Casademunt i Viader, JaumeArmengol Collado, Josep-Maria2019-09-132019-09-132019-01https://hdl.handle.net/2445/139978Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2019, Tutor: Jaume Casademunt ViaderTurbulence in active fluids has been proposed as a new universality class of turbulence. However, the mechanisms governing these flows are poorly understood. In this work, we study numerically the formation of uni-dimensional patterns in a minimal model for an active polar nematic fluid, for arbitrary values of the ow alignment coeffcient v. In addition, we determine analytically the linear stability of the asymptotic states, as a function v. We describe the complete bifurcation diagram for uniform states in 1D and show the existence of transversal (2D) instabilities, in particular in the so-called flow alignment regime jvj > 1. This result shows that the secondary instabilities leading to turbulence are not specifc of the case v = 0, thus reinforcing the conclusion that active flows constitute a new universality class of turbulence.5 p.application/pdfengcc-by-nc-nd (c) Armengol, 2019http://creativecommons.org/licenses/by-nc-nd/3.0/es/TurbulènciaFormació de patrons (Física)Treballs de fi de grauTurbulencePattern formation (Physical sciences)Bachelor's thesesinfo:eu-repo/semantics/bachelorThesisinfo:eu-repo/semantics/openAccess