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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
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Vince Teixeira27 March 2008StructuresNose Cone “Sarah” AAE 450 Spring 2008
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
References • Auman, Lamar M. and Wilks, Brett, “Supersonic and Hypersonic Minimum Drag for Bodies of Revolution.” AIAA 2003-3417, Orlando, FL, June 2003. • 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. 236-242. • Schneider, Steven P., “Methods for Analysis of Preliminary Spacecraft Design,” AAE 450, Spacecraft Design, Purdue University • Aerospace Structural Metals Handbook, 2000 Edition AAE 450 Spring 2008 Structures
Final Nose Cone Design THIS END UP AAE 450 Spring 2008 Structures
Final Nose Cone Masses Nose Cone geometry/mass is a function of third stage diameter AAE 450 Spring 2008
Stagnation Point Heating Analysis Code co-written with Jason Darby AAE 450 Spring 2008
Stagnation Pressure AAE 450 Spring 2008