Disambigutaion Decomposition of Mean Skin Friction and Heat Flux on Arbitrary-Curvature Surface

TL;DR

This paper introduces a new combined decomposition method for analyzing skin friction and heat flux on arbitrary curved surfaces, revealing energy transfer mechanisms in aerothermodynamics of curved compression ramps.

Contribution

It proposes a novel decomposition approach based on FIK and RD methods applicable to complex surfaces, enhancing understanding of energy transformation in aerothermodynamics.

Findings

Friction decrease is caused by energy injection from adverse pressure gradients.

Peak friction is mainly due to viscous dissipation and influenced by energy transport.

Peak heat flux is primarily driven by viscous dissipation, with enthalpy transport playing a significant role.

Abstract

Since it is difficult to apply the existing method of friction and heat flux decomposition on the complex surface, a combined decomposition method of friction and heat flux with clear physical interpretation is proposed, which is based on FIK and RD decomposition method and can be applied to arbitrary surface. Based on this method, the aerothermodynamic characteristics of bistable states of curved compression ramps are analyzed from the perspective of energy transformation. The results show that the decrease of friction in the interaction region of the attachment state and the minimum values of friction in the separation bubble are all caused by the energy injection of the work by the adverse pressure gradient. The peak friction is mainly induced by the viscous dissipation, and its position is affected by the mechanical energy transport. The peak heat flux is mainly induced by viscous dissipation, and the enthalpy transport of the separation state plays a greater role in the peak heat flux generation than that of the attachment state. These results indicate that reducing viscous dissipation is a potential way for realizing friction and heat flux control simultaneously.