Hypersonic Design Reduces Drag -AVWeek blog entry

[DSE]

Northrop Grumman has been awarded a US patent (number 7828243) for a hypersonic aircraft configuration with combined-cycle propulsion that promises reduced drag and weight for increased performance.

http://www.aviationweek.com/aw/blogs/aviation_week/on_space_and_technology/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=a68cb417-3364-4fbf-a9dd-4feda680ec9c&plckPostId=Blog%3aa68cb417-3364-4fbf-a9dd-4feda680ec9cPost%3a71608881-db9e-456b-824d-2057963ef295&plckScript=blogScript&plckElementId=blogDest

 

[RanulfC]

Ooookay.... the "reason" for the over-under design was to allow using a single inlet over having an inlet for each engine and was designed to reduce drag....

How is adding another set of inlets "reducing" drag exactly? The patent makes the "point" that intake covers for the turbojets can be used as compression and expansion ramps but I'm not really seeing how that's going to help drag all that much over internal covers?

Randy

 

[DSE]

Ooookay.... the "reason" for the over-under design was to allow using a single inlet over having an inlet for each engine and was designed to reduce drag....

How is adding another set of inlets "reducing" drag exactly? The patent makes the "point" that intake covers for the turbojets can be used as compression and expansion ramps but I'm not really seeing how that's going to help drag all that much over internal covers?

Not that I get the patent, but my thought is just take the over/under concept and turn it on its side. Hence reducing the overall cross-sectional area of the vehicle, which definitely helps with transonic drag. Can you get a vehicle that still closes over the mission, is my question?