The Influence of a Forward Splitter Plate on Base Pressure and Drag of Wedges

Experiments have been performed to assess the base and total drag reduction due to a forward splitter plate (FSP) on two wedge model shaving semi-apex angle of 12 and 30 deg. Two splitter plates having a length of H and 3.2H (where H represents the base height)respectively were used. The tests were made at a subcritical Reynolds number of 4 x 10 and the wake survey method was utilised to determine the total drag. The results show virtually no changein base pressure due to FSP on both the models. The total drag onthe other hand was about 9 'and 4% lower for the 30 and 12 deg.wedges respectively for the optimum splitter plate. length equal tothe base height. It is suggested that the observed drag reductionis due to lower -surface pressures associated with separated flow13; in the nose region.