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LaACES High Altitude Ballooning. Atmospheric Density. PROJECT GOALS. To determine the density of the atmosphere throughout the flight using the P and T that we find assuming air is an ideal gas.
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LaACES High Altitude Ballooning Atmospheric Density
PROJECT GOALS • To determine the density of the atmosphere throughout the flight using the P and T that we find assuming air is an ideal gas. • To better understand the effects that freezing temperatures and low pressures can have on equipment through the atmosphere. • To learn about circuits and electronics and attempt a hands on experiment.
Why pressure changes at different altitudes Atmospheric pressure reduces with altitude: -Due to gravity -The gravitational attraction between the earth and air molecules is greater for those molecules nearer to earth than those further away -Molecules further away from the earth have less weight but they are also 'standing' on the molecules below them, causing compression http://www.npl.co.uk/pressure/faqs/atmosaltitude.html
Density Simple density formula • ρ (rho) - is the density of the substance, measured in kg m^3 • m - is the mass of the substance, measured in kg • V - is the volume of the substance, measured in m^3 Boyle’s Law R - is the universal gas constant - we used 0.000082057 m^3/atm*K m - is the molar mass (in our we use air) kg P – pressure atm T – temperature K ρ – density kg/m^3
Payload Design • Flight Control Unit: BalloonSAT • Power Source: One 9V Lithium Battery • Polystyrene insulation for structure • We choose to do a double box design instead of using the Polystyrene insulation we used thin foam board because rigidity and thermal characteristics. • We put polystyrene inside our small box to hold our BalloonSAT in place and in the inside of the bigger box to also hold the small box in place and provide stability on the impact. • We put our pressure sensor onto the BalloonSAT and the temperature sensor in a little hole that could read the outside temperature of the box, yet still be insulated.
AUTOCAD DRAWINGS INNER BOX
AUTOCAD DRAWINGS BIG BOX
Data Acquisition • Intervals • Our payload was set to take 400 data points • It read data every 36.05 secs. • Set to last 4 hours • Retrieved • We recorded data for 3 hrs 30 mins • We got about 250 good data points • Our payload reached a 100000 feet
Flight Summary • The flight was a little fast, but I still had some good readings. • Our results were good and nothing seemed to go wrong except for some of the temperature readings. • The pressure readings turned out great! • Temperature readings ended up decreasing as the payload descended. This could have been due to the increase in velocity due to technical eras in the decent down once the tether balloon burst. • I was expecting the temperatures to increase on the decent, but I was wrong. • Density retrieved was a bit different than what we expected due to sudden temperature decreases.
Conclusion • Pressure Results turned out great! • Temperature Results seemed to have read different to what I expected. • Density was close to my expected. • Our final goal was reached and everything worked!!! • Great learning experience and happy to be a part of this program.
Acknowledgements • CSBF • Dr. Guo • Dr. Guzik • Dr. Wefel • Mr. Giammanco • Mr. Ellison • Jeff Kornuta • NASA • AND Clovis for keeping my payload in order on the flight!!!!!
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