On 01/05/2015 08:14, The Natural Philosopher wrote:
On 01/05/15 00:42, Nightjar "cpb"@ wrote:
On 30/04/2015 08:44, Simon Brown wrote:


"harryagain" wrote in message
...

"Tim Streater" wrote in message
.. .
...
The difference is that too many of today's idiots believe in magic or
that a bit of development ought to allow us to have solar panels that
could go on the roof of the car or a plane's wings so that the
car/plane needs no other energy source.

Well one already exists.

Not one that can carry several hundred passengers.

What you don't realise is that if some technology could be found to
reduce drag sufficiently, then it wuld be easily possible.

That isn't going to happen now, we have been
doing planes and cars for too long now....

There are ways to reduce drag, such as a micro perforated skin with
suction to remove boundary layer turbulence and create laminar flow.
However, all aircraft are a collection of compromises and that
particular technology isn't really practical, even on conventionally
powered aircraft.


without drag, there would be no lift. The same viscosity that is
responsible for drag is what allows lift to be generated

The aptly named lift dependent drag, which, for a given amount of lift,
can still be reduced by techniques, such as achieving laminar flow over
the lifting surfaces. However, any that does not produce lift is
parasitic drag and the aircraft would be better off without it.


--
Colin Bignell