TY - JOUR
T1 - Aerodynamics of a highly irregular body at transonic speeds - Analysis of STRATOS flight data
AU - Guerster, Markus
AU - Walter, Ulrich
N1 - Publisher Copyright:
© 2017 Guerster, Walter. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2017/12
Y1 - 2017/12
N2 - In this paper, we analyze the trajectory and body attitude data of Felix Baumgartner’s supersonic free fall through the atmosphere on October 14, 2012. As one of us (UW) was scientific advisor to the Red Bull Stratos team, the analysis is based on true body data (body mass, wetted pressure suit surface area) and actual atmospheric data from weather balloon measurements. We also present a fully developed theoretical analysis and solution of atmospheric free fall. By matching the flight data against this solution, we are able to derive and track the drag coefficient CD from the subsonic to the transonic and supersonic regime, and back again. Although the subsonic drag coefficient is the expected CD = 0.60 ± 0.05, surprisingly the transonic compressibility drag coefficient is only 19% of the expected value. We provide a plausible explanation for this unexpected result.
AB - In this paper, we analyze the trajectory and body attitude data of Felix Baumgartner’s supersonic free fall through the atmosphere on October 14, 2012. As one of us (UW) was scientific advisor to the Red Bull Stratos team, the analysis is based on true body data (body mass, wetted pressure suit surface area) and actual atmospheric data from weather balloon measurements. We also present a fully developed theoretical analysis and solution of atmospheric free fall. By matching the flight data against this solution, we are able to derive and track the drag coefficient CD from the subsonic to the transonic and supersonic regime, and back again. Although the subsonic drag coefficient is the expected CD = 0.60 ± 0.05, surprisingly the transonic compressibility drag coefficient is only 19% of the expected value. We provide a plausible explanation for this unexpected result.
UR - http://www.scopus.com/inward/record.url?scp=85037644367&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0187798
DO - 10.1371/journal.pone.0187798
M3 - Article
C2 - 29216204
AN - SCOPUS:85037644367
SN - 1932-6203
VL - 12
JO - PLoS ONE
JF - PLoS ONE
IS - 12
M1 - e0187798
ER -