A simple model of neutrally stratified boundary-layer flow over complex terrain with surface roughness modulations (MS3DJH/3R)
The MS3DJH series of simple models of flow over low hills and other terrain features described in earlier papers (see Taylor et al., 1983) required that the terrain was of uniform surface roughness. In the present paper, we describe an approximate theory of flow above variations in surface roughness using a similar structure to that established by Jackson and Hunt (1975) for flow over hills. This then allows us to include the calculation of flow perturbations due to roughness variations within a modified version of our model which we designate as MS3DJH/3R. Comparisons are made with alternative calculations for simple two-dimensional flows; and sample three-dimensional calculations are presented. The model retains its essential features of high spatial resolution and low computing cost.