Dynamics of a regulation mechanism of variable geometry

This research is motivated by the functional demands of mode selector valves in variable cycle engines, leading to the design of an innovative eight-sector, over-constrained regulation mechanism. It employs eight curved-plate links arranged symmetrically to convert rotational inputs into smooth reciprocating translational motion of a movable octagonal ring. This kinematic configuration enables the precise and repeatable positioning essential for reliable mode selector valve operation. A comprehensive dynamic analysis of this multi-rigid-body system is then undertaken, serving a dual purpose. First, it establishes the theoretical foundation for accurately determining the external loads experienced by the mechanism under various operating conditions. Second, it supports the development of a control algorithm capable of computing the driving forces required to achieve the desired open/close motion. Together, these capabilities form the basis for reliable and efficient actuation of the mode selector valves within a variable cycle engine environment. Building upon a prior kinematic analysis of valve operation, this study investigates the dynamics of the over-constrained system. The dynamic model is formulated using momentum and force screws, a screw mechanics approach that preserves all the strengths of the Newton-Euler method while offering a key computational advantage. It eliminates the need to derive and solve second-order differential equations of motion from positional data. As a result, the implementation code is remarkably concise and straightforward. This efficient methodology provides a simple yet powerful tool for multi-rigid-body system dynamics. Its clarity and computational economy position it for broad adoption in future simulation software dedicated to complex mechanical systems.