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Size: 1148
Comment:
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Size: 1183
Comment:
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| Deletions are marked like this. | Additions are marked like this. |
| Line 8: | Line 8: |
| . 1a: $ \dot Q_c = 20 \rho^{1/2} \left( V \over 1000 \right)^3$ Btu/ft^2^-s | . 1a: $ \dot Q_c = 20 \rho^{1/2} \left( V \over 1000 \right)^3$ Btu/ft^2^-s convective power |
| Line 10: | Line 10: |
| . 1b: $ \dot Q_r = 6.1 \rho^{3/2} \left( V \over { 10 000 } \right)^{20} $ Btu/ft^2^-s | . 1b: $ \dot Q_r = 6.1 \rho^{3/2} \left( V \over { 10 000 } \right)^{20} $ Btu/ft^2^-s radiative power |
| Line 24: | Line 24: |
| . Metric 1a: $ \dot Q_c = $3.53e-4$ \rho^{1/2} V^3 $ | . Metric 1a: $ \dot Q_c = $ 3.53e-4 $ \rho^{1/2} V^3 $ |
| Line 26: | Line 26: |
| . Metric 1b: $ \dot Q_r = $3.32e-71$ \rho^{3/2} V^{20} $ | . Metric 1b: $ \dot Q_r = $ 3.32e-71 $ \rho^{3/2} V^{20} $ |
Hypervelocity Drag
Based on Trajectory Optimization for an Apollo-type Vehicle under Entry Conditions Encountered During Lunar Returm by John W. Young (famous astronaut) and Robert E. Smith Jr., May 1967, NASA TR-R-258, Langley Research Center.
Equations on Page 5 in Foot-second-slug-BTU :
1a:
Qc Btu/ft2-s convective power
=20
1
2
V1000
3 1b: \dot Q_r = 6.1 \rho^{3/2} \left( V \over { 10 000 } \right)^{20} Btu/ft2-s radiative power
- Equations assume an effective nose radius of 1 foot
Equations from Shock Layer Radiation During Hypervelocity Re-Entry by Robert M. Nerem and George H. Stickford, AIAA Entry Technology Conference, CP-9, American Institute of Aeronautics and Astronautics, Oct. 1964, pp 158-169.
Density in slugs/ft3: multiply kg/m3 by 1.9403203e-3
Power in Btu/ft2-s: multiply by 11350.54 to get W/m2
Velocity in ft/s: divide m/s by 0.3048
Metric equations:
Metric 1a: \dot Q_c = 3.53e-4 \rho^{1/2} V^3
Metric 1b: \dot Q_r = 3.32e-71 \rho^{3/2} V^{20}