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Write up analysis up until this point
See Parachute Analysis.
Recalculate forces, dynamic pressures, and descent rates for updated rocket
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| LaTeX Math Block | ||
|---|---|---|
| ||
$F=C_k(C_dS)_0\frac{1}{2}\rhov^2$rho v^2$ |
Stress in DGB (Clark and Tanner, 13)
| LaTeX Math Block | ||
|---|---|---|
| ||
$\sigma t=\frac{F_{design}}{\pi D_{disk}}$ |
Ripstop Nylon Cloth MIL-C-7020 (Poynter, 70)
| Fabric, oz/yard | t, inches |
|---|---|
| 1.1 | .005 |
| 1.6 | .006 |
Find drogue Cd
Maydew gives Cd_0 = .53-.58, Dc/D0 = .73, and Dp/D0 = .65 (15).
Clark and Tanner say "It was typically assumed" that Dp/D0 = 2/3 (12). They do not give Cd anywhere, however they cite a number of papers that my give it.
Lingard has charts with Cd vs M for a number of geometric parameters (55-58). They range from .3-.6 in the subsonic range, .5-.2 in the transonic range, and .3-.5 in the supersonic range. I'm not sure what all of the geometric parameters are or what Cd is with respect to.
Size drogue
As of December 12, the mass budget says the rocket will be about 95lb dry.
Pick geometric ratios
Read Clark and Tanner.
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Find suppliers and order textiles
Other tasks
Get design reviewed
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Create master list of construction details
Arrange wind tunnel test
Sources
Lingard. 09_Supersonic Parachute Aerodynamic Testing and Fluid Structure Interaction Simulation_Lingard.pdf. (n.d.). Retrieved from https://solarsystem.nasa.gov/docs/09_Supersonic%20Parachute%20Aerodynamic%20Testing%20and%20Fluid%20Structure%20Interaction%20Simulation_Lingard.pdf
Clark, I., & Tanner, C. (2017). A historical summary of the design, development, and analysis of the disk-gap-band parachute. In 2017 IEEE Aerospace Conference (pp. 1–17). https://doi.org/10.1109/AERO.2017.7943854
Maydew, R. C., Peterson, C. W., & Orlik-Rueckemann, K. J. (1991). Design and Testing of High-Performance Parachutes (La Conception et les Essais des Parachutes a Hautes Performances) (No. AGARD-AG-319). ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRANCE), ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRANCE). Retrieved from http://www.dtic.mil/docs/citations/ADA246343
Potvin, J. (2009). Updating and Upgrading the World’s Database on the Opening Shock Factor Ck. American Institute of Aeronautics and Astronautics. https://doi.org/10.2514/6.2009-2905
Poynter, D. (1984). The parachute manual: a technical treatise on aerodynamic decelerators (3rd ed., completely rev). Santa Barbara, CA: Para Pub.