| Abstract [eng] |
The aim of this project is to perform an aerodynamic analysis of a rocket target by using CFD and after that to determine its external ballistic characteristics. In the theory part a brief review of man portable air defense systems is made and their main technical parameters are presented. Then virtual reality simulators and aerial targets used for MANPAD operator training are presented. Coordinate systems were selected to describe the external ballistics of a rocket target. Forces and moments acting on a rocket during the flight are presented. A mathematical model was selected to represent rocket target flight in the longitudinal plane. In the analysis part of the project, a geometry of the rocket target was created in CAD software. The nose cone geometry of Von Karman ogive was selected, because of low drag in the speed range in which the rocket target is operating. Then, solid rocket motors „RM-12K“ were chosen for a propulsion unit of a rocket. Experimental results of the „RM-12K“ thrust profile and other parameters were analyzed and implemented in external ballistics simulations. Aerodynamic analysis was performed with „Ansys Fluent“. Because of the separated flow region behind a boattail part of a rocket „SST k-ω“ turbulence model was selected. After mesh sensitivity analysis drag coefficient values were determined in a Mach range of 0.1–2. Then, the external ballistics of a target with three different propulsion unit configurations were analyzed. In the first configuration all three solid rocket motors „RM-12K“ are ignited at the same time, and a maximum range of 5467 meters is achieved. A maximum speed of 1.2 Mach is reached after 3 seconds in flight. In a second configuration, only one solid rocket motor is ignited initially and after 6.5 seconds two more are started, and a maximum range of 5892 meters is achieved. In a second configuration, the maximum speed of 1.09 Mach is reached after 10 seconds in flight. In a third configuration, two solid rocket motors are ignited at the beginning, and the third motor is ignited after 13.5 seconds. A maximum flight range of 7075 meters is achieved. In a third rocket configuration, a maximum speed of 0.84 Mach is reached after 17 seconds in flight. |
