Transition to turbulence as a result of chaotic distortion of vortex shedding

The equations of multimoment hydrodynamics supplemented with stochastic terms are used for numerical simulation of chaotic distortion of regular regimes in the problem on flow around a solid sphere. The influence of disordered perturbations arising in the medium due to external influences is investigated. The loss of stability is accompanied by a qualitative change in the behavior of flow. Each perturbation forces the unstable flow to behave purely individually. The possibility of interpreting each of the unstable flows in terms of some average hydrodynamic values passes away. This behavior is called the butterfly effect. Independence in the behavior of disordered perturbations disappears. Conservation laws force disordered perturbations to adapt their behavior in time and space to the behavior of hydrodynamic values. A change in the behavior of disordered perturbations leads to chaotic distortion of both the regular flow in the recirculating zone and the regular regime of vortex shedding. Distortion of regular regimes creates a turbulent flow pattern in the wake behind the sphere. Vortex shedding is called the regular component of turbulence. Disordered perturbations are called the chaotic component of turbulence. The loss of stability is responsible for the growth and accumulation of disordered perturbations in the wake behind the sphere. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study investigates the chaotic distortion of regular regimes in the flow around a solid sphere using multi-moment hydrodynamics equations with stochastic terms. It explores the influence of disordered perturbations, loss of stability, behavioral changes in flow, butterfly effect, adjustment of disordered perturbations, and the relationships between the regular and chaotic components of turbulence in the wake behind the sphere.