Analysis of Rocket Flights E80 Spring 2008 Section 2, Team 2 Student 1, Student 2, Student 3, and Student 4

Introduction Model and analyze the flights of four different rockets Three bore sizes: –Small: 2 inches –Medium: 2.25 inches –Large: 3 inches Three types of on-board instrumentation: –IMU navigation sensors –Temperature and pressure sensors –Vibration sensors Compare flight data to predictions made using RockSim

Background Vibration rocket –16 Piezoelectric dynamic strain gauges Temperature and Pressure rocket –4 thermistors –Pitot tube pressure sensor IMU rocket –3 accelerometers on orthogonal axes

Background Assigned rockets –Large vibration –Large IMU –Medium temperature and pressure –Small vibration R-DAS acquisition system –Store data on-board (200 Hz sampling rate) –Transmit data wirelessly to a receiver (10 Hz sampling rate)

Vibrational Analysis - Large Predicted modal frequencies Mode Theoretical Frequency (Hz) Theoretical Aliased and Folded Frequency (Hz) 1±537.97± ± ± ± ±92.55

Vibrational Analysis - Large Converting vibrational data to frequency domain

Vibrational Analysis - Large Frequency Response Functions

Vibrational Analysis - Large Comparison of theoretical and experimental modes Mode Theoretical Aliased and Folded (Hz) Experimental Modes (Hz) 1±62.03±54.8 2±82.91± ±92.55±79.64

Vibrational Analysis - Small Spectrum plot

IMU Analysis Most acceleration along z-axis Plotted z-axis acceleration vs. time

IMU Analysis Numerically integrated acceleration data to find velocity vs. time

IMU Analysis Numerically integrated velocity data to obtain position vs. time

IMU Analysis Also used pressure data to obtain a graph of position vs. time

Temperature & Pressure Analysis Found relationship between temperature and resistance of thermistors: Obtained constants during laboratory experiments

Temperature & Pressure Analysis Found relationship between height and pressure: Altitudes were calibrated as zero at the lake bed in Lucerne Valley

Conclusions Apogee for IMU rockets approximately 130 meters FRFs for large vibration rockets determine how rocket responds to input frequency Malfunction in the small vibration rocket’s R-DAS Determined altitude of rocket from pressure readings

Acknowledgements Professor Spjut Professor Cardenas Professors Wang, Yang, and Miraghaie E80 Lab Proctors Rocket Teams

References Student 1, Student 2, Student 3, Student 4. Section 2 Team 2 Notebook. Spring E80 The Next Generation Spring Harvey Mudd College Engineering. Elastic Properties and Young’s Modulus for Some Materials. Engineering Toolbox. Polycarbonate. Answers.com: Technology.

Questions?