Numerical simulation of K-, N- and O-regime boundary-layer transition at early nonlinear stage
Journal Title: INCAS BULLETIN - Year 2019, Vol 11, Issue 3
Abstract
Boundary layer transition is usually associated with the amplification and breakdown of three-dimensional waves (3D waves). However, the details of the development of 3D waves in different transition regimes are not well resolved. The present study attempts to examine the transition process at early nonlinear stages of K-, N-, and O-regimes by the solution of nonlinear parabolized stability equations (NPSE). The spatial and temporal variations of streamwise velocity are compared at the one-spike stage. Timelines and material surfaces are presented using Lagrangian tracking method. The development of 3D waves are observed to contribute to the upward lift and downward sweep of flow behaviors, causing inflectional regions in the boundary layer. The evolution of material surfaces reveals that the nonlinear 3D wave manifests as a warped wave front in the near-wall region and as a soliton-like structure at the upper region of the boundary layer. The 3D wave structure is hypothesized as a soliton-like coherent structure. Markedly similar flow behaviors are observed between the regimes, which indicates a similar underlying physical mechanism.
Authors and Affiliations
Xian-Yang JIANG, Cunbiao LEE
Keywords
Related Articles
- EP ID EP630933
- DOI 10.13111/2066-8201.2019.11.3.7
- Views 92
- Downloads 0
Preliminary Numerical Studies for the Improvement of the Ventilation System of the Crew Quarters on Board of the International Space Station
The current concept of Crew Quarters (CQ) aboard the ISS has several issues as recorded by NASA and ESA, the most important ones pertaining to the noise levels and the accumulation of CO2. Currently, 13% and 6%, respecti...
Sustainable development – the key for green aviation
The aviation industry has always been seeking the technological progress that will optimise the economic, operational and environmental way of flying. In the first part of this study the author describes the impact of th...
A Neural Network Controller New Methodology for the ATR-42 Morphing Wing Actuation
A morphing wing model is used to improve aircraft performance. To obtain the desired airfoils, electrical actuators are used, which are installed inside of the wing to morph its upper surface in order to obtain its desir...
Experimental research regarding the performance of small axial turbines
This paper continues research of the authors and presents some theoretical aspects regarding the maximum power extract from the wind turbines, the optimal incidence angle, the best twisting of the blade and experimental...
Analysis of traditional Global Distribution Systems vs. New Distribution Capability
The development of airline services distribution from computer reservation to global distribution systems experiences nowadays a novel transformation based on an improved approach and higher benefits for all actors invol...