Dynamic behaviour of the models as a function of input parameters. The red rectangles indicate models with a stellar wind, the blue rectangles indicate models where no wind forms, and the grey rectangles indicate combinations of parameters not tested or where the models fail for numerical reason. For each combination of luminosity and effective temperature the seed particle abundance and piston velocity are varied as indicated by the inset box. See Table 1 for the different values of seed particle abundance n_gr/n_H (a–d).