Renormalisation group theory for two problems in linear continuum mechanics

We consider the problems of: (1) the stress field in an infinite wedge when a moment is applied at the tip, and (2) the flow of an inviscid incompressible fluid past an infinite wedge. Both problems are linear, but nevertheless exhibit anomalous dimensions for wedge angles, α, larger than a critical value αc. In (1) it is the stress field and in (2) it is the velocity potential which can have anomalous power law behaviour in distance from the tip. We use these problems as simple examples to illustrate how partial differential equations can be solved using the renormalisation group.