Time-Accurate Coupling of Three-Degree-of-Freedom Parachute System with Navier–Stokes Equations

Abstract

A parachute with payload is modeled as a three-degree-of-freedom system suitable for time-accurate coupling with the Navier-Stokes flow equations. The coupled equations of motion are formulated following an instantaneous Lagrangian-Eulerian approach, and solved using Newmark's time-integration method. Flow solutions are computed by solving the Reynolds-averaged Navier-Stokes equations with structured overset grids. A sensitivity analysis is used to check the adequacy of grid and time-step requirements. The time-accurate coupling procedure is validated by comparing the results with a frequency-domain approach. The results are demonstrated for a real parachute system, including a comparison with the results based on the linear theory. Possible instabilities, such as divergence of inclination angle and flutter associated with fluctuating drag force, are predicted. The present work advances the fidelity of analysis procedures beyond those in current use based on loose coupling with the Navier-Stokes equations.

Navier–Stokes Equations-Based Aeroelasticity of Supersonic Transport Including Short-Period Oscillations

“…The well-established Reynolds-averaged Navier-Stokes (RANS) equations, which are computationally feasible with current supercomputers, have been in use for aeroelastic computations for the last three decades [7]. Recently, such efforts have begun to include trajectory motions [8]; for instance, the effect of phugoid motion on stability is studied in [9] using the RANS equations.…”

Aeroelastic analysis of parachute deceleration systems with empirical aerodynamics

“…[24][25][26] Other methods were developed in the context of the immersed boundary method 27 (with application to low Reynolds problems) and the front tracking method. 11 Models using Navier-Stokes equations coupled to rigid body trajectory models have been proposed in Guruswamy, 28 and there are also successful commercial software applications. 14,[29][30][31] The methodology presented in this work is intended for fast aeroelastic simulation of ballistic parachutes.…”

Numerical Study of Surface Pressure Fluctuation on Rigid Disk-Gap-Band-Type Supersonic Parachutes

“…However, it is questionable whether turbulent effects were truly negligible in their cases, especially in terms of unsteadiness of the wake flow and the shock. Guruswamy [12] did three-degree-of-freedom (3-DOF) computations at Mach 0.43 and 2.0. However, he employed a classical numerical flux (which has huge numerical dissipation) with a Reynolds-averaged Navier-Stokes (RANS) turbulence model.…”