Theoretical Analysis on Choking of Convergent Nozzle Flows with Boundary Layers

Transonic Potential Flows in A Convergent–Divergent Approximate Nozzle

In this paper we prove existence, uniqueness and regularity of certain perturbed (subsonic–supersonic) transonic potential flows in a two-dimensional Riemannian manifold with “convergent–divergent” metric, which is an approximate model of the de Laval nozzle in aerodynamics. The result indicates that transonic flows obtained by quasi-one-dimensional flow model in fluid dynamics are stable with ...

Choking of liquid flows

It is well-known that laminar flow of a liquid in a duct is predicted to choke if the viscosity of the liquid increases exponentially with increasing pressure. In other words, the pressure drop in the duct is predicted to become unbounded when the volumetric flow rate reaches a critical finite value. Choking is not observed in practice, however: the reason why is investigated here. It is shown ...

Effects of moderate Reynolds numbers on subsonic round jets with highly disturbed nozzle-exit boundary layers

PSP visualization studies on a convergent nozzle with an

An in-house Pressure Sensitive Paint (PSP) formulation has been developed at the Aero-Physics Laboratory at the University of Manchester. The PSP uses Bathophenanthroline Ruthenium as the luminophore molecule and is incorporated in a sol-gel matrix. Excitation occurs at 400-500 nm and emission at 550-650 nm. The Stern-Volmer plot of the PSP reveals small temperature dependence, which has always...

Anisotropic Adaptation for Transonic Flows with Turbulent Boundary Layers

Simulation of wall-bounded turbulent flows poses significant challenges and requires tightly controlled mesh spacing and structure near the walls. Semi-structured or hybrid meshes are often used for turbulent boundary layer flows. These meshes not only account for complex geometry but also maintain highly anisotropic, graded and layered elements near the walls. However, for engineering flow pro...