Evolution of complex singularities in Kida-Pelz and Taylor-Green inviscid flows

The analyticity strip method is used to trace complex singularities in direct numerical simulations of the Kida-Pelz and Taylor-Green flows, performed with up to 20483 collocation points. Oscillations found in the Kida-Pelz energy spectrum are attributed to interferences of complex singularities. A generalized least-square fit that separates out the oscillations from the measure of the width of the analyticity strip δ is introduced. Using the available resolution, δ is found to decay exponentially in time up to t=1.25. It is argued that resolutions in the range 163843-327683 (within reach of the Earth Simulator) are needed to really probe the Pelz singularity at t∼2.