220 likes | 405 Views
Trajectory Code Validation Slides 04/12/08. Trajectory Simulation – Drag Loss. Results: Compare to Shuttle (2029633 kg GLOM): 107 m/s Titan IV/Centaur (886420 kg GLOM): 156 m/s (from SMAD). Chua – 01/31. Trajectory Optimization.
E N D
Trajectory Code Validation Slides04/12/08 AAE 450 Spring 2008
Trajectory Simulation – Drag Loss • Results: • Compare to Shuttle (2029633 kg GLOM): 107 m/s Titan IV/Centaur (886420 kg GLOM): 156 m/s (from SMAD) Chua – 01/31 AAE 450 Spring 2008 Trajectory Optimization
Scott BreitengrossFeb 7, 2008Trajectory group, Delta V Delta V determination, Saturn V comparison AAE 450 Spring 2008
Changes and Assumptions • All stages masses modified to Saturn V • Engine thrust and exit area modified • Burn Time and mass flow rate modified • Stage diameters modified • Assume ΔV_Leo is same *All Saturn V specs provided by http://www.nasm.si.edu/collections/imagery/apollo/saturnV.htm AAE 450 Spring 2008 Trajectory
ΔV Calculations Saturn V Inputs 2362 m/s 36 m/s ~11000 m/s Future Work • Continue on Trajectory Model AAE 450 Spring 2008 Trajectory
Brad Ferris02/21/08Trajectory AnalystModeling DragAssistance provided by Jayme Zott, Kyle Donohue AAE 450 Spring 2008
Modeling • Assumptions: • Atmosphere molecular weight is constant • Angle of Attack is zero • Speed of Sound: a = [γRT]1/2 • Use Mach Number to get CD • Apply Equation for DragD = CD * q * S AAE 450 Spring 2008 Trajectory Optimization
Validation • With function, notice drag behavior • Over most Mach numbers, drag without function is higher Figure by Brad Ferris AAE 450 Spring 2008 Trajectory Optimization
Orbit parameters • Without Function • 762 / 232710 km(periapsis / apoapsis) • Eccentricity: 0.942 • Delta V Drag: 461 m/s • Delta V Total: 10760 m/s • Steering Angles:6,-28,-28 deg. • With Function • 807 / 232477 km(periapsis / apoapsis) • Eccentricity: 0.942 • Delta V Drag: 384 m/s • Delta V Total: 10672 m/s • Steering Angles:6,-28,-28 deg. AAE 450 Spring 2008 Trajectory Optimization
Drag and Time Figure by Brad Ferris AAE 450 Spring 2008 Trajectory Optimization
Junichi (Jun) Kanehara02/21/2008TrajectoryValidation of Thrust in the Trajectory Codes AAE 450 Spring 2008
Test #1 • Procedure • Set Drag = 0 >> Assume No Atmosphere • Calculate for each stage, • using the data from Ariane 4, Saturn V and Pegasus • Compare with the historical data. • Results • The calculated values matched with the historical data!! • (3-5 or more significant figures) Special Thanks to Kevin & Mr. Tsohas for helping us AAE 450 Spring 2008 Trajectory
Test #2 • Full Atmosphere • Exit Pressure and Exit Area were calculated. Thrust in Vacuum Condition Thrust in Sea Level Condition AAE 450 Spring 2008 Trajectory
Backup Slides Ariane 4 Special Thanks to Mr. Tsohas for providing the data AAE 450 Spring 2008 Trajectory
Backup Slides Saturn V, First Stage AAE 450 Spring 2008 Trajectory
Backup Slides Solve for and get Solve for and get Special Thanks to D.Lattibeaudiere for co-working on prop_test.m AAE 450 Spring 2008 Trajectory
Test #1: Delta_V_Thrust_Total Backup Slides • Ariane 4: 10,120[m/s] • Saturn V: 13,470 [m/s] • Pegasus: 8,360 [m/s] AAE 450 Spring 2008
Amanda Briden2/28/08APM, Trajectory GroupBallistic Coefficient Analysis‘measure of its ability to overcome air resistance in flight’1 AAE 450 Spring 2008
Ballistic Coefficient Definition BC: Large Launch Vehicles transonic regimeM = 1.19 @ t = 70s wherem - total massCD- drag coefficient f(M) - calculated by Aerothermal solve_cd.mS – reference area; stage diameter out of atmosphere 10s vertical flight Expect:- Larger BC for more massive launch vehicles our region AAE 450 Spring 2008 Trajectory
BC: Sample MATs Launch Vehicles Conclusions:- Trends are as expected- Our vehicle cannot easily overcome air resistance end of 1st stageS changes Thank you to Jun Kanehara, Elizabeth Harkness, Alan Schwing, and Kevin Kloster for all of their help this week! AAE 450 Spring 2008 Trajectory
Backup Slides Future Work • Optimize final design cases • Write report References: • "Ballistic coefficient." Wikipedia January 18, 2008 February 27, 2008 <http://en.wikipedia.org/wiki/Ballistic_coefficient>. • Longuski, Prof. J. "AAE 450 Spacecraft Design Lecture #6." Purdue University, West Lafayette, IN. • Longuski, Prof. J. Ballistic Coefficient interview. February 20, 2008. • Kloster, Kevin. Ballistic Coefficient interview. February 20-27, 2008. AAE 450 Spring 2008 Trajectory
Steering Angles Used In Analysis AAE 450 Spring 2008 Trajectory