Dynamics And Simulation Of Flexible Rockets Pdf May 2026

The cornerstone of flexible vehicle dynamics is the mean axes (or Tisserand axes) reference frame. This body-fixed frame is defined such that the linear and angular momenta due to elastic deformation are zero relative to the frame. In practice, this means the axes follow the average motion of the vehicle, allowing the rigid body dynamics to be cleanly separated from the vibrations.

The accelerometer at station ( x_sens ) reads: [ a_meas = a_rigid + \sum_i=1^N \phi_i(x_sens) \ddot\eta_i ] This corrected acceleration is fed to the guidance, navigation, and control (GNC) system. dynamics and simulation of flexible rockets pdf

To simulate a flexible rocket, one cannot use Newton-Euler equations alone. The industry standard is the Lagrangian approach combined with Modal Analysis. The cornerstone of flexible vehicle dynamics is the

Liquid dynamics are notoriously difficult to model. In simulation, sloshing propellant is often represented as a mechanical analog—a "pendulum" or a "spring-mass-damper" system attached to the tank walls. This simple model predicts the forces the sloshing liquid exerts on the airframe. The accelerometer at station ( x_sens ) reads: