Aerodynamic Effects of External Camera Pods and Launch Lugs on a Target Missile Configuration

Computstional Fluid Dynamics is employed to predict aerodynamic coefficients for the second-stage configuration of a missile defense target missile. Models consist of the clean vehicle with fins and two additional models that include rail launch lugs and externally mounted rear facing camera pods. Analyses are performed to estimate wind tunnel test measurement requirements and to assist in planning of the wind tunnel test matrix. Postwind tunnel predictions for the clean configuration show excellent comparison to reduced test data. Both predictions and test measurements indicate that the protuberances contribute an additional axial drag to the clean missile configuration of over ten percent. I. Introduction HE Missile Defense Agency has developed a cost-effective target that can be used to assess missile defense capabilities. The Aegis Readiness Assessment Vehicle-Group C (ARAV-C) is a member of this target vehicle class. This paper documents the prediction of aerodynamic coefficients using CFD models for the ARAV-C second stage. Predictions are made for several points along a proposed flight trajectory as a pre-wind tunnel exercise to estimate effects required for measurement and to assist in planning of the test matrix. Post-wind tunnel predictions are made and compared to reduced test data. Favorable comparison resulted in additional computations requested to extend the wind tunnel data to higher Mach numbers for use in 6DOF simulations. Three separate models are generated: the clean vehicle with fins; a second with the addition of two externally mounted camera pods with no launch lugs; and a third that includes the addition of launch lugs with no camera pods. Predictions using the clean configuration and the configuration with camera pods at four roll angles and eight Mach numbers with angle of attack (AOA) set at 3° are made. Additional computations are made using all three configurations. Nineteen wind tunnel comparison computations are completed. A total of 131 3D viscous CFD computations are performed.