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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2016, Vol. 37 ›› Issue (4): 1114-1126.doi: 10.7527/S1000-6893.2015.0278

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Numerical analysis for low Reynolds number airfoil based on γ-Reθt transition model

CHEN Lili, GUO Zheng   

  1. College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, China
  • Received:2015-06-04 Revised:2015-10-14 Online:2016-04-15 Published:2015-10-23
  • Supported by:

    National High-tech Research and Development Program of China

Abstract:

Michel transition criterion and γ-Reθt transition model have been integrated to complete the aerodynamics analysis of low Reynolds number airfoil. In this paper, Michel transition criterion and laminar separation position are used to estimate transition momentum thickness Reynolds number, then critical Reynolds number and transition length that controls the length of the transition region are computed by Langtry and Tomac empirical correlation, respectively. The three empirical correlation values are read into Fluent by User-Defined Functions (UDF) to implement the numerical analysis for E387 airfoil (Reynolds number is 3×105), then the results are compared with experiment. The results demonstrate that Michel-based criterion has more accurate transition prediction position than laminar separation, which gives the transition onset position ahead of experiment value, while aerodynamic forces obtained with both methods agree with those with experiment. Meanwhile, there is a little discrepancy between Langtry and Tomac correlation; however, Toamc correlation can display the separation bubble, which is identical with oil-flow experiment by Selig.

Key words: low Reynolds number, laminar separation, Michel transition criterion, γ-Reθt transition model, transition prediction, E387 airfoil

CLC Number: