AeroModeller – June 2018

T

he recent publication of a

book on the jet aircraft designs

proposed by the Focke-Wulf

Flugzeughau AG has stirred my

interest, as such designs were

among the fi rst to be sure of problems

with the compressibility of air at high

speeds. Previously, propeller tips were

among the fi rst to fi nd the problems

caused by compressible fl ow, as the

propeller tip speeds exceeded Mach 0.7.

During WW2, as engine powers grew,

the consequent increase in air-speed,

resulting in “shock stall” with loss of

control, appeared fi rst in aircraft with thick

wings, unsuitable body shapes or in dives

at high altitude.

The classic examples were the Hawker

Typhoon, with a wing section nearly 20%

thick, and the Lockheed Lightning with

its pod-like fuselage. While the tear drop

shaped pod was a low drag shape at low

speed, when combined with the fl ow over

the wing, at high speed the deleterious

eff ects were again due to

compressible fl ow.

Now we have met Isaac Newton before,

his laws of physics being the core for

design of jets and rockets. Newtons

eff orts at fi nding an expression for lift

at low speeds found him in disrepute:

so I was astonished to fi nd his same

lift expression to be widely used above

Mach 5 in the present day! Clearly there is

something about air which is little short

of amazing.

Focke-Wulf Jet Fighters

But fi rst back to Justo Miranda's

comprehensive documentation of

“Focke-Wulf Jet Fighters”, 2018, Fonthill

Publication, ISBN 978-1-78155-644-1.

46 AeroModeller - June 2018

Aerodynamics, Books & More!

From the Armchair...

PART 29: Stuart ’Supercool’ Sherlock is inspired by a new book on Focke-Wulf jet aircraft.

From the Armchair...

You won’t fi nd this “fantasy” 190 Focke-Wulf

jet in the comprehensive new book from

Fonthill Publications! It was from the fevered

imagination of Rob Smith and can be found

as the FF EDF free plan in June 2017 AM.

ARMCHAIR PART 29.indd 46 26/04/2018 14:31