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Transitional Flow in Low-Pressure Turbine

Air density at high altitude is significantly lower than at sea level. As a result, the aerodynamic performance of aero-engines, particularly the Low-Pressure Turbine (LPT) operating under cruise (off-design) conditions, faces substantial challenges. In the context of the unsteady inherent of Turbomachinery flow domain, wake–blade interaction plays a crucial role in determining blade aerodynamic performance. Depending on its characteristics, wake flow can either enhance or deteriorate aerodynamic performance by influencing boundary-layer transition 

mechanisms. This raises important questions

?What are the different transition modes in LPTs domain-
?Is there a passive approach to control transition behavior-

In a research work entitled as “Transitional flow in a two-stage low-pressure axial turbine under different clocking of blades”, published in the journal of Aerospace Science and Technology, we numerically investigate wake–blade interaction and its impact on transition mechanisms in a two-stage axial turbine. The study examines multiple transition modes, including

Separation-induced transition-

Bypass transition-

Reverse transition-

We further analyze wake trajectory as a primary source of unsteadiness using

 3D flow topology (vortex core identification)-

Blade-to-blade (S1) entropy contours-

Five key parameters, including Cp, FSTI, intermittency (γ), Cf (local skin friction coeff.) and “transition-onset momentum thickness Re No.” are employed to characterize wake-induced transition behavior. For those interested in turbomachinery aerodynamics, unsteady flow physics, and transition modeling, the full article is 

:available here

https://doi.org/10.1016/j.ast.2024.109254

.I would be happy to hear your thoughts and discuss further