Workshop "Onset of Turbulence and Singular Flows" organised by Henri Benard Pilot Centre, SIG14, SIG35 took place on the 7th - 10th July 2021 at IGESA, Porquerolles Island, France. The workshop was first motivated by two very recent studies:

• the first one is by Berangere Dubrulle and coworkers, oninteracting singularities as solutions of Navier-Stokes equations, or pincons;

• the second is by Yuli Chashechkinon Conventional Partial and Complete Solutions of the Fundamental Equations of Fluid Mechanics in the Problem of Periodic Internal Waves with Accompanying Ligaments Generation

The workshop gathered about 25 participants in presence, with 3 postdoctoral students, and 5 talks were given online. All talks, in presence or not, were followed using zoom. A list of the 12 zoom followers can be obtained from the organisers upon request.

The main organisers:

• Tomas Bodnar, Czech Technical University in Prague, Czech Republic
• Claude Cambon, LMFA, Ecole Centrale de Lyon, France
• Philippe Fraunie, MIO, Universite de Toulon, France

The detailed report from the event will be available in ERCOFTAC Bulletin in a nearest future.