Optimization of the gas-liquid damper pin in the aircraft landing gear

Abstract

The gas-liquid damper is the main element in depreciation system of the aircraft landing gear. In this damper, the hydraulic resistance force to the rod motion depends on the working fluid flow rate through the plunger throttle hole, which area is regulated by a pin. If the passage hole area changes, the hydraulic resistance force also changes. Based on formulated criteria for the depreciation quality (energy intensity and dynamic coefficient), the problem of optimizing the pin profile was solved. To describe the damper operation, a mathematical model validated according to the landing gear testing results was used. Geometric parameters of the pin profile are described using the piecewise linear approximation or the cubic spline. To solve the problem of multicriteria optimization, the objective function was used covering a wide range of the aircraft landing weights. The solution was found using numerical integration of the damper mathematical model equations and the global optimization surrogate model. Analysis of the obtained results showed the possibility of reducing the load on the aircraft landing gear and the airframe structure.