Quote:
Originally Posted by ion_berkley View Post
OK I'll bite since I design RADAR stuff amongst other things.
A quick "back of the fag packet calculation" gives me the following:
Lynx rotor disc diameter (as an example): 12.8M
Lynx blade tip speed: 700 feet/sec = ~ 214M/S
Centripetal Acceleration = (v*v)/r = (214 * 214)/6.4 = 7155 M/S^2
i.e 70g constant acceleration.
Err , maybe need to get your cigarette packet checked
Is 7155m/s^2 ~= 70g ? (More like: 700g)
i can understand that valves might have an issue at 700g, but why would a chip care about being at 700g ?
Excellent catch mate! What's a factor of 10 between friends!
You asked about acceleration and chips...well likely the chips themselves are not the weakest link, but I can only imagine that such cyclical stress would be very detrimental to reliability and lifetime. Whats trickier is keeping everything rigid and planar, bearing in mind all this technology is generally optimized for its electrical qualities rather than mechanical, unlike the composites and alloys used in blade construction, many of the components used in these types of circuits contain fine, hair line filaments of wire or resonating crystals internally for example. Just because R&D has worked out how to put a guidance system into an artillery shell, doesn't make that technology commodity, cheap, or even attractive. At the end of the day, whilst "cost is no obstacle" technologies had there place in the military of the 50's and 60's, thats not the case today.
As for patents, well I have a bunch. I doubt many of the protected technologies in them will ever see commercial success, but its a form of insurance policy when it all occasionally works out.
I think it boils down to this. If you really have an application that requires this level of RADAR functionality then you build it in the contemporary AESA style, conformal with the structure of the aircraft. I've got to believe that the material and mechanical technology that goes into blade design is already difficult enough that it would require enormous justification to add this type of complexity even before we consider how much harder it makes the job of the RADAR design team.