skip to main content
Idioma:

Discrete-vortex method with novel shedding criterion for unsteady aerofoil flows with intermittent leading-edge vortex shedding

Ramesh, Kiran ; Gopalarathnam, Ashok ; Granlund, Kenneth ; Ol, Michael V. ; Edwards, Jack R.

Journal of fluid mechanics, 2014-07, Vol.751, p.500-538 [Periódico revisado por pares]

Cambridge, UK: Cambridge University Press

Texto completo disponível

Citações Citado por
  • Título:
    Discrete-vortex method with novel shedding criterion for unsteady aerofoil flows with intermittent leading-edge vortex shedding
  • Autor: Ramesh, Kiran ; Gopalarathnam, Ashok ; Granlund, Kenneth ; Ol, Michael V. ; Edwards, Jack R.
  • Assuntos: Aerodynamics ; Applied fluid mechanics ; Exact sciences and technology ; Fluid dynamics ; Fluid mechanics ; Fundamental areas of phenomenology (including applications) ; Kinematics ; Physics ; Reynolds number ; Rotational flow and vorticity ; Separated flows ; Vortices
  • É parte de: Journal of fluid mechanics, 2014-07, Vol.751, p.500-538
  • Descrição: Unsteady aerofoil flows are often characterized by leading-edge vortex (LEV) shedding. While experiments and high-order computations have contributed to our understanding of these flows, fast low-order methods are needed for engineering tasks. Classical unsteady aerofoil theories are limited to small amplitudes and attached leading-edge flows. Discrete-vortex methods that model vortex shedding from leading edges assume continuous shedding, valid only for sharp leading edges, or shedding governed by ad-hoc criteria such as a critical angle of attack, valid only for a restricted set of kinematics. We present a criterion for intermittent vortex shedding from rounded leading edges that is governed by a maximum allowable leading-edge suction. We show that, when using unsteady thin aerofoil theory, this leading-edge suction parameter (LESP) is related to the $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}A_0$ term in the Fourier series representing the chordwise variation of bound vorticity. Furthermore, for any aerofoil and Reynolds number, there is a critical value of the LESP, which is independent of the motion kinematics. When the instantaneous LESP value exceeds the critical value, vortex shedding occurs at the leading edge. We have augmented a discrete-time, arbitrary-motion, unsteady thin aerofoil theory with discrete-vortex shedding from the leading edge governed by the instantaneous LESP. Thus, the use of a single empirical parameter, the critical-LESP value, allows us to determine the onset, growth, and termination of LEVs. We show, by comparison with experimental and computational results for several aerofoils, motions and Reynolds numbers, that this computationally inexpensive method is successful in predicting the complex flows and forces resulting from intermittent LEV shedding, thus validating the LESP concept.
  • Editor: Cambridge, UK: Cambridge University Press
  • Idioma: Inglês
Links
Voltar para lista de resultados
Ir para página anteriorAnterior Resultado  10 AvançarIr para próxima página

  • Realização: ABCD-USP USP   Logos de Redes Sociais: Freepik

Buscando em bases de dados remotas. Favor aguardar.