COMPUTER-SIMULATION OF THE BI-STABLE VALVE IN THE A340 LANDING GEAR

The increasing use of simulation for both circuit and component analys is in the aircraft industry has come about due to the requirement for acceptable transient as well as steady state performance of aircraft s ystems. The computer simulation package, Bathfp, developed at the Flui d Power Centre, University of Bath, is suitable for investigations int o both of these. Utilities are provided which allow a model of a compl icated system or component to be built up from its elements, which can be introduced to the model library of components so that particular d edicated areas of interest such as flight control actuation systems an d braking and landing gear may be examined in detail. Component models enable the internal details of valves, pumps, motors, actuators and o ther elements to be simulated to a high degree of accuracy. This paper describes the application of the simulation package to perform a deta iled analysis of the bi-stable valve in the A340 landing gear shock ab sorber. In the original design, a malfunction of the valve during impa ct on landing was clearly identified by an experimental test. Parametr ic variations are made in the simulation to identify the possible caus e of the malfunction.