On ''spot'' evolution under an adverse pressure gradient (Q2710451)

The authors describe theory and computations of unsteady travelling ``spots'' of spot-like disturbances which allow to formulate an initial value problems for inviscid spot-like disturbances commencing near the onset of an adverse pressure gradient. A transient stage incorporates initial conditions which imply that the effect of adverse pressure gradient becomes significant. After this, the authors describe leading and trailing critical layers which define the spot-like disturbance, and show that these depart from the wall downstream, accompanied by disturbance amplification and mean flow distortion. Finally, the authors consider in detail the interplay of adverse pressure gradient effects with three-dimensionality, nonlinearity and non-parallelism.