In Fluent 5 I am performing analysis on a RAE-2822 aerofoil - transonic turbulent case using the k-epsilon model.

I know from experimental data under the conditions I am applying, that the flow transitions to turbulent at about 10% chord.

As the model is set up currently the flow is turbulent (using a turbulent flow model) from the start, i.e. at the far-field. This is distorting the leading edge pressure results.

Is there a way of making Fluent model this flow correctly i.e. only applying the k-epsilon model after 10% chord (or at any position I choose)?

Has anyone got any advice? Thanks

k-epsilon cannot be expected to model transition if this is what you ask - you should at least try RNG.

if you really want to model an abrupt transition from one cell to the neighbour one just split your domain into two fluid zones and turn on "laminar zone" for the first. Then the the k- and the epsilon-equation are frozen inside this zone.