The rule-of-thumb with hypersonics is believe the exact opposite of your common intuition. A case in point is a flat plate flying at Mach 9 with its surface normal to the free stream velocity vector is perfectly stable. Common intuition says "no way" to that. However common intuition is based upon low speed aerodynamics that has no shockwaves and is driven by surface viscosity, i.e. stall bubbles, vortex shedding, etc. Hypersonic flight is shockwave dominated. In hypersonics, Newtonian impact theory is a very good approximation. However Newtonian impact theory accuracy begins to break down below Mach 6 and is invalid below Mach 2. If Burt Rutan wants to design hypersonic vehicles, he'll have to unlearn his earlier aerodynamic intuition.
Gary
Space/Science » in reply to Rutan's method
Hypersonic aerodynamics can fool an intuitive engineer
The whole thread (41 posts)
- Probable delay in next shuttle launch
- Strike One...
- NASA maybe screwed
- THIS will be the Shuttle's last hurray!
- Be careful what you wish for
- Those guys have already lost the battle
- This stuff is hard to do
- Plus, people forget how long it took to develop Apollo
- Waste Anything but Time
- There was about a 5 year percolation period before Kennedy's speech
- Plus, people forget how long it took to develop Apollo
- This stuff is hard to do
- Those guys have already lost the battle
- Be careful what you wish for
- No shuttle flights until foam loss is understood
- re: Probable delay in next shuttle launch
- Strike One...