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

Abstract

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.

Rolling Moment of Slender Body at High Incidence for Air to Air Missile Rocket Applications

“…Since the flow appears to be in a quasi-steady state at high angles of attack 6 , hence the measurement was made for a time of 5 s with a sampling frequency of 500 samples/ second. To reduce the side force, a rectangular cross-sectioned circumferential ring having a width of 2 mm and variable height was used [5][6][7][8] . An effort was made to obtain the effect of rings on the rolling moment of the slender body.…”

“…The study of the side force over a slender body at high angles of attack has been under consideration since the 1950s [1][2][3][4][5][6][7][8][9][10][11] . Slender bodies with a pointed nose subjected to fly at high incidence experience a large side force and yawing moment.…”

“…Kumar & Prasad [6][7][8] conducted experiments and computations on an ogive nosed slender body and showed that only the initial portion of the body was responsible for the generation of the large side force of the body at high angles of attack. Use of a rectangular cross-sectioned rings place at different locations was found to reduce the side force drastically.…”

Effect of a Circular Ring on the Side Force of a Cone-Cylinder Body

“…Investigations on similar Reynolds number are reported in the literature and have been previously discussed. Based on the results reported by Kumar and Prasad (2016b;2017) and Lua et al (2000) for ogive-nosed slenderbodies, a rectangular cross-sectioned ring reduced the side force at different α for the case of a cone-cylinder body, type of body expected to have lesser axial force at lower angles of attack, which, in turn, can reduce the drag. However, the flow can be extremely complicated over a cone-cylinder body during maneuvers when it experiences high angles of attack and low Reynolds number.…”

“…Leu et al (2005) showed the decrease in the side force using microballoon actuators over a cone-cylinder body. In recent times, experiments and computations carried out by Kumar and Prasad (2017) showed that the use of rings reduces the side force over an ogive-cylinder body. Based on the literature, it is evident that slender-body with conical nose has the advantage of lower axial force and drag in comparison to the other nose shapes.…”