Optimal Tiltrotor Solution

Advanced Rotor Blade Technology

New Concept Rotor – the VTOL Enabler

Both collective and cyclic pitch control can be discarded and replaced by COLLECTIVE AND CYCLIC BLADE TWIST CONTROL. They will do the same job on a higher (much higher!) level.

Cyclic Control of Rotor Blade Twist

· Superior to Traditional Blade Pitch Control

· Flight Envelope Boost ­­­­­

· Optimal Tiltrotor Solution

Morphing characteristics:

· Design allowing to perform close to the optimal ZERO RESISTANCE DEFORMATION (ZRD);

· Low inertia & low friction moving parts – carbon fibre, Teflon & Kevlar – all making use of their best features.

How To Build a Record-Breaking Tiltrotor Aircraft?

A very current question: How to build a record-breaking tiltrotor aircraft?

Short answer: by solving the rotor-blade issue.

Longer answer:

Introducing variable twist of rotor / propeller blades makes it possible to

a) achieve helicopter-level lifting performance;

b) achieve the maximum cruising speed a subsonic aircraft can achieve;

c) save lives of pilots and crew by excluding flight regimes with partially (sometimes even with fully) stalled blades.

Variable Twist Propellers for Aviation

Stallfree Technology = Blade Twist Control

See full detail in the eBook:

https://1drv.ms/b/s!AsD1VBemxG3AzVAR7g1DPMF80nUX?e=4effCk

1. Alignment

Implementation of the Stallfree Technology provides that

a) while both axial speed and RPM vary in

reasonably wide ranges

b) all blade sections (more precisely: chord

lines of all the sections)

c) of a propeller, rotor, or a fan

d) are kept aligned with the direction of the

resulting wind

e) along the whole working radius.

2. Proof

Based on the mechanical features of Stallfree Technology, the presence of the above alignment has a mathematical proof obtained by the application of the Simple Blade Element Theory.

Since the Simple Blade Element Theory neglects induced elements of flow characteristics, this mathematical proof is limited from lightly to moderately loaded propellers, rotors, or fans. For heavy loads additional proving and/or testing is needed.

The lack of mathematical proof in heavily loaded cases does not mean a limitation of applicability of the Stallfree Technology.

3. Performance

Major characteristic of the new Stallfree Technology is the unmatched speed-range of operation. The whole subsonic speed-range can be flown with a Stallfree propeller-based propulsion system all the way keeping the near peak efficiency level.

Practically, any airspeed that a traditional propeller can be designed for falls within the regulation range of the Stallfree propeller.

Using present day’s variable pitch propellers – at an acceptable level of efficiency – about three different designs together could cover the regulation range of one single Stallfree propeller.

Turbofans and certain turboprops are capable to cover this range, however at a low average efficiency and, mostly, with rather poor takeoff/hover performance. See more at  https://stallfreepropellers.com/turbofan-concept-upgrade/