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Predicting transition with algebraic intermittency function
DOI:10.1063/5.0077513.png)
Abstract
En 中文
An algebraic intermittency function is developed for laminar-to-turbulent transition flow within the framework of Bradshaw stress-intensity factor (ratio of principal shear-stress over turbulent kinetic energy in the boundary layer), which is parameterized with a flow-structure-adaptive variable (eddy-to-laminar viscosity ratio). Naturally, the intermittency inherits the flow-structure-adaptive character and captures various transition phenomena like bypass, separation-induced, and natural transitions when incorporated in an undamped eddy-viscosity transport equation. An additional viscous-production term is added with the eddy-viscosity transport equation to ensure proper generation of eddy-viscosity at the viscous sublayer when computing separation-induced transition over a low-Reynolds number airfoil. Splitting the intermittency into low and elevated free-stream turbulence intensities has the potential to avoid the trial-and-error inconsistency involved in most of the correlation-based transition models for precise computations. The results demonstrate that the proposed algebraic intermittency model is rational and feasible. Published under an exclusive license by AIP Publishing.
Keywords:
LAMINAR-TURBULENT TRANSITION
DIRECT NUMERICAL-SIMULATION
BYPASS TRANSITION
MODEL
FLOW
SEPARATION
REYNOLDS
EQUATIONS
SCHEME

