I emailed my father about this and without referencing this is what he wrote.Hope it helps.
A laminar-flow wing section(airfoil) is shaped so that the air flows over it in uniform layers(i.e in laminars) without any outward cross-flow that creates turbulence and,therefore,drag.
Any wing section has some laminar flow that is maintained until just aft of the maximum thickness position when it slows down and starts to separate,creating cross-flow,instead of following the wing contours.Compared with a conventional wing airfoil,the thickness point of a laminar-flow airfoil is moved further aft-to,say,70% chord instead of 30% chord-so that laminar flow may be maintained to perhaps80% chord.
Laminar flow cannot be maintained to 100% chord without some means of sucking the boundry-layer flow down onto the wing surface,such as using a porous surface through which the air is drawn to be vented overboard.Alternatively,air may be drawn in through a slit near the leading edge and expelled through another slit near the trailing adge to re-energize the slowing airflow.This boundry-layer control technique has been done experimentally(notably by Handley Page back in the 50's),but is impractical for operational aircraft since the small holes or slits tend to become plugged by insects,ice,rain,grease,dirt,etc.Also,an insect or bird that sticks to the leading edge produces a wide V-shape wake behind it that destroys laminar flow(and therefore lift) over that part of the wing.
Natural laminar flow,obtained by careful shaping,is very effective and may be applied to the fuselage from the nose back to the wing.The best example of this is the Dornier 328 turboprop which has fairings added to the fuselage cross-section.I thought that this might have been achieved so,when I attended the 1992 Berlin Air Show,I asked the Dornier cheif designer if that was the case,and he confirmed it was so.(He was very pleased that someone had realised what had been done.)
A laminar-flow section--or any other high-speed wing profile--may be symmetrical or near symmetrical to minimise cruising drag.Lift is obtained by increasing the angle of attack so that the air moving over the top of the wing has further to travel than air passing underneath it and so it speeds up to cause lift.
For lower-speed aircraft,it is usual to set the wing at an angle of incidence to generate extra lift for takeoff when the aircraft is heaviest.If this fixed angle is too large,then the aircraft will fly nose-down in cruise which effectively increases fuselage cross-sectional area and thus creates profile drag.(The classic case was the Armstrong Whitworth Whitley bomber.)
Nowadays,when any desired engine power is available for take-off,use of full power combined with wing flaps permits the wing to be set at a small angle of incidence not far from that angle of attack which is needed for cruising flight where the aircraft spends most of its time.Likewise,wing area is a compromise between the bare needs for cruise and the size needed for take-off and landing.Here,speed range is the key.For a light airplane that stalls at 60 knots and has a top speed of 140 knots,the range is small.But in a Mach 2 fighter,the speed range is very large so engine afterburning is used in combination with leading-and trailing edge flaps for take-off,while some special means of creating lift(e.g blown flaps) is needed for landing.Even then,it may be necessary to use a drag parachute and an arrestor hook(e.g Lockheed F-104 Starfighter) connected to cables that drag paddles in water channels on either side of the runway.
Another way to obtain laminar flow is to construct the wing so that--like a dolphin or manta ray swimming--it changes its shape according to speed.This is a dificult thing to do and so far is still experimental.In great confidence,I was told about this "adaptive skin" technology in 1970 when I was helping the corporate vise-president of engineering,Al Cleveland,to write his Write Brothers Lecture that year for the American Institute of Aeronautics and Astronautics.This year,a test aircraft was flown for the first time--more than 30 years later--and it's still nowhere near being applied practically.
