A 3-D SEPARATION MODEL FOR ARBITRARY PLANFORMS
T.S. Beddoes · 1991
A method is presented for the simulation of flow separation on lifting surfaces in 3 dimensions. The procedure is implemented using 3 modules which have been developed for incorporation in a rotor loads program. These consist of an indicial formulation of time dependent lift and moment for attached flow, a separation degree of freedom and a near wake model. Interaction between these modules is effected in a time stepping mode which is capable of reproducing either dynamic response or steady state conditions. A simplification of the treatment of the centre section of swept wings is extended to accommodate wings with arbitrary changes in planform and sweep. Validity of the approach is evaluated by comparisons with experiment and theory using planforms of increasing complexity, comprising rectangular, tapered and swept and finally utilising the tip planform of the BERP rotor. There are implications for the design of advanced tip planforms where the non linear behaviour may be used to advantage.