Research And Simulation Of Steam Catapult Capacity Control System

Steam catapult is one of the most important aviation support equipments in modern heavy aircraft carriers. The catapult is able to greatly shorten the runway needed to make a successful onboard take off for carrier based aircrafts. It also enhances the safety of onboard take off, allows all kinds of aircrafts to take off with full load, which is the foundation of the mighty power of modern aircraft carrier. A steam catapult can be simplified to a steam-drive one way cylinder, the key point of the design is how to control the output energy to ensure the aircrafts launched could reach enough end speed, and at the same time to ensure the variation of launch acceleration would be as small as possible to prevent overload. Therefore, the study of steam catapult capacity control system is of great importance.The comprehensive analysis of C13-1 wet receiver constant pressure catapult is achieved at first, which focuses on the launch engine system. The components of steam-drive part and hydraulic control part are studied separately and also their operation principle, structure parameters, and influence on the energy output are analyzed, based on which the catapult operation process is also analyzed and the key components is found.Based on the structure analysis of catapult, for the steam-drive part of launch engine system, the dynamics model and the thermal-dynamics model of catapult are developed, and then the influence of model parameters on system output is analyzed. The simulation model of this part is developed using AMESim software and the simulation results are analyzed to discuss the key parameters which have great influence on output and how they influence it. For the hydraulic control part of launch engine system, the simulation models of launch valve control system and exhaust valve control system are developed. The structure of uncertain part is analyzed and model parameters are calculated basing on the reference materials. The simulation results are analyzed to study the output of launch valve cylinder and exhaust valve cylinder during their opening and closing operations.At last, the complete simulation model of catapult launch engine system is developed, and the model parameters are adjusted according to the test data of actual catapult to get a precise simulation system of launch engine. The capacity control law of catapult launch engine is analyzed using simulation results and the functions of control parameters are got.