A Fully Coupled CFD and Rigid-Body-Dynamics Simulation Tool for Predicting Drag and Lift Characteristics of Irregularly-Shaped Fragments

Debris fragments are a major concern when characterizing the debris environment for both spacecraft and ground-based systems. One of the major technical difficulties in the characterization of debris fragmentation is the uncertainty is predicting the lift and drag characteristics of irregularly shaped fragments. The lift and drag characteristics are functions of Mach numbers, Reynolds numbers, fragment shape and orientation, Kundsen numbers for rarefied gas environment. Currently, there is no general theory for the properties of the lift and drag characteristics of irregularly shaped fragments. In this Phase I proposal, we propose to develop a new fully coupled implicit 3-D CFD and rigid-body-dynamics simulation tool for arbitrary motion of irregular shaped fragments in a wide range of flow conditions. We will address the correlation of drag and lift characteristics and the correlation of these characteristics to other fragment properties for a full spectrum of flow regimes including free molecular, hypersonic, supersonic, transonic, and subsonic flows. We will also determine the motion of the fragments of various shapes. The new simulation tool is expected to be valuable to the development of accurate prediction tools for the aerodynamic lift and drag characteristics of irregularly-shaped intercept fragments.