|Acquisition Program: ||MDA/SE|| Objective: ||Develop an innovative technique to integrate plume, hardbody, and trajectory parameters together to determine their resulting dynamics and signature implications.
|| Description: ||The signatures due to missile system operation arise from both steady and un-steady propulsion related events. In particular, there are a number of transient events, such as missile staging, that involve the interaction of an exhaust plume with a moving hard body. These are highly complex events to model as they require a time-dependent description of the interaction of the plume with the moving hard body that includes high spatial resolution of both the plume and hard body and 6DOF (Degrees Of Freedom) trajectory models of the plume source and moving hard body to capture the complex transient scene dynamics. In addition, both the heating of the hard body due to plume impingement and the resulting plume shocks must be accurately treated in order to compute a realistic event signature.
There are no available models that currently treat this problem with the fidelity required for missile system design and the analysis of signature data obtained from surveillance satellites and field measurement programs. However, for high-altitude applications (above ~90km), the Direct Simulation Monte Carlo (DSMC) computational approach is ideally suited for handling the geometric and time-dependent complexities of this problem. Specifically, the Spacecraft/Orbiter Contamination Representation Accounting for Transiently Emitted Species - Parallel Version (SOCRATES-P) DSMC code, recently developed under a Common High Performance Computer Software Support Initiative (CHSSI) effort, is fully parallelized, treats time-dependent flows, and includes adaptive gridding. SOCRATES-P provides a solid foundation for adding the additional capabilities needed to treat the plume-hard body interaction problem. The additional capabilities include integration of a 6DOF description of the plume source and hard body -- including the calculation of the plume induced forces and body surface heating.
|| ||PHASE I: The contractor will formulate the overall approach, implement a simplified version into SOCRATES-P (or equivalent DSMC flowfield-signature code) that captures the key physics, and demonstrate the approach for a simplified but representative scenario of interest.
|| ||PHASE II: The contractor will develop a fully functional capability within SOCRATES-P and validate the model against available field data signature measurements. SOCRATES-P will be available as GFE for the phase II effort.
|| ||PHASE III: The model would be used in the design of missile systems and missile warning and surveillance sensors and in the analysis of data from surveillance platforms.
|| ||PRIVATE SECTOR COMMERCIAL POTENTIAL: By creating general ways of handling transient events, this effort will extend the capability of SOCRATES-P to commercial and research applications such as chemical etching and chemical vapor deposition, micro-thrusters, micro-electromechanical systems (MEMS), astrophysics, surface chemistry, satellite contamination, and reentry vehicle modeling.
|| References: ||
G. A. Bird, “Molecular Gas Dynamics and the Direct Simulation of Gas Flows”, Clarendon Press, Oxford, 1994.
J. Elgin and L. Bernstein, “The Theory Behind the SOCRATES Code”, Phillips Laboratory Technical Report, PL-TR-92-2207 (1992).
M. Braunstein and J. A. Cline, “Progress on Parallelizing a General Purpose Direct Simulation Monte Carlo (DSMC) Code for High Performance Computing Applications” AMOS 2003 TECHNICAL CONFERENCE, 10 September, 2003
|Keywords: ||Plume, Hard Body, Signature, High Altitude, Flow Field, Model|