<p>Rotors play a major role in various applications including ventilation and propulsion systems such as in helicopters, drones, gas turbines and wind turbines. This visualization of instantaneous vortical structures (identified by the <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\lambda _2\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>λ</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> criterion) shows complex flow structures emanating from a twisted drone rotor that is impulsively starting to rotate at 1600 rpm. Initially, a starting vortex is formed as a result of lift generation and shed as a connected vortex tube from the entire surface of the blade, which has a strong connection to the blade tip via the so-called tip vortex. Leading edge separation occurs at span positions of high twist, followed by wave-induced breakdown to turbulence along the whole wing span. This turbulence then sheds as small-scale vortices into the wake and dissipates. Understanding the behaviour of these vortices from such complex blades and how they interact with the other blade is critical to design more efficient and potentially more silent propellers.</p> Graphical abstract <p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Direct numerical simulation of a starting rotor at \(Re_c=15000\)

  • Ronith Stanly,
  • Eman Bagheri,
  • Adam Peplinski,
  • Siavash Toosi,
  • Niclas Jansson,
  • Timofey Mukha,
  • Philipp Schlatter

摘要

Rotors play a major role in various applications including ventilation and propulsion systems such as in helicopters, drones, gas turbines and wind turbines. This visualization of instantaneous vortical structures (identified by the \(\lambda _2\) λ 2 criterion) shows complex flow structures emanating from a twisted drone rotor that is impulsively starting to rotate at 1600 rpm. Initially, a starting vortex is formed as a result of lift generation and shed as a connected vortex tube from the entire surface of the blade, which has a strong connection to the blade tip via the so-called tip vortex. Leading edge separation occurs at span positions of high twist, followed by wave-induced breakdown to turbulence along the whole wing span. This turbulence then sheds as small-scale vortices into the wake and dissipates. Understanding the behaviour of these vortices from such complex blades and how they interact with the other blade is critical to design more efficient and potentially more silent propellers.

Graphical abstract