡的数值和实验研究

目的

本文旨在处理在弦弦雷诺数Re _c = 0.68×10 ⁵至10.28×10 ⁵时SS007翼型的层流分离气泡（LSB）特性（气泡的长度和高度）的数值研究。

设计/方法/方法

使用商用流体动力学（CFD）软件，Analysis系统（ANSYS）15对SS007翼型周围的流动进行了数值模拟。为解决流动的控制方程，使用了以单元为中心的控制体积空间离散化方法。在基于弦的雷诺数Re _c = 1.6×10 ⁵下进行风洞实验，以验证SS007翼型的空气动力学特性。

发现

数值结果表明，SS007机翼的LSB特性和空气动力学性能已通过实验验证。数值和实验结果的升力和阻力系数在雷诺数1.6×10 ^5时都具有很好的相关性。升力系数随着迎角的增加而线性增加（AOA）相对较小。发现相应的阻力系数非常小。在形成LSB导致爆裂导致机翼失速后，升力系数减小，阻力系数增大。

实际影响

空气动力学中的低雷诺数和LSB特性概念在民用和军事应用中均占主导地位。这些包括高空设备，风力涡轮机，人力车辆，遥控飞机，水上飞机，无人驾驶飞机和微型飞机。在本文中，微型飞行器的飞行条件考虑并研究了不同雷诺数的LSB特性。为了具有更好的空气动力学性能，强烈建议微型飞行器（MAV）设计工程师将MAV以12 m / s（巡航速度）飞行。

社会影响

MAV和无人驾驶飞机似乎给自然保护监测和执法带来了一些技术挑战，这是一种多功能，可靠且廉价的解决方案。

创意/价值

SS007机翼通过增加升力和减小阻力来延迟气流分离并提高空气动力学效率。在Re = 2×10 ^{5的情况下}，与失速迎角相比，空气动力学效率的最大增加为12.5％。结果令人鼓舞，并且这种翼型对于MAV的发展可能具有更好的空气动力学性能。