AAE 450 Spring 2008 Vince Teixeira 27 March 2008 Structures Nose Cone “Sarah”

Nose Cone Design History  Initial design consideration: –Low Drag Power-law body: Sharp tip presents heating concern  Thermal Analysis –Stagnation point heating analysis As radius of curvature approaches 0, heating rate approaches infinity (infinite heat transfer to leading edge of nose cone) Simplified analysis using solid, blunted tip configuration  Structural loading –Axial compression Important considerations: –Stagnation pressure –G-loading Result: addition of 8 evenly-spaced stringers AAE 450 Spring 2008 Structures

Heating and Pressure Analysis  Stagnation Point Heating Analysis –Driven by density of fluid, radius of curvature, instantaneous velocity, surface temperature, atmospheric enthalpy –High-altitude/low-density atmosphere drastically reduces heating Still primary concern for nose cone requirements  Pressure Loading –Axial compression of nose cone Atmospheric loading due to stagnation pressure G-loading of solid titanium tip Axial stringers (Aluminum) added to increase strength  Materials –Solid nose tip: Titanium –Remaining surface: Titanium upper half/Aluminum 7075 lower half –Stringers: Aluminum 7075 AAE 450 Spring 2008 Structures

AAE 450 Spring 2008 Structures References  Auman, Lamar M. and Wilks, Brett, “Supersonic and Hypersonic Minimum Drag for Bodies of Revolution.” AIAA , Orlando, FL, June  Santos, W. F. N., “Leading Edge Bluntness Effects on Aerodynamic Heating and Drag of Power Law Body in Low-Density Hypersonic Flow,” AIAA Journal, Vol. XXVII, No. 3, 2005, pp  Schneider, Steven P., “Methods for Analysis of Preliminary Spacecraft Design,” AAE 450, Spacecraft Design, Purdue University  Aerospace Structural Metals Handbook, 2000 Edition

Final Nose Cone Design AAE 450 Spring 2008 Structures

Final Nose Cone Masses Launch VehicleMass (kg) 200g kg kg Nose Cone geometry/mass is a function of third stage diameter AAE 450 Spring 2008

Stagnation Point Heating Analysis AAE 450 Spring 2008 Code co-written with Jason Darby

Stagnation Pressure AAE 450 Spring 2008