P. Kumar

Effect of leading edge shapes on 81°/45° double-delta wing at low speeds

Investigations were performed on an 81°/45° sweep double-delta wing at a freestream velocity of 20 m/s. Experiments consisted of the measurement of forces, static pressures, and surface flow visualizations. Effect of the leading edge shapes of the double-delta wing was studied. Results indicated a strong influence of the leading edge shape on the aerodynamic performance of the body. The increase in the bluntness of the leading edge augments the suction pressure and delays the vortex lift phenomena at higher angles of attack, which in turn enhances the lift over the wing. A reasonable agreement between the experiments and computations were observed.

Side force over slender body with rings at different location at subsonic speed

Investigations have been made adopting experiments and computations on an ogive-nosed slender body at different angles of attack and Reynolds number of 29,000 based on the model base diameter diameter. The results indicated an increase in the side force at large angles of attack, which is mainly due to the presence of asymmetric vortices in the leeward of the body. The inclusion of a rectangular cross-sectioned ring in the initial portion of the body reduced the side force at higher angles of attack. However, significant side force was experienced at lower angles of attack (30° < α < 40°). Use of a ring of 3% height was found to be suitable for reducing the side force at a higher angle of attack. From the results obtained it was observed that a ring if placed at a different axial location alters the flow field and changes the side force at higher angles of attack. Further studies indicated that placing of rings pair at an axial location of 3.5 and 4.5 times the base diameter reduced the side force to a very low value at all the angles of attack for the present shape of body and flow conditions.