Side force on an ogive cylinder: Effects of control devices

This study is an extension of our earlier work (Luo, S. C., Lim, T. T., Lua , K. B., Chia, H. T., Goh, E. K. R., and no, Q. W,, "Flowfield Around an Og ive/Eiliptic-Tip at High Angle of Attack," AIAA Journal, Vol. 36, No. 10, 1 998, pp, 1778-1787), which examined the effectiveness of using an elliptic tip to control the side force acting on an ogive cylinder. In that study, o nly one tip was considered, and thus the effect of tip eccentricity on the side force was not known. In the present study, we examine another elliptic tip of a smaller eccentricity to get an insight into how tip eccentricity affects the local and overall side force distribution. Our measurements sho w that, although the smaller eccentricity tip has a side force distribution similar to that of the larger eccentricity tip, there are some major diffe rences in their Row characteristics. For example, the larger eccentricity t ip is found to reduce the onset angle of attack and delay the disappearance of the side force to a higher angle of attack. Furthermore, when alpha app roximate to 60 deg, only the lower eccentricity tip displays a hysteresis e ffect in its side force distribution. To the best of our knowledge, this ph enomenon has not been observed on an elliptic tip before, even though a sim ilar phenomenon has been observed on a conical body with a rounded tip when the cone was subjected to unsteady bleeding.