Launch trajectory simulation and flight experiment of small air-launched UAV

In order to increase the combat radius and flight time of the sub-aircraft, low-cost sub-aircraft are used to carry out reconnaissance and strike missions. The unmanned carrier aircraft transports the unmanned sub-aircraft to the destination and launches the sub-aircraft from the launch cylinder. During the launching process, small air-launched foldable UAVs are susceptible to carrier's airflow interference, which affects safety and stability. In order to study the separation process of sub-aircraft launching and avoid the risk of collision, XFlow software was used to simulate the launching process under the working condition of no side wind, backward horizontal launching, carrier cruising speed of 40m/s and launching speed of 5m/s. The simulation recorded the trajectory of the sub-aircraft dropping, and the data showed that sub-aircraft could be separated safely. From the section velocity nephogram and surface velocity nephogram of the flow field during ejection, there is obvious interaction between the sub-aircraft and the trailing edge of the carrier, but the sub-aircraft does not have much influence on the flow field near the surface of the carrier . Under the same working conditions, an air-launch separation test was carried out. In the launching process, the carrier aircraft is basically not affected by the sub-aircraft separation throughout the whole process, while the sub-aircraft is affected by the flow field of the carrier aircraft's wing in the initial stage of placement, which produces a certain degree of interference, and there are fluctuations of no more than 10° of pitch angle and roll angle within 2s out of the launch cylinder. With the sub-aircraft gradually moving away from the carrier, the interference of the sub-aircraft by the carrier is gradually weakened, and safe separation can be achieved.