Correlation of the detachment of two-dimensional turbulent boundary layers

Abstract

An improved single-variable correlation is developed for incipient and full detachment, and for reattachment ,of turbulent boundary layers on two-dimensional surfaces. The correlation is shown to agree with 1) the wallwake law of Coles; 2) the criterion for detachment of Sandborn and Kline; 3) a large amount of old flowvisualization data; and 4) new measurements of time-averaged fraction of forward flow. Relationships among the correlation, the underlying physics, and the implications for computations are discussed. The results clarify long-standing confusion between incipient and full detachment of turbulent boundary layers with regard to both correlation and computation.